10 papers in Geology in China won "Frontrunner 5000——Top Articles in Outstanding S&T Journals of China "
"Geology in China" indexed in World Journal Clout Index (WJCI) Report of Scientific and Technological Periodicals (2021)
"Geology in China" selected as the Source Journal of "Outstanding S&T Journals of China (2020) "
Editor in Chief：HAO Ziguo
Established in：1953
ISSN： 1000-3657
CN： 11-1167/P
Domestic postal code：2-112
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OUYANG Yuan, LIU Hong, LI Guangming, MA Dongfang, ZHANG Linkui, HUANG Hanxiao, ZHANG Jinghua, ZHANG Tengjiao, LIU Xiao, ZHAO Yinbing, LI Fu
2023,50(2):303-330, DOI: 10.12029/gc20201026001
Abstract:
The paper is the result of geological survey engineering.
[Objective] The core problem of prospecting prediction is the nonlinear relationship between mineral distribution and mineral-controlling geological factors. Big data and machine learning technology have shown great advantages in solving such complex nonlinear relationship problems. The prediction dataset of small-scale geochemical remote information has the characteristics of high and extremely unbalanced, which is difficult to adapt by traditional logical assumptions or statistical analysis. Therefore, this paper attempts to introduce the random forest algorithm into the field of small-scale prospecting to explore the application of big data and machine learning technology in small-scale mineralization prediction.
[Methods] In recent years, several Porphyry-epithermal copper polymetallic deposits (such as Luerma, Bolazha, Daruo, Hongshan, and Luobuzhen, etc.) have been discovered in the western Gangdise mineralized belt, which proved that the western Gangdise belt has great prospecting potential for porphyry and epithermal Cu-Au polymetallic deposits. Combined with the comprehensive information of typical deposits, regional geology, geophysics, geochemistry, and remote sensing, this paper uses the random forest method to carry out the prospecting prediction of porphyry and epithermal Cu-Au polymetallic deposits in the western Gangdise belt.
[Results] This work has delineated 11 porphyry copper polymetallic prospect areas (including 2 levels I prospect areas, 3 level II prospect areas, and 6 level III prospect areas), of which Luobuzhen, Dajiacuo, Daruo, Balaza, Gaerqiong, and Budongla have great prospecting potential and are expected to find new ore deposits or points.
[Conclusions] The under-sampling random forest prediction model based on big data machine learning is expected to adapt to the high-dimensional and extremely unbalanced characteristics of prediction data of comprehensive geophysical and geochemical remote information and provide direction for regional prospecting prediction at the scale of the metallogenic belt. The prospective area determined in this work is expected to find new deposits (points), which opens a new vision for ore prospecting and exploration in the Gangdise metallogenic belt. -
WANG Runsheng, HAO Xingzhong, HU Lei, CHEN Hongjie, LIU Hui, CHEN Fangbo, YU Lu, LIU Wei, FANG Lei, KANG Yiming
2023,50(2):331-346, DOI: 10.12029/gc20210817001
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] A nearly N-S trending gravity and magnetic anomaly zone with certain homologous characteristics was identified in the Qihe-Yuchen ore concentration area, Shandong Province. In the early stage, thick skarn iron-rich deposits were successively revealed in the northern Litun and southern Dazhang gravity and magnetic anomalies, and great progress has been made in iron ore exploration. However, the Pandian anomaly area, the central part of the ore concentration area is covered by ultra deep Cenozoic, with small scale and weak intensity, while the geophysical information of deep iron ore body is greatly weakened, and the ore-induced magnetic anomaly is covered by the large-scale magnetic anomaly of diorite to a certain extent, which makes it difficult to identify and extract. Therefore, no prospecting breakthrough has been made in-the Pandian anomaly.-
[Methods] This article fully combines the successful prospecting experience of gravity and magnetic exploration in adjacent mining areas. From known to unknown, the plane analysis and profile quantitative inversion of Pandian gravity and magnetic anomalies were carried out, and the whole process interpretation of structural framework division, delineation of metallogenic geological body, anomaly analysis and 2.5D joint inversion is realized in the study area.
[Results] Based on comprehensive study of high-pricision gravity and magnetic data, the deep prospecting information under the ultra deep overburden is obtained,-and finally achieved a new prospecting breakthrough of skarn type rich iron ore in the central part of Qihe-Yucheng ore concentration area.-The three gravity and magnetic anomalies in the ore concentration area are closely related, which proves that the three iron deposits of Dazhang, Pandian and Litun are in the same nearly north-south neutral magmatic rock belt, opening up another important new prospecting space in the Qihe-Yucheng ore concentration area.
[Conclusions] The prospecting results provide important reference and instructions for further deep prospecting under ultra deep overburden. At the same time, it shows that there is a broad prospecting prospect for skarn iron-rich ore in Qihe-Yucheng ore concentration area. -
LIANG Jiangang, QIN Xilin, KUANG Haiyang, SUN Dapeng, WEI Jianping, CHEN Long
2023,50(2):347-358, DOI: 10.12029/gc20200116002
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] During the exploration of sandstone-type uranium deposits, the seismic exploration and traditional wave impedance inversion can effectively distinguish sandstone and mudstone, whereas the small difference of wave impedance cannot distinguish whether the sandstone contains uranium.
[Methods] In order to find favorable uranium-bearing sand bodies, this paper attempts to reconstruct wave impedance by combining acoustic curve with natural gamma curve, which is most sensitive to uranium ore bodies, so as to improve the inversion ability to uranium-bearing reservoir stratum. This work can make up for the defect that the traditional impedance inversion has no significant geophysical difference of uranium-bearing sand bodies and barren sand bodies.
[Results] It has been verified by several drilling cases, and this method effectively enhances the describing ability of rock properties with wave impedance inversion. It also effectively reduces the scope of prospecting and improves the ore finding rate of drilling verification.
[Conclusions] Reconstructed wave impedance inversion using natural gamma curve is worthy to be popularized in the exploration of sandstone-type uranium deposits by using petroleum data. -
ZHANG Wei, ZENG Zhaoguang, ZHOU Jun, JI Guosong, XU Xuegui, LIU Guanglei, LU Jianbao
2023,50(2):359-375, DOI: 10.12029/gc20200207001
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] Accomplished by the gradual depletion of mineral resources of shallow laterite-type gold deposits, e.g., Baozidong in Getang area, it is essential to detect deep alternative resources. Based on the metallogenic prediction factors such as regional metallogeny, geophysical and geochemical anomalies, and typical deposit characteristics, the Si/Ca interface between carbonatite in Permian Maokou Formation (P2m) and clasolite of Longtan Formation (P3l) at the footwall of the Haimagu ore controlling fault show an ideal prospect for interface-type gold deposits.
[Methods] The broadband magnetotelluric (BMT) method was introduced to imagine the electrical structure of 0-2 km depth in the southwest section of the Haimagu fault. The low resistivity zones revealing by the BMT inversion imply the Haimagu fault with multi-stage activity. In the early stage (before the Middle Permian), Haimagu fault is a tensile normal fault dipping to the northeast, and is a compressive reverse fault in the late stage (after the Early Triassic), dipping to the southeast with angel of 70°-80°. According to the gradient zone of high and low resistivity zone, it is inferred that the interface between Maokou Formation and Longtan Formation features paleo-karst landform with relative uplift and depression in the deep.
[Results] As for the metallogenic model, e.g., prospecting criteria and regional geophysical and geochemical anomalies of the typical deposits in this area, it is considered that the northwest of Haimagu fault with little exploration is worth drilling the deep resource potential.
[Conclusions] The combination technology of shallow and deep exploration (element geochemical anomaly and broadband magnetotelluric detection technology) can optimize to determine target areas. The relative uplifts of P2/P3 and Si/Ca interface adjacent to the Haimagu fault are favorable for drilling verification. -
ZHAO Hongbo, ZHU Zhitong, LIANG Tao, ZHAO Zhitao, ZHU Disi, SHAN Wenjun, LIU Wenwu, HE Yuanxin
2023,50(2):376-394, DOI: 10.12029/gc20210913002
Abstract:
This paper is the result of oil and gas survey engineering.
[Objective] Focusing on the scientific and technological task of shale gas investigation in the Yangtze River economic belt, China Geological Survey has deployed and implemented 173 shale gas exploration wells, completed more than 310000 m of drilling footage in recent years. Major breakthroughs in the shale gas investigation of Sinian system, Cambrian system, and Silurian system, and important discoveries in the shale gas investigation of Permian system has been achieved. It opened new areas, new strata, new types, and new insights of shale gas exploration. The basic geological survey wells are used to drill cores with low cost and short cycle. They are generally deployed in new blocks and new strata with insufficient data from adjacent wells. Aiming to provide technical support in drilling engineering for shale gas investigation.
[Methods] This article analyzes the related research progress of drilling projects deployed and implemented by China Geological Survey over the past decade, and a series of drilling technologies achieved have been classified and summarized.
[Results] The high-efficiency shale gas drilling equipment and technology system based on the innovative development of geological drilling equipment and technology are summarized:(1) Surface equipment for shale gas geological survey wells has been formed, including improved vertical shaft drilling rig suitable for well control safety of shale gas wells, drilling fluid solid control circulation system meeting the requirements of green exploration, etc.; (2) High-efficiency coring tools and drilling technology, focusing on the coring tools such as large-diameter wireline coring tools, KT series coring tools, inverted tower drilling tool assembly technology, air pipe following technology, etc.; (3) The research progress of high efficiency coring bits is described, including three types of bits, such as special-tooth PDC bits, impregnated block bits and impregnated diamond bits, and their application effects; (4) The progress of safe drilling technology and complex treatment is briefly discussed. The shale gas exploration drilling fluid technology, pressure control drilling technology, and drilling complex treatment such as lost return and sticking is introduced. In addition, the direction of shale gas drilling technology research is given.
[Conclusions] The review of above research progress can provide useful reference for shale gas exploration drilling engineering design and construction. -
XING Kai, ZHU Qing, ZOU Xiehua, LONG Tao, LIU Jun'an, WEN Pengfei, NIU Maolin, GU Benjie, ZHU Haibi, MU Yiwei
2023,50(2):395-409, DOI: 10.12029/gc20220909004
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] In recent years, the global economic industry structure and energy supply structure have transformed to green and low-carbon with the accelerated development of new energy industry. Understanding the development status and trend of the global lithium resource industry chain under the background of new energy would help us provide basic insights for the sustainable development of the global lithium industry and relevant references for the government and enterprises to improve the competitiveness of the lithium resource industry chain.
[Methods] This paper reviews the specific impact of the increasing demand for new energy on the global lithium resource industry chain in terms of resource supply and demand, smelting and processing, end consumption, and recycling.
[Results] Under the background of new energy, the global terminal consumption of lithium resources, especially in the field of power battery, has continued to flourish; the global demand for lithium has grown rapidly, while the price has continued to rise under the misplacement of supply and demand. With the rising importantance of lithium resources in the world, major economies have listed it as a key mineral, which conducting a series of policies to ensure the safe supply of lithium resources in their own countries, strengthen the recycling of lithium resources, and promote the transformation and upgrading of industrial structure. The production mode, structure and development goal of the enterprises are developing in the direction of low-carbon, integration and sustainability.
[Conclusions] Developing efficient and clean energy has become an effective way to solve energy and environmental problems, and transportation electrification and energy storage make the global demand for lithium resources continue to increase rapidly. These changes have obvious impact not only on the supply pattern of lithium resources in the upstream, but also on the production and processing in the midstream and consumption structure in the downstream end of the industrial chain. However, the transmission and specific impact on every link of the industrial chain are uneven. -
Distribution characteristics, main types and exploration and development status of beryllium deposit
ZHANG Sen, JU Nan, WU Yue, GUO Changlai, MA Wei, ZHOU Yongheng, ZHANG Yanfei
2023,50(2):410-424, DOI: 10.12029/gc20210723002
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] As the lightest alkaline earth metal, beryllium has become an excellent functional and structural material. Due to its special physical and chemical characteristics such as density, stiffness and melting point, it has great scientific and economic value for researching the genetic mechanism, exploration and development.
[Methods] In this paper, the characteristics, genesis and exploration technology of typical beryllium deposits in the domestic and overseas are systematically sorted out and summarized. The metallogenic rules are summarized from time and space scales by means of similarity and analogy, and the exploration, development and utilization suggestions are also put forward.
[Results] Beryllium deposits can be divided into endogenous and exogenous types. Exogenous beryllium deposits can be subdivided into different deposit types related to weathering or metamorphism. According to the alkali-aluminum properties of magma system, endogenous beryllium deposits can be subdivided into peraluminous, metaluminous and peralkaline metallogenic systems. According to the fluid evolution stage, it can be subdivided into magma type, pegmatite type and magma hydrothermal type.
[Conclusions] From the perspective of metallogenic age, the beryllium mineralization in either peraluminous, metaluminous or peralkaline systems is concentrated in the Mesozoic. Yanshanian is the main metallogenic period of beryllium deposits. From the perspective of metallogenic structure background, the magma type is often produced in post-collision environments, the magmatic hydrothermal type is produced on the continental margin, and the pegmatite type is basically produced in the orogenic belt. Beryllium is one of the new materials, which will play an important role in energy conservation, emission reduction and carbon neutralization in the future. Research on comprehensive utilization and recovery technology of beryllium deposits should be strengthened. -
ZHOU Zuomin, LIU Xiaoyang, GONG Penghui, REN Junping, XIE Yu, SUN Kai, WU Xingyuan, HE Fuqing, HE Shengfei, ZUO Libo, ZHANG Hang
2023,50(2):425-441, DOI: 10.12029/gc20201106002
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] The formation of chromite is generally related to basic-ultrabasic rocks. However, the genetic mechanism of chromite deposit remains controversial. Deciphering the genesis of chromite deposit is of great significance for ore exploration.
[Methods] This review work summarizes the ore types, metallogenic age, ore body characteristics and genetic mechanisms of chromite based on previous research results. New perspectives are also provided.
[Results] The chromite resources and production are highly concentrated at South Africa, Kazakhstan, Finland and India, accounting for more than 95% of the global chromite reserves. The global chromite supply market is dominated by South Africa, Kazakhstan and Turkey. There are two major chromite types, namely primary and secondary chromite. Primary chromite is mainly stratiform and podiform, while secondary chromite is mainly seashore placer chromite (or marine placer chromite). The stratiform chromite deposit is commonly huge in scale and formed associated with the basic-ultrabasic intrusions within stable cratons. The podiform chromite deposit is widely distributed and closely symbiotic with ophiolite, but the scale of this deposit is generally small. There are obvious differences in the occurrence, fabric, structure and paragenetic association of the two different chromite types. The podiform chromite is mainly formed in the Phanerozoic, with a small amount formed in the Meso-Neoproterozoic. The stratiform chromite is mainly formed in the Proterozoic and concentrated in the Paleoproterozoic.
[Conclusions] The genetic model of the stratiform chromite deposit is less controversial, mainly focusing on the contamination mechanism of salic roof rocks and the magma mixture. In contrast, little consensus has been reached on the genetic models of podiform chromite. The enrichment mechanism of chromium is a key issue for more scientific constraints in the future. -
CHEN Zhenyu, ZHAO Yuanyi, LI Xiaosai, LIU Guannan, ZHANG Jiawen, LI Ruimin
2023,50(2):442-458, DOI: 10.12029/gc20191130001
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] Mineral resources are an important support for economic and social development, and their carrying capacity is the fundamental basis for determining the regional economic structure and development model. It is of great significance to carry out the evaluation of the carrying capacity of regional mineral resources to promote the sustainable development and utilization of regional mineral resources.
[Methods] In this paper, the coal mine resources of Weixin County of Yunnan Province are taken as the research object, and the evaluation index system is constructed by two evaluation factors of carrying background (proportion of resources available, PRO) and carrying state (mining development index, MDI). On this basis, the carrying capacity of coal mine resources in Weixin County is evaluated, and the rationality of the evaluation system of mineral resources and the weight distribution of each sub index is discussed with Weixin County as the evaluation pilot.
[Results] Among the ten townships in Weixin County, there are no townships with "large" coal mine resources carrying capacity, only two with "relative large" carrying capacity, two with "medium" carrying capacity, and six with "small" carrying capacity.
[Conclusions] In the evaluation system of bearing capacity of mineral resources, both positive and negative indicators should be considered equally, accounting for about 50% respectively. In addition, the distribution of the weight of each sub indicator should also closely correspond with the economic, social and environmental policies of the region at that time. -
PEI Lixin, YE Siyuan, HE Lei, ZHAO Guangming, YUAN Hongming, DING Xigui, PEI Shaofeng, LI Xue, WANG Faming, EDWARD A. Laws
2023,50(2):459-478, DOI: 10.12029/gc20220218001
Abstract:
This paper is the result of environmental geological survey engineering.
[Objective] As one of the countries with the most diverse types of wetlands, China has a wetland area of 53.60 million hectares, ranking fourth in the world. However, with rapid population growth and economic development, China is facing conflicts between wetland protection and economic development in recent decades. Analyzing the current status of wetland resources and development, as well as the reasons for their degradation in China, is a prerequisite for discussing wetland management strategies.
[Methods] Based on the analysis of the characteristics and current status of wetland resources in China, this article systematically summarized the driving factors of wetland loss and degradation, and proposed wetland management recommendations.
[Results] China is rich in wetlands, which not only provide functions such as water purification, flood control, climate regulation, but also provide rich resource guarantee for local economic development, thereby developing a series of utilization modes with good economic and social benefits. At the same time, China attaches great importance to wetland protection and has issued and implemented a series of wetland protection policies and projects, with a wetland protection rate of 52.65%. However, under the dual impacts of human activities and climate change, wetland shrinkage in China is still widespread, and there are still many scientific issues need to be resolved in wetland protection and restoration management practices.
[Conclusions] The current trend of wetland loss and degradation in China is still severe. To further strengthen wetland protection, it is necessary to strengthen comprehensive multidisciplinary research on the earth system and consider the constraints of economic feasibility and social demands, in order to formulate a sustainable management plan that meets the requirements of social and economic development and ecological science. -
SUN Zhangtao, YU Zhengwei, SHU Siqi, XU Chuangsheng, SHU Yang
2023,50(2):479-494, DOI: 10.12029/gc20221027001
Abstract:
This paper is the result of ecological geological survey engineering.
[Objective] It is the common responsibility of all countries to protect the ecological environment and promote the sustainable development. The nationwide evaluation of ecosystem service is conducive to the promotion of ecological environment protection and the establishment of the modernization of harmonious coexistence between human and nature.
[Methods] The study on the evaluation of ecosystem service has become a hot topic in the field of ecological sciences. Based on the evaluation method of ecosystem service proposed by Costanza et al. in 2014, this study establishes a dynamic evaluation model of ecosystem service by using the Consumer Price Index, the Purchasing Power Indexes of US dollar and Chinese RMB, which is used to evaluate the ecological system services of Chinese provincial land with the data of the Third National Land Survey, and studies the spatial distribution of ecosystem service value of Chinese provincial land via Hotspot analysis technique.
[Results] The value of ecological system services of Chinese mainland in 2019 is 35.79 trillion RMB. Qinghai province is located in a hotspot area, Heilongjiang province is located in a sub-hotspot area, Guizhou province and Chongqing municipality are located in sub-Coldspot, and Shannxi Province is located in Coldspot area.
[Conclusions] In terms of the geological background and ecological characteristics of the so-called "Two Zones and Three Belts" which involve the Qinghai-Tibet plateau, Northeast zone, Yellow River basin, Yangtze River basin, and coastal zone, we propose to carry out the integrated ecological geological survey of mountain, water, forest, cropland, lake, grass, and sand. The first is to carry out investigation on glacier melting and permafrost thaw, degradation of grasslands and desertification of land in Qinghai-Tibet area. The second is to carry out investigation on forest quality, ecological diversity, and wetland resources in Northeast China. The third is to carry out investigation on ecological degradation in the upstream, water and soil loss in the midstream, and the wetlands shrinkage in the downstream of the Yellow River. The fourth is to carry out investigation on water conservation in the upstream, the rocky desertification and soil erosion of Karst area in the midstream, and wetlands degradation in the downstream of the-Yangtze River. The fifth is to focus on the investigation of typical marine ecosystems such as coastal erosion and mangroves. -
TIAN Fujin, MA Qingshan, ZHANG Ming, TANG Zhimin
2023,50(2):495-505, DOI: 10.12029/gc20220810001
Abstract:
This paper is the result of hydrogeological survey engineering.
[Objective] The Xin'anjiang River Basin is an important ecological security barrier in East China, and its governance is long-term, arduous, complex, and repetitive. Scientifically evaluating the water environment quality of the basin and identifying the key polluted areas and major pollution factors could provide an important basis for promoting the improvement of the ecological environment of the river basin.
[Methods] Based on the water quality data of 88 monitoring points of Xin'anjiang River basin, the principal component analysis method was used to optimize the evaluation index system of water quality, and then the entropy weight method was adopted to calculate the weight of each index and the comprehensive water quality index of each monitoring point. Moreover, the comprehensive index map of water quality was drawn by the spatial analysis function of GIS.
[Results] The results show that the comprehensive index of 88 monitoring points ranged from 0.02-1.313, and the environmental quality of surface water in the basin was generally good, mainly for class III. The water quality of Zhejiang section was better than that of the Anhui section. The key pollution area was distributed in the Xiuning-Shexian-Huizhou district, forming two pollution centers in Qiankou Town, Yansi Town-Sancun Town. Moreover, TN, TP and NH3-N were the main pollution indicators of the basin, where TN was a global pollutant, TP and NH3-N were regional pollutants.
[Conclusions] The water quality evaluation model composed of principal component analysis and entropy weighting method avoids the repeated selection and the subjectivity of weight assignment for evaluation index, which could efficiently evaluate the complex index system of water environment and better reflect the actual spatial distribution of water quality. It is feasible and practical in water quality evaluation. -
WANG Peng, ZHAO Jun, YAN Xiaojuan, YANG Tao, ZHANG Jing, MA Shangwei, ZHANG Daojun
2023,50(2):506-520, DOI: 10.12029/gc20220428003
Abstract:
This paper is the result of comprehensive survey engineering of natural resources.
[Objective] It is the inherent demand of ecological protection and high-quality development to measure and analyze the spatio-temporal differentiation of urban land use efficiency in the Yellow River basin.
[Methods] Based on municipal input-output data from 2004-2017, we introduce SFA (Stochastic Frontier Analysis) and Spatial Association Model to measure the urban land use efficiency of 83 cities located in the Yellow River basin.
[Results] The urban land use efficiency of the Yellow River Basin showed an obvious increasing trend during 2004 to 2017. The efficiency growth rate of cities in the upper reaches of the Yellow River basin is faster than that of cities in the middle and lower reaches. The efficiency was still in the middle and low level across the whole area.It still presented great differences of the urban land-use efficiency across the whole the Yellow River basin, but the leadership of central cities played a tremendous role in the urban agglomeration, and the high-efficiency areas (first and second types) were gradually expanding from "Spots" to "Patches", while the middle and low-efficiency areas gradually reduced. The differences of inter-urban agglomeration and differences among the upper, middle and lower reaches gradually converged. The land use efficiency among cities had positive spatial correlation and the agglomeration level was enhanced year by year. The Lisa (local indicators of spatial association) was characterized by polarization. Not only the High-High agglomeration (H-H type) area were mainly distributed in Shandong Peninsula, and gradually clustered into pieces, but also it appeared in the Central Plain urban agglomeration for the first time. The areas with a Low-High agglomeration (L-H type) pattern were transformed from Weifang, Shandong Province to Bayannur, Inner Mongolia. And the High-Low agglomeration areas(H-L type) were concentrated in Lanzhou. The Low-Low agglomeration (L-L type) areas were distributed in the national-level concentrated contiguous poverty areas such as Liupan Mountain area and Qinba Mountain area.
[Conclusions] It is suggested that as a whole, the Yellow River basin should be planned and developed in a coordinated way, and more attenion should be paid to the endogenous impetus of urban development individually. The spatial spillover effect which the central cities make-should be given full play to, and resources should be allocated and shared rationally through the optimization of the scale and structure of capital investments. In addition, to better serve the transformation of urban economic development from labor-intensive and capital-dependent to technology-driven, the policy of differentiated ecological protection and high-quality development should be implemented in the upper, middle and lower reaches of the Yellow River Basin. -
Lü Liuyan, QIAO Weitao, CHEN Ren, LI Jing, YU Ning, HU Xinrui, LIU Qin
2023,50(2):521-532, DOI: 10.12029/gc20190321003
Abstract:
This paper is the result of geological survey engineering.
[Objective] The Qingshuijiang Formation in Kaiyang area of Central Guizhou is a set of epimetamorphic terrigenous clastic rocks intercalated with pyroclastic rocks, which formed at the margin of the Yangtze block in Neoproterozoic. In order to accurately determining the depositional age, the provenance and the paleogeographic pattern of the Qingshuijiang Formation, the sedimentary characteristics of terrigenous clastic rocks and the chronology of pyroclastic rocks are studied in this paper.
[Methods] Based on the detailed geological survey, the detrital zircon U-Pb age of the tuffites at the top of this Formation was determined by LA-ICP-MS analysis, and the regional stratigraphic correlation was carried out.
[Results] Zircon U-Pb ages are divided into two groups, 2488-1821 Ma in Paleoproterozoic and 838-779 Ma in Neoproterozoic, respectively, with a weighted average of (802±24) Ma for the youngest age group. The statistical results of pyroclastic content shows that the magma activity in this period has obvious episodic distribution and periodicity. Regional stratigraphic correlation results show that the exposure nature of the Qingshuijiang Formation in Kaiyang area is similar to Tongren and Yinjiang area, and may be equivalent to the bottom of the Qingshuijiang Formation in southeast Guizhou area.
[Conclusions] The latest depositional age limit of the Qingshuijiang Formation in Central Guizhou is about 800 Ma. The provenance mainly comes from Sichuan-Yunnan-Guizhou region on the western margin of the Yangtze Landmass. and the abundant volcanics may come from the second to third episodes of tectonic magmatic activity during the breakup of the supercontinent in the middle Neoproterozoic. The sea-land conversion occurred in the subsequent Xuefeng movement, and formed an ancient land extending in the northeast with a higher distribution of altitude in the south than the north, which established the paleogeographic framework of the Nanhua period in the middle Neoproterozoic. -
LIU Zining, DOU Lei, ZHANG Wei, ZHU Wenbin, MO Bin, CHEN En, JIA Lei
2023,50(2):533-542, DOI: 10.12029/gc20191225003
Abstract:
This paper is the result of geological survey engineering.
[Objective] A large suite of carbonates developed in the Early Carboniferous in the Lianzhou area of northwest Guangdong, and the representative stratigraphic section of the Lianxian Formation is an ideal stratigraphic section for studying carbonate deposition in this period. The bottom boundary of the selected stratigraphic section of the Banling Village of the former Lianxian Formation is unclear and the outcrop is severely damaged, which has lost the functional value of the stratigraphic section. There is an urgent need to find a new stratigraphic section in the Lianxian Formation to provide a reference for the stratigraphic stratigraphy of the Lower Carboniferous and regional geological survey studies in the area.
[Methods] Tematically studied by means of large scale sectioning, rock identification and paleostratigraphy of the stratigraphic section in Longtan Shijietou village of Jiubei, Lianzhou city, Guangdong. The stratigraphic characteristics of the sequence were obtained and the age of the bottom boundary was determined.
[Results] Based on the evolutionary sequence of foraminifera, the disappearance of foraminiferal Quasiendothyra kobeitusana, Q. konensis and the first occurrence of Bisphaera irregularis birina reveal that the boundary between Devonian and Carboniferous in the Lianzhou area of northwestern Guangdong passed through the middle of the granular tuff at the top of the Changlai Formation. Combined with the stratigraphic, the developmental age of the Lianxian Formation can be the restricted to the Early Carboniferous Dunei stage.
[Conclusions] This section is the largest section with continuous deposition of Early Carboniferous early carbonate rocks known in the region, with complete stratigraphic sequence development and clear top and bottom interfaces, and is the most ideal secondary stratigraphic section found in the Lianxian Formation. This lays the foundation for the establishment of the substratigraphic type (reference section) of the Lianxian Formation. The above results are of great significance for the construction of the regional stratigraphic framework in northwestern Guangdong, the conduct of regional stratigraphic delineation and comparative studies, and the improvement of the regional geological background. -
ZHANG Qiong, XU Wenli, XU Xu, WEN Huaguo, ZHANG Linpu, GUO Gengsheng, HE Chuan
2023,50(2):543-556, DOI: 10.12029/gc20191119002
Abstract:
This paper is the result of oil and gas exploration engineering.
[Objective] The third member of Shahejie Formation of the Paleogene is the most important oil and gas horizon in Fulin sag, Zhanhua sag, jiyang sag, Bohai Bay Basin, and it has the essential scientific and guiding significance of strengthening the reservoir characteristics of Shahejie Formation, analyzing the main controlling factors of the reservoir, and guiding the reservoir prediction and oil and gas exploration engineering and resources of Shahejie Formation in the area.
[Methods] Based on the petrography and reservoir physical property data, this paper is aiming to dicipher the origin of the sandstone reservoirs of Paleogene Shahejie Formation the Zhanhua sag, Bohai Bay basin.
[Results] The thin sections observation and sem analysis show that the lithofacies of the reservoirs are consist of feldspathic lithic sandstone and lithic feldspar sandstone, with low compositional and structural maturities, indicating that they rapidly deposited in the environment proximal to provenance. The reservoir space type of the reservoir is mainly residual primary intergranular pores, intergranular solution pores and intragranular solution pores, mainly low medium porosity and ultra-low permeability pore type reservoirs. The development of high-quality reservoirs is controlled by sedimentary microfacies and diagenesis. The sedimentary microfacies are the basis for the development of high-quality reservoirs, and cementation and dissolution are the key factors for the development of high-quality reservoirs.
[Conclusions] (1) The rock types in the study area were mainly feldspathic lithic sandstone and lithic feldspar sandstone. (2) It is generally a low-to-mesoporous and ultra-low permeability reservoir; (3) High-quality reservoirs in the study area are mainly distributed in braided river delta distributary channels and estuarine bars; (4) Compaction and cementation are the main destructive diagenesis in the study, while dissolution has constructive diagenesis on reservoir physical properties. -
ZHAO Jichang, TANG Qingyan, LIU Yonggang, SU Tianbao, WANG Zhen, HU Xiaochun, YANG Zhenxi, SONG Hong, ZHANG Jiahe
2023,50(2):557-572, DOI: 10.12029/gc20210402003
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] Due to the relatively low research level of crystalline graphite deposits in the Aobaoshan crystalline graphite deposit-concentrated area in Dunhuang block, the protolith restoration and paleoenvironment of this area are studied profoundly, which will provide a geological foundation for metallogenic regularity.
[Methods] The protolith of the metamorphic rocks in the Aobaoshan crystalline graphite deposit-concentrated area is restored using the method of petrochemistry, and the paleotectonic environment of its formation is discussed.
[Results] Two-mica quartz schist, biotite plagioclase gneiss and plagioclase amphibolite are enriched in the light rare earth elements. The plagioclase amphibolites have less K2O contents than Na2O. They are weakly depleted in Nb and Ta, and strong depleted in Zr and Hf, and have the ratios of LREE/HREE ranging from 2.21 to 6.97, indicating the weak fractionation degree of light and heavy rare earth elements. The biotite plagioclase gneisses and two-mica quartz schists have higher K2O contents than Na2O. They show the enrichment in large ion lithophile elements, such as Rb and K, and the depeletion in Ba, Nb, Ta, Zr, Hf, Ti and Sr, and obvious Eu negative anomalies. The average ratios of LREE/HREE of the biotite plagioclase gneiss and two-mica quartz schist are 12.44 and 8.89, respectively, indicating strong differentiation of light and heavy rare earth elements.
[Conclusions] It is inferred that the protoliths of the metamorphic rocks from the Aobaoshan crystalline graphite deposit-concentrated area were formed in shallow water area with weak hydrodynamic environment. The protoliths of the plagioclase amphibolites in the Aobaoshan crystalline graphite deposit-concentrated area are subalkaline basic volcanic rock, and they were formed in an island arc. The protoliths of biotite plagioclase gneisses and two-mica quartz schists are shale and clayrock, and they were formed at active continental margins. The paleosedimentary environment was oxygen-rich interactive marine and terrestrial deposition in dry climate zone, and the paleowater medium was brackish water. -
WANG Xiaodi, SUN Chuanmin, JIA Xiaohui, ZHANG Liguo, ZHOU Dai
2023,50(2):573-585, DOI: 10.12029/gc20190429004
Abstract:
This paper is the result of geological survey engineering.
[Objective] Indosinian basalt, exposed in the northern part of the Mashan Complex in southeast Guangxi province, is a key rock probe for the study of Indosinian movement in South China. It has been seldom researched so far, which restricts the recognition of evolution of tectonic setting in South China.
[Methods] We carried out zircon U-Pb geochronology, geochemistry, Sr-Nd isotopic geochemistry and petrogenesis of the Mashan basalt.
[Results] The results show that the LA-ICPMS zircon U-Pb age of the Mashan basalt is (246.7±1.5) Ma, (MSWD=0.16). The basalt belongs to potassium trachybasalt with high alkali (K2O+Na2O=5.21%-8.02%), especially potassium (K2O=2.59%-4.96%), and is enriched in large ion lithophile elements (Rb, Th, U, K, Pb, LREE) but depleted in-high field strength elements (Nb, Ta, P, Ti, HREE). The Sr-Nd isotopes of the Mashan basalt have affinity with enriched mantle (EMⅡ).
[Conclusions] The geochemical characteristics of the Mashan basalt exhibit shoshonitic features, and is mainly a product through fractional crystallization without obvious crustal contamination. It was probably derived from partial melting of phlogopite- and garnet-bearing lithospheric mantle (>80 km), which was metasomatized by subducted crustal materials. The basalt is developed in an intraplate setting, likely to be shaped by magmatic eruption and intrusion upwards through favorable space created by the extension in the later stage of the Indosinian thrust-nappe structure. -
TAO Qin, HAN Runsheng, ZHAO Dong, WU Peng, TIAN Xufeng, ZHAO Taicheng, YANG Hang, ZONG Zhihong, DENG Anping
2023,50(2):586-604, DOI: 10.12029/gc20191211003
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] The Huangshaping Cu-Sn polymetallic deposit is one of the typical representatives of the magmatic hydrothermal metallogenic system in southern Hunan, China. In order to deepen the diagenetic and metallogenic mechanism of the deposit and efficiently guide the exploration of deep prospecting, it is necessary to reveal the polymetallic mineralization-alteration zone rule related to the concealed granite porphyry, and construct the deep mineralization-alteration spatial zoning model.
[Methods] Applying the large-scale altered lithofacies location prospecting and prediction method for hydrothermal deposits, and the geochemical analysis of rock and mineral for tunnel sections in the typical levels of -136 m, -176 m and -256 m, the intensity change of mineralization-alteration, mineral paragenetic association and its spatial zoning characteristics were analyzed, and the transformation rules of ore-forming elements, element associations and element ratios were discussed.
[Results] The current study constructed mineralization-alteration zoning model:from porphyry (internal zone) to contact zone to surrounding rock (outer zone) with scheelite-molybdenite (pyrite) mineralized-silicified-sericitized granite porphyry zone (Ⅰ) → magnetization (scheelite-cassiterite) mineralized garnet skarn zone (Ⅱ-1) → scheelite-molybdenite-pyrrhotite mineralized garnet skarn zone (Ⅱ-2) → lead-zinc mineralized crystalline limestone zone (Ⅲ) → strong calcitization limestone zone (Ⅳ). The main mineral assemblages of in the corresponding zones are:Quartz + (Pyrite + Sericite) → Magnetite + Diopside + Wollastonite + Epidote + Chlorite + (Scheelite + Cassiterite + Pyrite + Garnet) → Scheelite + Molybdenite + Pyrrhotite + (Cassiterite + Chalcopyrite + Pyrite + Sphalerite + Galena) + Garnet + Vesuvianite + Diopside + Hornblende + Fluorite + Epidote + Chlorite + (Quartz + Calcite) → Galena + Sphalerite + (Pyrite) + Calcite + Quartz → Calcite + Quartz. The distribution rule of mineralized elements in each alteration zone was revealed:W, Mo → Fe, W, Sn (Bi, Mo) → W, Sn, Bi, Mo (Cu) → Pb, Zn (W, Sn, Cu) → Pb, Zn, Ag.
[Conclusions] The mineralization-alteration zoning rule of the deposit was obvious from the rock mass as the center to the surrounding rock on both sides. The transformation rules of characteristic mineral assemblage and mineralization indicator elements in each zone have an obvious indication of the occurrence position of the ore body. -
ZHEN Shimin, ZHA Zhongjian, WANG Dazhao, LIU Jiajun, PANG Zhenshan, CHENG Zhizhong, XUE Jianling, WANG Jiang, BAI Haijun, LI Yang, CHEN Chao
2023,50(2):605-621, DOI: 10.12029/gc20190927002
Abstract:
This paper is the result of mineral exploration engineering.
[Objective] The Zhongshangou gold deposit is located in the north margin of North China Craton and the south side of Shangyi-Chongli-Chicheng deep fault. It is one of the typical gold deposits in Zhangjiakou-Xuanhua gold concentration area, Hebei Province. This paper discusses the characteristics and evolution of ore-forming fluids, in order to provide a theoretical basis for the exploration of the deposit.
[Methods] This paper summarizes the regional mineralizing setting, geological characteristics of the mining area, ore body and ore characteristics. Representative samples from four metallogenic stages were selected to conduct research on fluid inclusion petrography and micro thermometry, hydrogen and oxygen isotopes, and helium and argon isotopes.
[Results] The results indicate that it can be divided into four metallogenic stages:K-feldspar-pyrite-quartz stage (I), milky white quartz-pyrite stage (II), smoky gray quartz-sulfide stage (III) and sulfide-poor-carbonate stage (IV). Gas-liquid two-phase primary fluid inclusions are mainly developed in each mineralization stage. The temperature measurement data of fluid inclusions show that the homogenization temperature and salinity of main ore-forming stage are respectively 210-250℃ and 6.01%-13.62%NaCleqv. Hydrogen and oxygen isotope show that δ18OH2O and δDV-SMOW values are respectively -2.97‰-6.96‰ and -94.6‰--80.2‰, which show that the δ18OH2O values drift to the atmospheric water line and show a linear change. Helium and argon isotope of the pyrite show that 3He/4He values are 1.82×10-7-9.24×10-7, 40Ar/36Ar values are 699.9-2200.4, R/Ra values are 0.13-0.66, radiogenic 40Ar* values are 55.89%-86.57%, and mantle derived helium values are 2.00%-10.86%.
[Conclusions] The ore-forming fluid has experienced a continuous evolution process from medium-high temperature and medium-low salinity to low temperature and medium-low salinity. The main ore-forming stage experienced strong boiling. In the late stage of mineralization, there mixed in a large amount of meteoric water. With the development of mineralization, the proportion of mantle derived materials in mineralization increased gradually. The ore-forming fluid has the characteristics of magma fluid mixed with the crust and mantle. To sum up, the ore-forming fluid of Zhongshangou gold deposit is characterized by the intrusive rock related telluride-gold deposit. -
LI Shengxi, HE Bi, YANG Bo, WEI Zhifu, TAO Gang, GAN Baoping, ZHAO Fei, SUN Pingyuan, ZHAO Zhenguan, HUANG Pengfei
2023,50(2):622-639, DOI: 10.12029/gc20190320001
Abstract:
This paper is the result of geological survey engineering.
[Objective] The Tagelake strip pluton, outcropped at the south Tianshan terrane in Southwestern Tianshan orogenic belt, is composed of monzogranites. Determining the formation mechanism of the monzogranites has important implications for the crust-derived magma origin and the time limit of subduction and ocean basin closure in South Tianshan Mountains.
[Methods] In order to determine the formation mechanism of the monzogranites, detailed zircon U-Pb geochronology, major elements and trace elements were firstly conducted.
[Results] LA-ICP-MS zircon geochronology study reveals that the monzogranites in the Tagelake area crystallized at (284.0±1.9)-(284.3±3.2) Ma, indicative of an Early Permian pluton. The results of major elements and trace elements reveal that the monzogranites display the characteristics of A-type granite:(1) The contents of SiO2 (70.92%-72.78%), K2O+Na2O (7.91%-8.44%) and A/CNK (0.89-0.99) are high, indicating that monzogranites are metaluminous rock and belongs to the high potassium calcium alkaline series; (2) The monzogranites are enriched in LREE (196×10-6-280×10-6) and depleted in HREE (22.8×10-6-28.2×10-6). Negative Eu anomaly is obvious, with δEu values of 0.51-0.64, and the monzogranites are characterized by fractionated chondrite-normalized REE patterns; (3) The monzogranites are enriched in Rb, Th, K and other large ion lithophile elements and depleted in Nb, Ta, Zr, P, and other high field strength elements.
[Conclusions] Combined with the regional tectonic evolution, it is considered that the Tagelake monzogranites were formed in the post-collision tectonic setting. -
DENG Min, CHENG Jinxiang, TANG Yong, BIAN Baoli, WANG Zhenghe, LI Kuizhou, WAN Youli
2023,50(2):640-642, DOI: 10.12029/gc20220305001
Abstract:
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YANG Wenbo, ZHOU Bin, FAN Peng, WU Zhongshan, HUANGFU Pengbin
2023,50(2):643-644, DOI: 10.12029/gc20220614001
Abstract:
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LIU Xuelong, TAO Xingxiong, ZHOU Yunman, ZHAO Chengfeng, LI Shoukui, ZHOU Jiehu, CAO Zhenliang, WEI Zhiyi, LI Fanglan
2023,50(2):645-647, DOI: 10.12029/gc20220627001
Abstract:
Volume 50,2023 Issue 2
In Focus
Reviews
Research Articles
Discoveries and Development
New and Highlights
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CUI Xiaodan, REN Jinghua, FAN Jian, XU Hongting, ZHOU Qiang, WANG Ziyi, ZHU Baiwan
DOI: 10.12029/gc20211125001
Abstract:
【Objective】In order to prove the health risk from the Cd pollution in typical cultivated soils in Jiangsu province, and understand the main geochemical factors to control rice seeds uptake of Cd in soil, and provide scientific evidences to cure Cd pollution. 【Method】1330 sets of rice-soil samples were systematically collected in the studied areas, and Cd, Pb, Hg, As, Cr, Cu, Zn, Se, Sb, TOC(Total Organic Carbon), pH, and CEC (Cation Exchange Capacity) in soil and Cd in rice seeds were determined by advanced testing methods such as ICP-MS, etc, the available Cd in soil was determined by calcium chloride extraction, and mastering the actual distribution data related to rice seeds Cd contents and elemental concentrations in soil. By the means of calculating their geochemical parameters and comparing its difference, developing correlation analysis and R-type cluster analysis, etc., and exploring main geochemical controlling factors to impact rice seeds uptake of Cd in soil, evaluating healthy risk in the local Cd polluted farmland.【Results】The available Cd concentrations are 0.0018~1.44mg.kg-1, their mean value is 0.265mg.kg-1, and the Cd concentrations are 0.13~30.0mg.kg-1 with an average amount of 2.11 mg.kg-1 in soil, and the rice seeds Cd contents are 0.0053~2.58mg.kg-1 with the mean amount of 0.478 mg.kg-1 in the studied areas. The available Cd in soil is the most important factor to control the rice seeds uptake of Cd, and the local Cd pollutants have spread to the food chain and human hairs in the farmland.【Conclusion】1) there are significant positive correlations between rice seeds Cd contents and the available Cd in soil, and its correlated coefficient (named r)is 0.54 without deleting anyone in the 1330 sets samples , if pH values being from 6.5 to 7.5 in soil, the positive correlated relationship between rice seeds Cd contents and the available Cd in soil is best with correlated coefficient maximum value of r=0.86. In addition to the available Cd, the following geochemical factors as to Cd, TOC, CEC, and pH of soil are also important to control rice seeds uptake of Cd, and there exist some significant or more significant positive correlation between rice seeds Cd contents and Cd concentrations too, and similar significant or more significant negative correlation between rice seeds Cd contents and pH, TOC and CEC in soil. In general, the factors order to impact rice seeds Cd absorption is the available Cd﹥Cd﹥pH﹥TOC≈CEC in soil; 2) as to pollution-free Cd farmland, the Cd carcinogenic health risk index (simplified CR value) increased by more than 85 times, the average amount of Cd concentration in the human hair samples increased by 1.09 times because of eating rice seeds with Cd over standard, and the Cd concentration of the soil solution was significantly increased higher in the farmland distributive area contaminated by Cd. Meanwhile, the rice seeds Cd contents and its relative health risk evaluation are more dependent on the soil effective Cd in those areas contaminated by Cd, it means that there are higher health risks or ecological security risks in those local farmland Cd pollution areas; 3) there are too significant correlation or obvious antagonism in soil between the available Cd and other geochemical factors such as Cd, pH, TOC, CEC and Se, and so on, which comprehensively regulate the Cd absorption of rice seeds , but the available Cd in soil is the most main one; 4）the Cd pollution is generally slight, and its healthy risk level is mainly mild from the cultivated land in Jiangsu province, if we can take appropriate restoration and treatment measures (for example deep tillage, etc.) in order to reduce the Cd, especially effective Cd content in soil, reasonably increase soil organic matter, improve soil pH, etc., block the migration of soil Cd to food chain and human bodies, the Cd polluted risk will completely be controlled, and produce qualified rice seeds to meet the social needs at last.
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ZHANG Xiaofei, ZHANG Xuebin, ZHANG Yongyi, Niu Shuyin, Sun Aiqun, WANG Yongli, FAN Hangyu, LI Mingchen, HAN Rongwen
DOI: 10.12029/gc20221207001
Abstract:
Abstract: This paper is the result of maring geological survey engineering. [Objective] The northwest of Bohai Bay is an area where the depositional environment changes frequently in North China Plain and is also the main depressed area of the neotectonics. Strengthening the stratigraphic research since Late Pleistocene in Northwestern Bohai Bay and analyzing the evolution process of the depositional environment is of great significance to the study of sea-level change and subsidence of coastal areas.[Method]Based on the three full coring boreholes QLT03, QEJ01 and NHG14 in the northwest coast of Bohai Bay, and by integrating the lithostratigraphic and biostratigraphic methods, AMS14C and optical stimulated luminescence dating are used to compare and analyze the collection boreholes in the adjacent area, discussing the depositional environment and its indications to transgression and tectogenesissince late Quaternary in the study area.[Result]The results show that early Late Pleistocene of the study area is the development period of delta plain and fluvio-lacustrine facies, the middle is the development period of floodplain-lacustrine facies and delta plain, the late is the development period of meandering stream- floodplain facies, and Holocene is the development period of delta plain- flood plain. The study area develops three phases of transgressive strata from bottom to top, namely, the third transgressive layer in early Late Pleistocene, the second transgressive layer in late Late Pleistocene and the first transgressive layer in Holocene. The scale of transgression has gradually strengthened from the ancient to the present. The transgressive layers in each phase are more consistent with the global sea level change and have good correspondence with the high sea level in MIS5, MIS3 and MIS1 phases from bottom to top. There has been differential subsidence movement in the study area since Late Pleistocene, and the differential movement has slowed down in Holocene.[Conclusion] Under the background of continuous tectonic subsidence, large-scale marine transgressions in the coastal area of Bohai Bay have all occurred since Late Pleistocene. These transgressions are related to the long-term subsidence process in the southeastern area of Tianjin along the coast of Bohai Bay, and the subsidence center moved from Bamencheng Town of Baodi District to Chadian Town of Hangu District. After entering Holocene, the tectonic activity weakened and the differential subsidence movement was not obvious. The late Quaternary stratigraphic development and depositional environment evolution in the coastal areas of Bohai Bay are controlled by sea level changes.
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Distribution of Quaternary sedimentary thickness in South China Sea and its main controlling factors
LI Xuejie, SUN Meijing, CHEN Jiale, GAO Hongfang, PENG Xuechao
DOI: 10.12029/gc20220930001
Abstract:
Abstract：This paper is the result of 1:1,000,000 marine geological survey engineering. [Objective] Quaternary sedimentary thickness can not only reflect the provenance and sedimentary characteristics, but also reflect the tectonic activity characteristics to a certain extent. [Methods] Based on a large number of single channel and multi-channel seismic data and verified by drilling holes, the Quaternary thickness map of the SCS was compiled. [Results] The thickness of quaternary sediments in the South China Sea (SCS) varies a lot, with the maximum thickness over 2000m and the minimum one close to 0. [Conclusions]Sedimentary and subsidence centers were formed in the western margin of SCS, including Yinggehai, Zhongjiannan and Wan''an sea area, which indicates that the fault zone in the western margin is still active in Quaternary period and controls the development of these subsidence centers. The development of NE trending sedimentary centers on the northwest continental slope of the South China Sea may indicate that the northwestern SCS is still dominated by extension in quaternary. The thickness of quaternary in Dongsha sea area is near 0, indicating that the area has been continuously uplifted and washed by strong current since quaternary. Therefore, the northern South China Sea shows a pattern of subsidence in thewest and uplift in the east. The relatively thicker Quaternary in the Manila Trench in the eastern margin of the SCS is mainly a result of tectonic compression resulting in sedimentary layers thicker and abundant provenance from Taiwan and the Philippines.
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Spatio-temporal evolution of land use and human activity intensity in the Tarim River Basin，Xinjiang
WANG Luchen, HAN Haihui, ZHANG Jun, HUANG Jiao, GU Xiaofan, CHANG Liang, DONG Jiaqiu, LONG Rui, WANG Qian, YANG Bingchao
DOI: 10.12029/gc20230209002
Abstract:
Abstract: [Objective] Land use/cover change (LUCC) caused by human activities is a critical part of global environmental change. LUCC in arid regions has a particularly significant impact on regional hydrology and ecology. Therefore, exploring LUCC and its response to human activities is of great significance to the sustainable development of ecology, resources and environment in the arid inland of Northwest China. [Methods] Based on the Landsat images during 1980-2-18, this paper analyzes the characteristics of land use change in nine divisions of water resources of Tarim River Basin, by the combination of land use dynamic degree, land use transfer matrix and human activity intensity degree. [Results] In the past 40 years, farmland, construction land and woodland increased by 1.58×104 km2、1.2×103 km2 and 347 km2, respectively. By comparison, grassland, unused land and water body decreased by 1.33×104 km2、0.32×104 km2 and 815 km2, respectively. The main stream of Tarim River Basin has experienced the most significant change in land use types among nine divisions of water resources, followed by Weigan, Aksu and Kashgar river basin. Since 2000, the equivalent area of construction land and human activity intensity in Tarim River Basin has increased relatively fast, especially from 2000 to 2010. [Conclusions] Human activity intensity has showed significant spatial difference among division of water resources. Socio-economic development and policy guidance are major factors leading to land use change and human activity intensity difference.
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fuxiugen, chenminghao, wangjian, weihengye, zengshengqiang, wangzhongwei, shenlijun, zhougang
DOI: 10.12029/gc20230307001
Abstract:
This paper is the result of petroleum geological survey engineering. [Objective] Effect and significance of various tectonic history on the development characteristics and spatial distribution of source rocks in the Qiangtang Basin during the Triassic-Jurassic. [Methods] In the present study, we discuss the sedimentary records of the Late Triassic tectonic inversion. [Results] The Middle Triassic sequence has typically shallowing-upward changes and a marine regression related regional uplift. However, the Early Jurassic sequence displays typically deeping-upward changes due to the tectonic subsidence and transgression. We also identify paleogeographic inversion during the Late Triassic in the Qiangtang Basin. In the northern Qiangtang depression, the pre-existing (Middle-early Late Triassic) marine depositional areas turned into terrestrial units during the Norian. In contrast, the previously (Middle Triassic) terrestrial part of the sourthern Qiangtang depression became marine units. [Conclusions] Our study suggests that the distribution of source rocks in the Qiangtang Basin was mainly controlled by the sedimentary change and paleogeographic inversion during the Late Triassic. The Late Triassic source rocks were probably related to the foreland basin and developed in the deep water area of the northern Qiangtang depression, while the coal-bearing source rocks were developed around the basin. The Early Jurassic source rocks are probably related to the passive continental margin basin and developed in the deep-water area of southern Qiangtang depression. Oil shale-bearing source rocks are well developed in the lagoon in the northern part of Southern Qiangtang depression.
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XU Lei, ZHAO Mengsheng, CHEN Weizhi, BA Yong, ZHANG Ya, HOU Qingye, LU Fangfang, QIAN Kun
DOI: 10.12029/gc20230216002
Abstract:
Abstract: This paper is the result of agricultural geological survey engineering. [Objective] A land quality geochemical survey carried out in Chuxiong area of central Yunnan Province had found a large area of zinc and copper-rich soil. The purpose of this study is to study the migration and transformation mechanism of Zn, Cu and other beneficial elements in the soil-crop system in the farming area of zinc and copper-rich red bed mountain basin in southwest China. [Methods] In this paper, the typical farming area of Yao''an in central Yunnan is selected as the research area. Based on the geochemical data of surface soil and crop seed-root soil, the main control factors affecting the absorption and enrichment of Zn and Cu in rice and corn are discussed by analyzing the content characteristics of Zn and Cu in surface soil, crop seed and root soil, and the prediction model of crop Zn and Cu bioconcentration coefficient is established. [Results] The results showed that the average Zn and Cu contents in the surface soil of Yao ''an alluvial basin are 105.40 mg/kg and 42.67 mg/kg, the proportion of zinc-rich and copper-rich land (first-class) area are 84.86% and 90.59%, the average Zn and Cu contents in rice seeds are 19.28 mg/kg and 2.92 mg/kg, the enrichment rates are 100% and 70%, and the bioconcentration coefficients are 0.20 and 0.07, the average Zn and Cu contents in corn seeds are 21.42 mg/kg and 2.06 mg/kg, the enrichment rates are 80.00% and 6.70%, and the bioconcentration coefficients are 0.20 and 0.07. [Conclusions] There are differences in factors affecting Zn and Cu enrichment in rice and corn seeds. The main factors controlling Zn bioconcentration coefficients in rice are Soil-Zn, N, TFe2O3, and the main factors controlling Cu bioconcentration coefficients in rice are Soil-Cu, OM and S. The main factors controlling Zn bioconcentration coefficients in corn are Soil-Zn, SiO2/Al2O3 and TFe2O3. The multi-linear regression equation of Zn and Cu bioconcentration coefficients of rice and corn seeds in the typical farming area of the red layer mountain basin in Yunnan was established, and the optimal model decision coefficient was greater than 0.495, the prediction effect of rice is better than corn, and the prediction effect of Zn is better than Cu. The optimal model predicted that the planting area of Zn-rich rice, copper-rich rice and zn-rich corn in Yao''an County are 72.87 km2, 70.47 km2 and 69.71 km2. Therefore, the planting structure planning of rice and corn in the study area can be optimized to serve the development of plateau characteristic agriculture and the implementation of rural revitalization strategy.
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Zhang Baomin, Tian Wei, Zhang Guotao, Liu An, Li Xubing, Zhou Peng, Li Peijun, Miao Fengbin, Li Hai
DOI: 10.12029/gc20230301002
Abstract:
[Objective]The discovery of Permian shale gas in central Hunan is helpful to reappraise the potential of shale gas resources in Xiangzhong Depression and expand the scope of Permian shale gas exploration in South China. [Methods] Based on XSD1 well deployed in Shaoyang area, central Hunan Province, this paper uses whole-section coring, gas logging and field analytical experiments to find out the distribution and gas bearing characteristics of major Permian shale formations. [Results] 88.2m of Dalong Formation siliceous shale gas was drilled in XSD1 well, with the total analytical content of 1.29-9.97m3/t, with an average of 4.85m3/t. The gas layer between mudstone and siltstone of Longtan Formation has been drilled with a total gas content of 0.57-3.42 m3/t, with an average of 1.78 m3/t. Mudstone with argillaceous siltstone gas layer is 111.6m, and the total gas content analyzed on site is 0.90-4.55m3/t, with an average of 2.01 m3/t. [Conclusions] The enrichment of Permian shale gas in this area is mainly affected by the fault sealing property, and the footwall of slip faults is the main enrichment area of shale gas. The research results have important guiding significance to the exploration and development of Permian shale gas in central Hunan area.
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Li Xin, Dong Haogang, Xie Xiang, Luo Minxuan, Wu Feng, Yang Tao, Huang Jinyan
DOI: 10.12029/gc20220918002
Abstract:
Abstract: This paper is the result of ecological geological survey. [Objective]Formation is the carrier of the geological environment. Studying the correlation between formation and ecological characteristics is helpful to correctly understand the causes of ecological problems and serve the precise restoration of the ecological environment. [Method] In this paper, Luoshan County, which has both low mountains, hills and plains, is selected as the research area. On the basis of combing the geological background and tectonic evolution characteristics of Luoshan County, 13 geological formation types are divided; Based on profile survey, data statistics, hydrological parameter test and other means, the geological characteristics of four typical geological formations were analyzed from the four aspects of rock, soil, hydrogeology and terrain slope, and the correlation between ecological characteristics and geological formations was discussed. Taking soil erosion as an example, the spatial distribution, cause analysis and restoration suggestions are carried out based on geological formation. [Results] The results show that, from the Cretaceous acid magmatic rock formation in the low mountain and hilly area to the Cretaceous continental pyroclastic rock-volcanic formation in the hilly area, the thickness of the parent material layer and soil layer has been increasing, and the content of gravel and sand has increased. Gradually less, the particle size of the soil becomes smaller, so the soil texture gradually changes from gravel soil (sandy loam), sandy loam, silty loam, and loam; the vegetation transitions from natural secondary forest to artificially planted economic forest, and the vegetation type changes from diversity It tends to be single, but the tree height and diameter at breast height are increasing; the correlation between geological formation and ecological characteristics is strong. The genetic analysis based on geological formations shows that soil erosion develops differently in different formations, among which the Cretaceous acidic magmatic rock formation is the most serious. The problem of soil erosion has a strong correlation with the terrain slope, mineral composition and grain size of rocks in different formations. [Conclusions] Using formation as a unit to analyze ecological characteristics has better pertinence and application prospects, and can more reflect the constraints of geology on ecology. The research results can provide a geological basis for accurate restoration of ecological protection and soil erosion in Luoshan County.
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jiangxin, mayiqi, tuchunlin, huangan, huyaojun, yelei, hechengzhong, Li shiyu
DOI: 10.12029/gc20230228004
Abstract:
Abstract: This paper is result of soil geological survey engineering. 【Objective】The study area is located in an important coal and agricultural production area in eastern Yunnan Province. It is of great practical significance to understand the spatial distribution characteristics, potential ecological risks and pollution sources of heavy metals in soil of coal mining area for ecological environment protection and ensure agricultural security.【Methods】497 soil samples collected in June 2017 in a typical coal mining area based on the grid placement method, and Soil pH, SOM, As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were analyzed. Pollution load index method and potential ecological risk index method were used to evaluate heavy metal pollution status and potential ecological risk. The potential sources of heavy metals were analyzed by principal component analysis and positive definite matrix factor analysis.【Results】The mean of soil pH is 5.39, mainly acidic, and the mean of SOM content is 12.00 times higher than the background value for soils in Yunnan Province. The mean and median of Cr, Cu, Cd, Ni, Zn and Hg are all higher than the soil background value of Yunnan Province, the majority of sampling points Cd, Cu, Cr, Ni content exceeds the risk screening value, accounted for 94.97%, 93.96%, 91.35%, 79.28%, and a small number of sampling points exceeds the control values for As and Cd, accounting for 0.20% and 1.41% respectively. The results of the Pollution Load Index method of evaluation show that the study area as a whole shows slight pollution. The results of the evaluation of the potential ecological risk index method show that the study area as a whole presents a medium risk. The results of the principal component analysis and the PMF model analysis show that soil heavy metals in the study area are mainly derived from the geological background, followed by agricultural activities and atmospheric deposition.【Conclusion】 The potential ecological risk of Cd and Hg in the soil of the coal mining area is high, and the soil heavy metals mainly derived from the geological background, followed by agricultural activities and atmospheric deposition. It is suggested to strengthen the monitoring and management of related polluted land, reduce the unreasonable application of farmyard manure, and strengthen the supervision of pollution from coal industry activities.
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DOI: 10.12029/gc20220724001
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【Objectives】In order to identify nitrate sources and health risks in groundwater of Cenozoic basaltic rock in Hebei province.【Methods】The basalt distribution region in Zhangbei county is selected as a typical study area. Based on hydrochemistry and isotopes data of 45 groups groundwater samples, the distribution characteristics and origin of nitrate in basalt groundwater were studied, the health risk of nitrate in groundwater was evaluated using the health risk assessment model .【Results】The results showed that the average concentration of nitrate in the groundwater of the study area was 86.08 mg?L-1, The nitrate concentration of 26.6% of the sampling sites exceeded the limit value of the III grade groundwater quality in GB/T 14848-2017《The Quality standard of Underground Water》 (20 mg?L-1);The nitrate pollution of different land use types varied greatly, and the content of nitrate in urban areas was the highest, followed by irrigated land,with forests、grasslands or dry land not exceeding the standard.The sources of nitrate in groundwater was mainly manure and domestic sewage, and the next was chemical fertilizer leaching;The health risks of nitrate exposure through skin contact among the population in the study area were at acceptable levels, while the health risk of nitrate intake from drinking water was higher, and the contribution rate of nitrate intake from drinking water accounted for 99.23% of the total risk, which was much higher than that from skin contact route.The health risks of drinking water intake and skin contact in children were significantly higher than those of adults.The health risks of groundwater nitrates to children in 75.55% of the sampling sites exceeded acceptable levels.【Conclusions】From the perspective of water supply safety, it is recommended to increase water purification equipment in high-risk areas to reduce human health risks
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Feng Weiming, Lin Jiashan, Li Rong, Zhao Zhan, PENG jun, Yu Qian, Yang Ping, Cao Junfeng, ZHAI Kun, Liu Wei, YE DIngnan
DOI: 10.12029/gc20221228001
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This paper is the result of Shale gas geological survey engineering. [Objective] Dark shales in Lower Carboniferous upper are widely distributed in the Yadu-Ziyun-Luodian aulacogen, the upper Yangtze Platform, and its thickness varies greatly. In particular, the development characteristics and hydrocarbon generation center distribution of the dark shale of the Jiusi Fr in the northwest section of the rift aulacogen are not clear. [Methods] The strata, sedimentary facies, dark shale distribution and organic geochemical characteristics of Jiusi dark shale in well GWD-2 are studied in detail by the logging, core observation, rock thin-section identification, kerogen type microscopic identification, TOC, vitrinite reflectance measurement and other experimental test data. And the following research results were obtained. [Results] First, the drilling thickness of Jiusi Fr in the well GWD-2 is 1148.67m, according to the characteristics of rock combinations, the Lower Carboniferous Jiusi Fr can be divided into two members and five sub members, Second, the dark shales are mainly distributed in the first member of Jiusi Fr, which are mainly composed of tidal flat by delta and shallow shelf facies deposits, the cumulative thickness of shale is 525m, the cumulative thickness of shale with TOC value greater than 1% is 425m. Third, The TOC value of Jiusi shale of the well is concentrated in the range of 1% ~ 2%, the type of organic matter is mainly type II2 kerogen and III kerogen, the organic matters are in the early stage of over maturity. The last, it is predicted that the subsidence center of Jiusi Fr is distributed in a long strip with NW-SE direction, and the distribution of hydrocarbon generation center is consistent with the subsidence center. The thickness of argillaceous source rock with TOC value greater than 1% can reach more than 300m. The hydrocarbon generation center has the hydrocarbon generation conditions of argillaceous source rock with huge thickness, good organic matter type and high degree of thermal evolution. [Conclusions] It is concluded that the shale of Lower Carboniferous Jiusi Fr in the hydrocarbon generation center of the northwest section of Yadu-Ziyun-Luodian aulacogen has considerable hydrocarbon generation intensity and total hydrocarbon generation, and has good natural gas exploration potential.
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Liu Yuegao, Zhang Jiangwei, Feng Zhixing, Yang ShunLong, Wang Yizhong, Li Jiqing, Zhao Zhiyi, Wang Zhian, Li Shulei, Wang Houfang
DOI: 10.12029/gc20230128003
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[Objective] To improve the supply security of Cu-Ni-Co resources in China, it is necessary to sort out the mineralization regularity and prospecting indicators of the magmatic copper-nickel-cobalt sulfide deposit in the Phanerozoic in the Eastern Kunlun orogenic belt on the northern margin of the Qinghai-Tibet Plateau. [Methods]The geological, geochronology, geochemistry, and geophysical characteristics of five stages mafic?ultramafic complexes including the Late Ordovician?Early Silurian, the Middle Silurian?Middle Devonian, the Early Carboniferous, the Middle Permian?Early Triassic, and the Middle?Late Triassic are summarized. [Results] Based on the above work, the source area properties of magmatic copper?nickel deposits and their relationship with the highpressure?ultrahighpressure eclogite and the evolution of Proto?Paleo Tethys were discussed. The influence of crustal sulfur contamination and crystal differentiation on sulfide saturation was analyzed. The rules of the optimal location of copper-nickel ore bodies were summarized. The typical differences between the ore-forming mafic-ultramafic complexes and the no-ore mafic-ultramafic complexes were described. [Conclusions] At last, a comprehensive information exploration model was established.
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WANG Renqi, TAN Keyan, SUN Qian, LI Hang, ZHANG Longlong, YUAN Xin, ZHU Xiaohua, WANG Yu, CAI Jingyi
DOI: 10.12029/gc20221228002
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【Objective】With the purpose of evaluating health risk of heavy metals in the typical Oats Production Region of Bashang area in Zhangjiakou, oats fields in Zhangbei County were selected as the research site, and atmospheric dry and wet depositions, groundwater samples, topsoils and oats point-to-point samples were systematically collected to determine health risk of heavy metals. 【Methods】Health risk assessment mode were used to evaluate non-carcinogenic and carcinogenic risks of topsoils, air depositions and groundwater samples, single target hazard quotient (THQ) and comprehensive target hazard quotient (TTHQ) were used to assess the health risk of heavy metals in oats to human health. 【Results】The result showed that carcinogenic element Cr, and non-carcinogenic elements Pb and Cu in the groundwater of study area pose health risks, with Pb being the major factor contributing to the health risk of heavy metals in groundwater. There was no non-carcinogenic health risk of heavy metals found in the atmosphere. Among the carcinogenic elements, Cr, As and Ni posed certain carcinogenic risk. There was no carcinogenic or non-carcinogenic risk of heavy metals in the soil samples of the study area; Cu, Zn and Ni in some oats seed samples exhibited health risks to both adults and children, with mean values of THQ for children being higher than 1, and THQ and TTHQ risk values were both higher in children than adults. 【Conclusion】Through the comprehensive health risk assessment of heavy metals in typical oats production region of Bashang area in Zhangjiakou, it was found that heavy metals in this area pose relatively little health risks to humans, but attention needs to be paid to their impact on children’s health, and some heavy metals need to be monitored for risk.
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BAO Shujing, GE Mingna, XU Xingyou, GUO Tianxu, LIN Yanhua, MOU Degang, LIANG Hongbo
DOI: 10.12029/gc20230105002
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【Objective】In China, shale oil resources are abundant and developing rapidly, but there are still key issues such as low exploration rate, high extraction difficulty, and low production. Therefore, it is necessary to analysis the progress and situation of the exploration and development of continental shale oil, and suggestions for the development of shale oil are put forward to serve the national energy security. 【Methods】By combing the development history of shale oil at home and abroad, this paper analyzes the direction and field of the major breakthrough and important progress of continental shale oil exploration and development in recent years, summarizes the growth points of shale oil reservest. 【Results】Eight major developments were made, mainly including the Ordos Basin proved the first one billion ton shale oil field in China, the estimated new shale oil reserves in Gulong Sag of Songliao Basin are 1.268 billion tons, A number of exploratory Wells in the Paleogene in Bohai Bay Basin have been tested to produce high industrial oil flow and the Jimsar shale oil third-level geological reserves of 500 million tons in Junggar Basin. To form the shale oil enrichment theory and exploration and development technology with Chinese characteristics. By the end of 2021, China had proven geological reserves of 1.22 billion tons of shale oil, with 27.106 million tons of unproven geological resources, representing a discovery rate of 4.3 percent and huge exploration potential. Eight large and medium-sized oil and gas basins have made major breakthroughs in the investigation and exploration of multiple layers of shale oil, which shows the broad development prospect of continental shale oil in China.【Conclusions】Ordos Basin, Bohai Bay, Songliao Basin, Junggar Basin, Sichuan Basin and Jianghan Basin are the main areas for shale oil exploration and development in the future and is expected to become a realistic replacement field for oil and gas during the 14th Five-Year Plan. The Paleogene formation in Bonan area of Jiyang depression in Bohai Bay basin, the Triassic formation in Longdong and Yishan slopes of Ordos basin, the Cretaceous formation in Gulong sag of Songliao basin, the Permian formation in Jimusar sag of the Junggar Basin, the Jurassic formation in eastern Sichuan basin, and the Paleogene formation in Qianjiang sag of Jianghan basin are favorable target areas for increasing reserves and increasing production. The dynamic evaluation of shale oil resource potential in large basins, research on shale oil theory and exploration and development technologies with different maturities, and investigation and evaluation of shale oil in small and medium-sized basins are the key directions for the next development of continental shale oil in China.
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DOI: 10.12029/gc20220805004
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[Objective]Gannan area in the upper reaches of Dongjiang River Basin is a typical water shortage area in China. The distribution of acid groundwater intensifies the lack of regional domestic water. [Methods]In this paper, Xunwu area in the upper reaches of the Dongjiang River basin is selected as the study area. Shallow groundwater is systematically collected, and the pH value, spatial distribution, hydrochemical types and action characteristics of acidic groundwater are analyzed by using hydrochemistry and mathematical statistics methods. From the point of view of material basis, circulation conditions and external factors, the causes of control of water rock action, aeration zone medium, acid rain, human action and other factors on acidic groundwater are discussed.[Results]The pH value of groundwater in the area is concentrated between 5.0 and 7.0; The spatial distribution has obvious correlation with geomorphic characteristics and circulation conditions: middle and low mountains
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LIU Lin, WANG DaZhao, CHEN AiZhang, CAI XiongWei
DOI: 10.12029/gc20221027003
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Abstract：This paper is the result of mineral exploration engineering. [Objectives] The phosphate deposits in Yichang Hubei Province are associated with rare earth elements (REY). The study of the distribution and occurrence state of the REY has great significance for the recovery and utilization of the REY .The comprehensive utilization of associated rare earth minerals will become an important source for the development and utilization of rare earth minerals in the future. [Methods] The main research object in this paper is the REY in phosphate. Based on systematic sampling, some research such as rock and ore identification, whole rock chemical analysis, X-ray diffraction analysis, scanning electron microscope observation and LA-ICP-MS test is carried out. [Results] The results show that the total amount of REY in phosphorite is 63.5×10-6～271.8×10-6. The content of REY in phosphorite varies with different strata and lithology. [Conclusions] The content of REY is obviously controlled by lithology. From dolomite → dolomitic phosphorite → dense massive phosphorite → argillaceous banded phosphorite to mudstone, the content is gradually increasing. The trace elements compositions reflect that the ancient climates of the Yichang phosphate deposits were mainly dry and hot, and the northwest ones were slightly warm and humid; Ce anomaly, V/Ni and Y/Ho ratio reflect that the EH conditions in seawater were gradually oxidized from the Ph22 to the Ph13.The content of total REY in the Yichang phosphate deposits is low, and the REY content in mudstone is higher than those in phosphate rocks, indicating that the content of adsorbed REY are higher than the isomorphic REY. Yichang possesses large amounts of REY in phosphate ore. The comprehensive recovery of rare earth elements with reasonable technology is of great significance to the rational utilization of Yichang phosphate rock resources and economic development.
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SU Dong, GONG Xulong, YANG Lei, XU Shugang, ZHANG Yan, LYU Hang, BU Jianwei, GONG Yabing, GU Chunsheng
DOI: 10.12029/gc20221019001
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Abstract：This paper is the result of hydrogeological survey engineering. [Object] Changzhou is a typical industrialized city in the Yangtze River Delta. The regional groundwater there had experienced a periodic historical process of overdrafts and prohibitions of mining, resulting in a greatly change in the groundwater dynamic field. Thus, it is necessary to conduct a further study on the renewable capacity of the groundwater of Changzhou. [Methods] Based on the analysis of the existing hydrogeology conditions, the recharge, runoff and discharge conditions of groundwater and the characteristics of groundwater ages are systematically analyzed to evaluate the renewable capacity of groundwater using isotope technology. [Results] The results showed that, 18O and D of the shallow groundwater are more abundant than the deep groundwater due to the evaporation to a certain extent. The recharge time of the deep groundwater with relatively closed storage environment is earlier than that in the shallow groundwater. The shallow groundwater, basically affected by infiltration recharge of modern water, has an active circulation zone of modern water reached to a depth of 40m. As for the ages of the deep groundwater, it varies from less than 2000 to 25000 years, indicating that it is mainly composed of ancient water. [Conclusion] The renewal rate of the shallow groundwater is generally higher than 0.1%/a, and controlled by the storage conditions, surface water recharge and human activities, etc. Weakly, the renewal rate of the deep groundwater is generally less than 0.05%/a, and controlled by the distribution of river ancient channel, exploitation and utilization of human beings, etc. These results can provide scientific basis for protection and utilization the groundwater in Changzhou and other areas in the Yangtze River Delta.
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DOI: 10.12029/gc20220615001
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[Objective] The Beijing-Tianjin-Hebei Plain is short of water resources, and the contradiction between supply and demand is very prominent. Increasing the use of unconventional water resources and forming a diversified water supply pattern is of great significance to alleviate the contradiction between supply and demand and support the socio-economic development and ecological civilization construction of the Beijing Tianjin Hebei Urban Agglomeration.[Methods] Systematically carry out classified data statistics on the development and utilization scale, water supply direction and utilization mode of unconventional water resources. Analyze their development and utilization prospects and ecological environment effects according to the planning and allocation objectives of unconventional water resources in Beijing-Tianjin-Hebei Plain. [Results] Unconventional water resources in the area include brackish water, Recycled water, desalinated seawater, rain water. The brackish water is mainly distributed in Tianjin, Cangzhou, Hengshui in the central and eastern plains, with a water supply prospect of 5.43×108m3; Recycled water is mainly used in large industrial cities such as Beijing and Tianjin, with a water supply prospect of 34.22 ×108m3; Desalinated seawater is mainly used in Tianjin and other coastal cities, with a water supply prospect of 4.19 ×108m3; The use of rain water is relatively scattered. [Conclusions] (1) There is a risk of soil salinization when brackish water is used for agricultural irrigation, so a reasonable irrigation and drainage system should be provided and water salt regulation should be strengthened. (2) The recycled water is used for ecological replenishment of rivers, the surface water is eutrophic and the groundwater is not polluted; Irrigation with recycled water in shallow groundwater buried areas will increase the risk of nitrate pollution; It is suggested that high-risk emerging pollutants be included in the monitoring system of recycled water use. (3) The concentrated brine and cooling hot water from the tail liquor of seawater desalination may change the distribution, composition and diversity of natural marine ecosystems, which should be paid attention to. (4) The use of rain water can reduce the water quality risk of sewage entering the river, but excessive use may affect the stability of the regional ecosystem. It is recommended that urban areas appropriately expand the use.
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ZHAO Yi, ZOU Sheng-zhang, SHEN Hao-yong, LAN Fu-ning, XIE Hao, LI Jun
DOI: 10.12029/gc20221025002
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Abstract: [Objective] In order to find out the sources and control factors of main ions and dissolved inorganic carbon（DIC）in karst wetland water. [Method] Groundwater and surface water samples were collected from Huixian karst wetland, and the characteristics of hydrochemistry and dissolved inorganic carbon isotope（δ13CDIC）were analyzed. [Results] The hydrochemical type of most groundwater and surface water of Huixian karst wetland is Ca-HCO3. Ca2+, Mg2+ and HCO3- are mainly from carbonate rock dissolution; NO3- mainly from agricultural fertilizer and nitrification of soil organic nitrogen; K+, Na+ and Cl- mainly from fertilizer, manure and sewage; SO42- mainly from acid rain and pyrite oxidation. DIC in wetland groundwater mainly comes from the dissolution of soil CO2 and carbonate minerals. According to the isotopic mass balance, the calculation results show that about 46% comes from soil CO2, and about 54% comes from the contribution of minerals themselves. Huixian Karst Wetland is not entirely the result of carbonate weathering under the participation of CO2. Sulfur-containing minerals, acid rain, and human activity derived H2SO4 also participate in the weathering of carbonate rocks as erosion media. In addition, the nitrification of agricultural input reduced nitrogen fertilizer cannot be ignored. Wetland surface water DIC mainly comes from groundwater. Wetland surface water δ13CDIC value is affected by photosynthesis of aquatic plants and CO2 degassing, and its composition is relatively positive compared with that of groundwater. [Conclusion] Water Chemistry and δ13CDIC can help understand the weathering and biogeochemical processes of karst wetlands, and it should also be combined with wetland hydrogeology and human activities to provide more accurate information.
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JIANG Haiyang, CAO Yanling, LIU Lian, KANG Fengxin, CUI Su, GUO Liangliang, SUN Zhe
DOI: 10.12029/gc20221104002
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[Objective] To assess deep granite type geothermal resource potential of Wendeng area in Shandong peninsula, [Methods] we established discrete fracture network model of hydraulic fracturing based on the geological data, the deep well temperature data, core physical and mechanical test results. The potential created heat reservoirs were simulated for target reservoir. According to the fracturing results, a coupled numerical model of seepage and heat transfer in fractured heat reservoir is established using TOUGH2-EOS1-MINC code. The influence of fracture spacing, well pattern and injection rate on productivity is studied. [Results] The results show that natural fractured reservoirs with stress shielding should be selected as the target reservoirs in deep geothermal exploitation. Large well spacing should be maintained, and reservoirs with overdeveloped natural fractures should not be selected. For the same heat reservoir, the variation of each performance index of five-well mode and three-well mode is similar, but their dynamic variation of productivity is different. The pressure index is more sensitive to the well pattern than the temperature index. The power generation of five-well mode is slightly higher than that of three-well mode for the same reservoir. [Conclusions] When selecting the target reservoir, the high temperature reservoir with moderate natural fractures and high stress shielding should be preferred. Meanwhile, a large amount of fracturing fluid should be injected to drive the reservoir to extend as far horizontally as possible. For the ideal large-scale heat reservoir, the five-well mode should be preferred, but its overall economic benefits should be considered.
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tongyunxiao, yangjunquan, wangxue, tankun
DOI: 10.12029/gc20221215001
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[Objective] Land subsidence is one of the main geological hazards in coal mine area, which seriously affects the sustainable development of mining economy and the safety and stability of residents'' life. It is necessary to monitor the land subsidence in the mining area quickly and efficiently. [Methods] The 31 scenes Sentinel-1 images of Datong coalfield acquired from January 2020 to December 2021 were used to monitor the land subsidence based on Small Baseline Subset InSAR (SBAS-InSAR) technology. The land subsidence rate and cumulative subsidence results of Datong coalfield were obtained. Moreover, the reliability of the monitoring results were verified using existing research results, and the spatiotemporal variation characteristics and evolution laws of subsidence were analyzed. [Results] The results show that the land subsidence in Datong coalfield is widely distributed, and the overall distribution of subsidence is basically consistent with the trend of mining management data in Datong coalfield. The subsidence is mainly distributed in the west of Nanjiao County of Datong City and the junction of Datong City, Huairen City and Shanyin County, among which the land subsidence of Tashan mine is the most serious. The subsidence characteristics of Datong coalfield mainly include the maximum subsidence rate of 168.03mm/y, the maximum cumulative subsidence amount of 329.12mm, and the total subsidence area of 270.95km2. Overall, the subsidence shows a trend of continuous increase, it takes a long time to realize the relative stability of surface activities according to the subsidence trend. [Conclusions] The study shows the feasibility of InSAR technology in subsidence monitoring in coal mine area, which can provide a new technical for mineral resources management work, and the research results can provide scientific basis for subsidence monitoring and warning, disaster prevention and control, and rational development and utilization of resources in coal mine area.
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TAI Surigala, WANG Yongliang, CHEN Guodong, liyongchun, xueyu, zhangyongjian, DU Yuchunzi, duyinlong, yangjinayu
DOI: 10.12029/gc20221025001
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[Objective] With the continuous increase of socio-economic development and urbanization rate, the ecological environment that mankind survival has been damaged and the ecological vulnerability has become more and more serious, and the ecological vulnerability evaluation has become a hot research spot for many experts and scholars. Since the industrial structure of Oroqen region changed from hunting to farming and livestock in the 20th century, the local ecological environment is facing the risk of getting fragile. In this paper, ecological vulnerability of Oroqen region in 3 phases is evaluated to provide scientific basis for local ecological environment protection and sustainable development [Methods] Taking Oroqen region in Inner Mongolia as the study area, 14 indicators of three types, such as ecological resilience, ecological sensitivity and ecological stress, were selected based on SPR model, and GIS Spatial Principal Component Analysis (SPCA) and GeoDetector were used to analyze the spatial distribution, spatial and temporal evolution and driving factors of ecological vulnerability in Oroqen region in 2000, 2010 and 2020. The spatial distribution, spatial and temporal evolution and driving factors of ecological vulnerability in Oroqen region in 2000, 2010 and 2020 were analyzed by using SPCA and GeoDetector. [Results] (1) The overall ecological vulnerability of Oroqen region is in a good-mild fragile state , the distribution area of general fragile area is about the identical in 3 years, the moderate and severe fragile areas are mainly distributed in the south of Alihe town, the south of Ulubuti town, Dayangshu town and Guli township, and there is an overall Research research deterioration trend. (2) The ecological vulnerability trend of Oroqen area is positive from 2000 to 2010, and the ecological vulnerability increases significantly from 2010 to 2020 when the ecological environment is damaged, and the area of severe ecological vulnerability appears for the first time in 2020 is 111.72km2, accounting for 0.51% of the area of the study area, and the ecological environment is severe. (3) It is mainly influenced by biological abundance (D2), landscape diversity index (D3), elevation (D5), population density (D13) and other factors in the spatial distribution of ecological vulnerability in Oroqen area, and the influencing factors present more diversified in 2020, and the two indicators of spreading index (D4) and average annual precipitation (D12) have a strong driving effect on local ecological vulnerability, with q values of [Conclusions] The ecological vulnerability of Oroqen region shows a significant feature of low in the northwest and high in the southeast in 2000, 2010 and 2020 , and the ecological environment has been developing towards good from 2000 to 2010 and deteriorating from 2010 to 2020, due to the continuous change of natural conditions and long-term influence of human activities. The ecological environment of Oroqen region is deteriorating in general.
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wanggaofeng, ligang, sunxiangdong, lihao, tianyuntao, donghanchuan, gaoyoulong, xuyouning, wanghongde, liruidong
DOI: 10.12029/gc20230220001
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Abstract: This paper is the result of mineral exploration engineering. [Objective] Gansu Province is one of the areas with high incidence of geological disasters in China. The scientific construction of a "point-surface dual control" model of geological disaster risks is the key to disaster prevention and mitigation. [Method] Taking Longlin Town as an example, on the basis of on-site refined survey and mapping, multi-phase remote sensing data modelling, indoor test and numerical simulation analysis, the paper expounds the typical urban geological disaster risk management and control technical process with six steps, including geological disaster risk identification, disaster mode research, risk analysis, vulnerability assessment, risk assessment and risk prevention and control countermeasures, and introduces the semi-quantitative risk assessment process of urban risk slope, the quantitative risk assessment method of single geological hazard based on dynamic process and the "point-surface dual control" mode of geological hazard risk have been formed. [Results] (1) The main types of geological hazards in the study area are landslide and debris flow, with a total of 71 hidden danger points of geological hazards developed, 15 of which directly threaten the safety of people''s lives and property. The three types of landslide hazard models are summarized and the geological early identification signs are established; (2) Based on the geological hazard risk zoning of different precipitation frequencies (5%, 2%, 1%), 75.23% of the regions always maintain low risk under different precipitation frequencies, 24.38% of the regional risk level increases with the reduction of precipitation frequency, and 0.39% of the regions always maintain high risk; (3) Based on the results of risk assessment, a comprehensive risk dual control proposal for disaster reduction in towns and specific disaster sites is proposed. [Conclusions] Relevant research can provide technical support for disaster prevention and mitigation, land space planning and control and use control of complex mountain towns.
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weishuaichao, Zhang Wei, Fu Yong, Liu Feng, Yuan Ruoxi, Yan Xiaoxue, Liao Yuzhong, Wang Guiling
DOI: 10.12029/gc20230214001
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【Objective】In recent years, lithium has become a key mineral in the world''s major economies, as demand has grown rapidly in the emerging and low-carbon technology industries. Especially under the "carbon peaking and carbon neutrality" goals, the demand for lithium resources is also becoming more urgent in China, but the security of lithium supply seriously restricts the development of new energy industry. At present, our lithium resources are mainly developed by the brine type and pegmatite type, but the geothermal brine type also has a certain resource potential. Therefore, it is necessary to study the distribution characteristics of lithium element in geothermal water. 【Methods】Based on the results of investigation and study of geothermal water in China by predecessors, this paper introduces and discusses the distribution characteristics of lithium content in geothermal water, influencing factors, lithium extraction technology of geothermal water and geothermal exploration technology.【Results】It analyzed the lithium content of geothermal water in the main heat storage of 30 provinces and cities, and actually calculated that the annual discharge of lithium metal in the 1989 geothermal water was 789t, and estimated that the annual discharge of lithium metal in the geothermal water was 3233t, indicating that the geothermal water lithium resources have certain potential. 【Conclusions】It is found that the main factors influencing the lithium content of geothermal water are the characteristics of surrounding rocks and thermal reservoir rocks, temperature, water-rock interaction, etc. It is also found that lithium isotopes have good potential in tracing the sources of geothermal systems, water-rock interactions, and material sources in continental areas. Lithium-rich geothermal water enrichment mechanism in China is mainly divided into the Himalayan geothermal belt type and Sichuan basin type, the former is related to the type in the crust remelting magma upwelling, while the latter is related to the dissolution and filtration of gypsum and halite in the strata. In addition, it is pointed out that the future prospecting direction of lithium-rich geothermal water in China will be concentrated in the Tibetan Plateau, Sichuan Basin, Jianghan Basin and oil (gas) field water. “Simultaneous exploration of geothermal water and lithium” and “simultaneous mining of geothermal water and lithium” to maximize the utilization of resources, and multiple geothermal exploration technologies will also contribute to the development of geothermal industry.
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danyong, yanjianfei, zhangqingyu, malong, nieguoquan, jishoacong
DOI: 10.12029/gc20220717001
Abstract:
Abstract: This paper is the result of shale gas geological survey engineering. [Object] In 2020, shale gas shows were first discovered in the Lower Cambrian Wuxun Formation on the southwestern margin of the Xuefeng uplift, but its accumulation conditions and exploration potential are unknown. [Methods] Based on field geological survey and drilling data, combined with organic geochemical analysis, a comprehensive study of the Lower Cambrian Wuxun Formation in the southwestern margin of Xuefeng was carried out. [Results] The results show that: (1) The shale of the Wuxun Formation was deposited in the carbonate outer ramp facies, which is different from the Longwangmiao Formation in central Sichuan at the same time. (2) The organic-rich shale is developed in the middle and lower parts of the Wuxun Formation, and the rock combination is calcareous carbonaceous shale intercalated with thin limestone, with a thickness of 30–80 m, and a long and narrow distribution in the northeast-southwest. (3) The average TOC content of shale organic matter is 1%, the organic matter type is I type sapropelic type, the average Ro is 2.02%, and the degree of thermal evolution is moderate.(4) The content of brittle minerals in shale ranges from 43% to 69%, with an average value of 59.2%, and the content of clay minerals ranges from 16% to 37%, with an average value of 28.2%.Therefore, shale has high siliceous content and high brittleness, which is easy for reservoir stimulation. (5) Shale is a low-porosity and low-permeability reservoir. Organic pores, intercrystalline pores, interlayer pores, and carbonate mineral dissolved pores provide storage space for shale gas enrichment, but at least four stages of structural fractures and The shale cleavage domain caused by tectonic action greatly improves the shale storage capacity. [Conclusion] Comprehensive evaluation indicators such as geochemistry, reservoir physical properties and preservation conditions suggest that the eastern flank of the Xingren syncline in the southwestern margin of Xuefeng can be a favorable area for shale gas exploration.
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Pan Zhaoshuai, Zhang Zhaozhi, Che Dong, Zhang Tao, Zhang Lanying, Yang Wei
DOI: 10.12029/gc20221113002
Abstract:
【Objective】Silver, as an important precious metal, has both industrial and financial properties and is crucial to promote national economic and social development. Therefore, it is important to analyze systematically the characteristics of silver resources and demand trends for emission reduction and resource security in China.【Methods】From the perspective of the development of the silver industry, the characteristics of the application, geology, supply and demand and market of silver are summarized in China. Based on this, according to the demand driven difference between industrial silver and non industrial silver, the demand of silver is predicted using S-curve and ARIMA models in China from 2022-2035.【Results】 Based on the resource status and demand forecast results of silver mines, the following results are obtained: (1) Silver mines have the geological characteristics of "four more and four less". It means that the total amount of resources is large and the available resources are few; more small deposits, less large deposits; more lean ore, less rich ore; more concomitant deposits, fewer independent deposits; (2) With the continuous growth of silver application field, domestic mine resources and renewable resources can not meet the demand, so it is necessary to import silver ore and other concentrates (used to produce silver by-products, such as lead concentrates, zinc concentrates, etc.) to supplement the gap; (3) From 2022 to 2035, the demand for silver in China will continue to grow, from 5800 t to 9500 t, with an average annual growth rate of about 3.7%; (4) From 2022 to 2035, the demand for industrial silver in China will grow rapidly, from 3800 t to 7000 t, with an average annual growth rate of 4.4%. Photovoltaic systems are the main field driving the growth of industrial silver demand; (5) From 2022 to 2035, the demand for non industrial silver in China will grow slowly, from 2000 t to 2500 t, with an average annual growth rate of 1.7%. 【Conclusions】Based on the above research results, in order to promote the development of the silver industry chain, the following suggestions are put forward: (1) The position and role of silver in the future national economy should be paid more attention; (2) A variety of ways should be adopted to ensure the supply capacity of silver resources; (3) The added value of industrial silver products should be improved to provide guarantee for energy transformation and high-end manufacturing by increasing technological innovation and carrying out deep processing; (4) The national and private silver reserve and security system should be established to avoid large fluctuations in silver prices.
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LiTong, YuReng’an, RONG Hui, YangTongxu, ZhuQiang, PengShenglong, TangYongxiang, SiQinghong, QuanXiaoqin
DOI: 10.12029/gc20220718001
Abstract:
Abstract: This paper is the result of mineral exploration engineering. [Objective] In recent years, the exploration of sandstone uranium ore in the north has progressed rapidly, and Baiyanhua uranium ore is a newly discovered medium-sized sandstone uranium ore source in the Chuanjing Depression of the Erlian Basin. The systematic study of sandstone uranium ore in Baiyanhua area is intended to provide some valuable references for the prediction of sandstone uranium ore search and the study of mineralization pattern in Chuanjing Depression of Erlian Basin. [Methods] Based on drilling data compilation, map compilation study, systematic sampling, microscopic analysis, and geochemical data compilation, the author elaborates the geological conditions of ore formation, ore body distribution, ore characteristics, and the tectonics, sedimentary filling, and fluid action of Chuanjing Depression in the mining area, and discusses the sandstone type uranium ore formation pattern in this area. [Results]The main ore-bearing level in the study area is the upper section of the Lower Cretaceous Saihan Formation, and the ore bodies are relatively gently spreading in the east and high west. The uranium minerals are mainly uraninite, mainly in gray and dark gray-black sand conglomerates. In the region, the braided river-delta system is mainly developed, the sand bodies are widely distributed and well connected, and the redox zone is developed in the center of the river, which provides favorable conditions for regional mineralization by mineralizing fluids and reducing gas transport and uranium source material transport. [Conclusion] The mineralization pattern of uranium ore in Baiyanhua area is that the uranium-rich fluids from the Baiyanhua Bulge occurred at the end of sedimentary interruption in the upper part of the Lower Cretaceous Saihantala Formation, and the uranium ore bodies were formed by diving and infiltration of uranium-rich fluids from the Baiyanhua Bulge, and the Baiyanhua Bulge was covered by sediments after the deposition of the Erlian Formation, and interstratified oxidation mineralization occurred in due course.
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liupengfei, zhangguanghui, cuishangjin, niezhenlong, caole, cuihaohao, wangqian
DOI: 10.12029/gc20220401007
Abstract:
Abstract：【Obiective】The object of the study is focusing on the characteristics and dynamic mechanism of the same variation of surface soil water and its salt in different seasons in groundwater level depth area of the northwest inland basin.【Methods】Based on data obtained from the in situ multi-factor high frequency monitoring system in groundwater regulation field site, changing processes of topsoil moisture content, pore water electronic conductivity (ECp), groundwater level depth and so on without the direct influence of precipitation and irrigation infiltration were comprehensively analyzed and studied.【Results】20 cm (shallow part)and 40 cm (deep part) depth soil moisture content in later spring，summer and early autumn were all arranged in descending order. However, the shallow and deep part soil ECp were all arranged in increasing order. The shallow part soil electronic conductivity of saturated leach solution (ECe) was arranged in descending order and the deep part soil ECe was arranged in increasing order. In later spring day variation trends of soil moisture content, ECp and ECe were the same in shallow part , which were different in the deep part soil. In summer day variation trends of shallow part soil moisture content and ECe were the same and that of soil ECp was different from them. However, day variation trends of deep part soil ECp and ECe were the same and that of soil moisture content was different from them. In early autumn day variation trends of soil moisture content, ECp and ECe were all different in shallow and deep part. 【Conclusions】Irrigation is the leading factor of influencing differences of surface soil moisture content and salt among seasons. Evapotranspiration is the major factor of resulting in changes of surface soil moisture content and salt in each season. Moreover, the higher the temperature, the more obvious the effect of the evapotranspiration. Groundwater level depth is an important and regulatory factor of affecting topsoil moisture content and salt. In summer when the groundwater level depth becomes bigger, topsoil salt content obviously decreases. In the study area the critical groundwater level depth of prevention and control of farmland salinization is between 1.6 m and 1.9 m in summer.
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liuhan, sun xianfeng, guo jing, zhang shizhen, gou zhengbin, zhang yujie, li jun, wang baodi
DOI: 10.12029/gc20220825004
Abstract:
Abstract: This paper is the result of basic geological survey engineering. [Objective] Jilong Valley will be an important area for major engineering projects across the Himalayas in Tibet in the future for a long time. However, we still lack a systematic understanding of the basic geological characteristics, especially the N-S-trending structure, which may induce unexpected engineering construction risks. [Methods] Field geological survey, joint statistics, geothermal investigation, audio frequency magnetotelluric sounding and calcite U-series dating were conducted to reveal the characteristics of the N-S-trending faults and joints in Jilong Valley, and through this to explore the main engineering geological risks related to the N-S-trending structures. [Results] The N-S-trending faults in Jilong Valley are generally small in scale, partially cutting through the high Himalayan belt, and also the basin controlling faults of Jilong Basin. The formation and sedimentary evolution of Jilong Basin were controlled by the four N-S-trending normal faluts in its east boundary and interior. The seismic rocks near the east boundary faults and syn-sedimentary faults in the basin indicate that the Jilong basin has intermittent activity characteristics. The regional permeable distribution is displayed by the N-S-trending joints, which were formed in a simialr stress field controlled by the N-S-trending rift. [Conclusions] The N-S-trending structure in Jilong Valley are potential engineering geological risk sources, according to its Holocene activity and its control over regional geothermal, and collapse, landslide, debris flow geological disasters. We propose that the North-South structure will be one of the important directions of geological safety risk assessment for the planning and construction of Jilong Valley major engineering project.
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DOI: 10.12029/gc20230413003
Abstract:
With the investment of social funds, exploration work was invested in the Qiyi Mountain Tungsten-molybdenum polymetallic Mine in Erjina Banner. 38 fluorite ore bodies were newly delineated, and the amount of resources was estimated to reach 2.214 million tons, which reached a large scale. The age of rock formation and mineralization was studied, the mechanism of mineralization was analyzed, and the prospecting signs were summarized.
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Meng Wuyi, GAO Yongbao, WEI Liyong, ZHANG Zhen, JIA Bin, Zheng Xin
DOI: 10.12029/gc20230327003
Abstract:
Xi"an Center of Mineral Resources Survey, China Geological Survey，relying on the "Geological Survey of Lead and Zinc Minerals in the Xunyang Zhenping Area, Shaanxi Province" project, conducted a survey of polymetallic minerals, mainly gold and antimony, in the Zhenxun Basin, South Qinling. From 2020-2022, mineral geological surveys were conducted on five standard maps in the area of Xiaohekou to Shuanghekou, and micro disseminated gold deposits controlled by interlayer fracture zones were newly discovered in the Tieshan Formation strata in the area, through drilling engineering control, it is inferred that the gold resource is 2.57 tons, and the prospective resource has a large scale. The discovery of Wangzhuang gold deposit is of great significance for expanding the ore-bearing horizon and gold deposit status of fine disseminated gold deposits in the southern Qinling.
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LIU Tianhang, GAO Yongbao, LIU Jiajun, WEI Liyong, TANG Weidong, LI Zonghui, HE Jiale, LI Jiawei
DOI: 10.12029/gc20220816002
Abstract:
Abstract: This paper is the result of mineral exploration engineering. [Objective] The Dongqiyishan fluorite deposit is a super-large fluorite deposit, which is related to alkali feldspar granite in the eastern part of the Beishan metallogenic belt. The orebodies are hosted in alkali feldspar granite, griotte and andesite, which are controlled by the rupture and fracture zones near SN or NE dipping. [Methods] On the basis of studying the geological characteristics of Dongqiyishan fluorite deposit, carry out the studies of rare earth and trace elements geochemistry of fluorite and wall rocks in the fluorite deposit. [Results] The results show that the trace elements curves in fluorites are consistent, and obviously enriched in high-temperature elements such as Bi, Cd and Mo relative to the crust values, indicating that these fluorite samples have the characteristics of high temperature mineralization and homology. Fluorites and alkali feldspar granites have similar geochemical characteristics of rare earth. The Y/Ho ratios of 10 fluorite samples are ranging from 21.02 to 28.52, the La/Ho ratios ranging from 3.58 to 15.23. The samples all falling into the hydrothermal region of Tb/La-Tb/Ca diagram, except one close to the sedimentary. The Sm/Nd ratios of fluorites ranging from 0.26 to 0.42, and the Sm/Nd ratios of alkali feldspar granites ranging from 0.26 to 0.42. The δEu vaule ranging from 0.6 to 0.64, and the δCe vaule ranging from 0.89 to 0.94. [Conclusions] Combined with the geological characteristics of the deposit, It is considered the genetic type of the deposit is medium-high temperature magmatic hydrothermal filled type, which belongs to the tungsten-tin-rare -fluorite metallogenic system related to alkali feldspar granite in the area. The ore-forming fluid of Dongqiyishan fluorite deposit is mainly magmatic hydrothermal. The ore-forming material F mainly comes from the deep alkali feldspar granite body, and the Ca mainly comes from the marble strata.
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LIU Haiqing, JIN Pengbo, Liu jingdong, Liu Hua, ZOU Juan, Chen lei
DOI: 10.12029/gc20220910001
Abstract:
[Objective] The superimposed development of multistage faults is very important to the difference of hydrocarbon migration and accumulation in faulted basins. [Methods] Taking Laoyemiao structural belt in Nanpu Depression, Bohai Bay Basin as an example, the fault assemblage style and its origin, the relationship between fault system and oil and gas reservoir formation were studied based on geological analysis and physical simulation experiment. [Results] The results show that Laoyemiao structural belt developed fault combinations of "ladder" type, "domino" type, compound "y" type, compound anti "y" type. The formation of fault combinations is closely related to the boundary of the fault activity, in which "ladder" type and "domino" type fault combinations formed by the northwest - southeast and nearly north – south direction stress fields in Paleogene, while compound "y" type and anti "y" type fault combinations formed because of late superposition of fracture in Minghuazhen period. The discrete element numerical simulation results show that the existence of large plastic mudstone layers in Dongying Formation is the key material factor leading to the difference of deep and shallow deformation and vertical superposition. [Conclusions] Multistage fault superimposition plays an important role in controlling hydrocarbon accumulation: early faults control depressions and structural belts, late faults control traps and hydrocarbon accumulation, and fault assemblages affect hydrocarbon enrichment strata.
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LI Fulin, DUAN Qifa, SHI Deqiang, WANG Chenggang, LI Qiang, WU Fafu, ZHOU Hanwen, CHENG Shunbo
DOI: 10.12029/gc20230309003
Abstract:
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Zhao Yan, Guo Changlai, Cui Jian
DOI: 10.12029/gc20220829001
Abstract:
【Objective】Find out the distribution characteristics of heavy metals and provide scientific basis for local characteristic agricultural development, global tourism and soil heavy metal pollution control.【Method】Through Geological Investigation, soil parent material is identified, topsoil samples are collected, soil environmental quality evaluation was carried out on the basis of the distribution characteristics and enrichment degree of element content , the degree of heavy metal pollution was evaluated by using the ground accumulation index method., the Hakanson ecological risk index method was used to identify the degree of potential ecological risk in the study area, and further by pearson correlation analysis and cluster analysis to quantitatively determining main sources of different heavy metals.【Results】The results showed that the average value of Cr and Pb in the soil of Beizhen agricultural area was lower than the background value of Liaohe River Basin in Liaoning Province. The enrichment degree of heavy metals in topsoil rangs from large to small was Hg>As>Cd>Pb>Zn>Cu>Cr>Ni.The soil quality in the study area is generally good. The proportion of Cd, Cu and Zn contents exceeding the risk screening values in the exceeding standard samples is 45.56%, 29.11% and 11.47% respectively, accounting for 86.12% of the total number of exceeding standards; The evaluation results of heavy metal pollution showed that As and Cd are in a mildly polluted state, most heavy metals in soil samples were in no to mild pollution, and only Hg elements have strong to extremely strong pollution.The order of potential ecological risk of single index from high to low is Hg>Cd>As>Cu>Ni>Pb>Cr>Zn. The distribution range of potential ecological risk comprehensive index RI of surface soil in the whole region is 29.7 ~ 2358.16, with an average value of 141.9, mainly with low risk, followed by moderate risk.The results of correlation analysis and cluster analysis show that Ni, Cr, As and Pb are mainly affected by the natural source of natural weathering of the parent rock, and Cu, Zn, Cd and Hg are affected by agricultural production, industrial production, transportation, and even construction activities.【Conclusions】The enrichment of substances produced by the unreasonable application of agricultural substances, atmospheric deposition, industrial production, domestic garbage and coal combustion in the soil may cause pollution risks to the ecological environment quality of the study area. In the future, it is necessary to strengthen the monitoring and research on the enrichment trend of Hg, Cd, Cu and Zn elements in different plots.
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LIUZHIBO, TANG JUXING, LI ZHIJUN, WANG NAN, YU JIE, DUAN YI, CHEN WEI, YANG GONGMING, QI HUI
DOI: 10.12029/gc20220928003
Abstract:
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Dai Jianling, Lei Mingtang, Jiang Xiaozhen, WanFang Zhou, Meng Yan, Wu Yuanbin, Guang Zhende, Jia Long, Yin Renchao, Pan Zongyuan, Yin Ou, Chen Yingzi, Yang Tao, Lei Zhuping, Huang Jingjun, Yang Rongkang
DOI: 10.12029/gc20220819001
Abstract:
[Objective] Karst collapse is one of the main environmental geological problems in the Yangtze River Economic Zone. The study on the distribution and causes of karst collapse in the Yangtze River Economic Zone and its impact on engineering construction is of great significance to the geological environment security guarantee of the construction of three-dimensional comprehensive transportation corridor and the new urbanization construction in the Yangtze River Economic Zone. [Methods] This paper systematically combs the research results of karst collapse in the Yangtze River Economic Zone, and discusses the characteristics of karst environment, the causes and mechanisms of karst collapse, the development and distribution laws, the impact on engineering construction, and the prevention and control measures. [Results] The research results show that the area prone to karst collapse in the Yangtze River economic zone is about 254000 square kilometers, and there are 2146 recorded karst collapse disasters. Mine drainage, water pumping, engineering construction are the main inducing factors of karst collapse in this area. The karst collapse in the Yangtze River economic zone has the following development and distribution laws: first, it has regional and zonal distribution characteristics; Second, the developed strata are generally uniform pure carbonate rocks, which are distributed along the fracture zone, fracture development zone of fold axis, contact zone of soluble rock and non-soluble rock and other karst cave fissure dense development zones; Third, it mostly occurs in the strong runoff zone of karst groundwater, the river banks and other sections where the groundwater level changes greatly and the hydrodynamic conditions are prone to rapid changes; Fourth, most of them occur in areas with strong human engineering activities. The scale of collapse depends on the nature and intensity of human activities. In order to reduce the impact of karst collapse on project construction and safe operation, this paper also puts forward relevant suggestions and countermeasures. [Conclusions] Karst collapse in the Yangtze River Economic Zone is widely distributed and harmful. The planning and construction of linear projects and important urban agglomerations in high risk areas should pay attention to this environmental geological problem. The research results can provide basic support and theoretical basis for land space planning and geological disaster prevention in the Yangtze River Economic Zone.
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ZHEN Shi-jun, ZHAO Jia-yi, ZHANG Cui-yun, YIN Mi-ying, ZHANG Sheng
DOI: 10.12029/gc20220830002
Abstract:
[Objective] Understanding the diversity of methanogenic communities in the deep environment is the basis for exploring the origin of early life, extreme environmental life and regulating methane production. However, the diversity of methanogenic communities in the deep carbonate karst-fracture geothermal water is still unclear. [Methods] The deep geothermal water samples were collected for methanogenic marker gene mcrA-based high-throughput sequencing by the pumping tests performed in the geothermal scientific drilling holes located in the Jizhong geothermal area, China to explore the diversity of methanogenic communities in the deep carbonate rock karst-fracture geothermal water. [Results] Results showed that 3 classes, 4 orders and 8 genera of methanogenic communities were detected in the deep geothermal water, of which Methanothermobacter, belonging to Euryarchaeota, Methanobacteria and Methanobacteriales, was dominant methanogens, accounting for 99.85% of the total sequences. The dominant species based on mcrA was closely affiliated with Methanothermobacter wolfeii (similarity 99%, accounting for 71%). The metabolic pathway of methanogens was mainly the pathway of CO2 reduction. The compositions of methanogenic communities in different samples were different, but Methanothermobacter was a dominant genus in all of the samples, accounting for more than 99.77%. [Conclusions] This study reveals that the deep geothermal water from the carbonate rock karst-fracture geothermal reservoirs contains relatively abundant but extremely uneven compositions of methanogenic communities and expands the habitat type of Methanothermobacter, which provides scientific basis for further studying the function of methanogens in the earth ecosystem.
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Guo Hui, Zhao Hongge, Chen Jiangmeng, Shao Xiaozhou, Liu Chiyang, Wang Jianqiang, Lei linlin, LiJun, WANG Jian, Huang Lei
DOI: 10.12029/gc20210802002
Abstract:
【Objective】The Triassic Yanchang Formation in Gufengzhuang area belongs to the low permeability reservoir with natural fractures, but in the past, there were few studies on its fracture characteristics. Therefore, it is of great significance for the exploration and development of low permeability reservoirs to study the characteristics and formation period of natural fractures.【Methods】In this paper, by means of outcrop, core, imaging logging, scanning electron microscope, fluid inclusion, fault activity and tectonic stress, the characteristics, formation stages and causes of natural fractures in Yanchang Formation in Gufengzhuang area are studied, and the influence of fractures on low permeability reservoirs is discussed.【Results】The research shows that natural fractures are all developed in each Member of Yanchang Formation, with Chang 7 being the most developed Member, followed by Chang 8 and Chang 6 Members. The fracture strike is mainly in NEE direction, followed by NE direction, and a few NW and NWW directions. Calcite filling and obvious oil marks can be seen on the surface of the crack. Natural fractures are closely related to the thickness of rock strata, fault activity and so on. Comprehensive analysis of fracture inclusions, faults and tectonic activities shows that the formation period of fractures is multi-stage, mainly in Yanshanian and Himalayan periods.【Conclusions】The development of natural fractures has improved the porosity and permeability and reservoir space of low-permeability reservoirs in the study area, and provided favorable conditions for the near source, short-distance migration, reservoir accumulation and enrichment of low-permeability reservoirs. The development degree and formation period of natural fractures affect the reservoir formation and productivity of low-permeability reservoirs.
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WANG Lei, DUAN Xingxing, ZHAO Yu, LI Wenming
DOI: 10.12029/gc20220906001
Abstract:
【objective]】The mining industry in the Baiyin region of Gansu Province is well-developed, leading to severe heavy metal soil contamination. Grasping the influence of heavy metal contamination of the soil and its potential risks to ecological health is significant in protecting the environment.【Methods】Taking the surface soils in the four-dragon town-north bay town farmland area of Baiyin region of Gansu Province as the research object, four methods, namely the single-factor index, Nemerow comprehensive index (PZ), geochemical accumulation index, and potential ecological risk index (RI), were used to analyze and evaluate the heavy metal (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) contamination in the region.【Results】The single-factor index results showed that the soil pollution in the study area was mainly Cd and As, in which the levels of PCd were at first-class cleanliness (89.21%), slight second-class pollution (8.63%), third-class light pollution (0.72%), fourth-class medium pollution (1.44%), and the levels of PAs was at first-class cleanliness (94.24%), slight second-class pollution (5.04%), fourth-class medium pollution (0.72%). PZ ranged from 0.339 to 2.869, with an average of 0.603, indicating that 85.61% of the soil was clean, 7.91% was slightly polluted, 5.04% was lightly polluted, and 1.44% was moderately polluted. The geochemical accumulation index results showed that the heavy metal contamination of the soil in the study area was generally at the level of 0-2, mainly Cd, Hg, As, and Pb. In the potential ecological risk area, Cd and Hg were the main pollution factors. Cd had the highest potential ecological risk, with 10.07% belonging to medium potential risk, 5.04% to relatively high potential risk, and 1.44% to very high potential risk. The average value of the RI was 211.80, indicating that the soil in the area was generally at a medium danger level. The four evaluation methods were consistent overall, indicating that the study area was mainly contaminated by Cd, As, and Hg and should be strengthened for monitoring.【Conclusion】Through the divisional study of the survey area with the Yellow River as the boundary, the results showed that the soil of the north bank of the irrigation and silt area (Area B) was the most polluted, and the pollution level was the highest at the junction of East Dagou River. The heavy metal analysis results of the water and sediment samples also confirmed that the pollution of East Dagou River was more obvious, further confirming that the north of the study area was mainly polluted by the East Dagou River basin of Baiyin mine, while the soil on the south bank of the Yellow River was relatively clean, but was still affected to a certain extent. In recent years, soil pollution has been alleviated to some extent with the measures of Yellow River irrigation and mining environmental governance. However, the heavy metals accumulated in the soil need long-term natural degradation or migration, and monitoring and governance should be strengthened for the high-risk areas.
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wangfugui, Xia Falai, Xu Yongli
DOI: 10.12029/gc20230310003
Abstract:
There are many Mafic - ultramafic rock masses distributed in the Beishanbei belt of East Tianshan-Gansu Province, which are jointly controlled by Kangguel-Huangshan fault. It has been proved that this belt is an important origin of magmatic Cu-Ni- (PGE) sulfide deposit with favorable regional metallogenic geological conditions. The Third Exploration Institute of Gansu Provincial Bureau of Geology and Mineral Resources, through the implementation of the provincial geological exploration fund project, discovered for the first time a small magmatic melting type Cu-Ni deposit in the Beishan North Belt. The ore form is complex, the deep mineralization needs to be further verified, and it has the potential to become a medium Cu-Ni sulfide deposit. The discovery of this deposit is of great significance to expand the prospecting idea and direction of the Cu-Ni deposit in the Beishan North Belt.
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DOI: 10.12029/gc20230222001
Abstract:
Abstract: This paper is the thinking and discussion on problems of geological survey of coal measures gas. [Objective] The concept renewal drives the new geological survey plan of coal measures gas (CMG), and the new plan drives the breakthrough of geological survey of CMG. [Methods] Review the geological survey process of CMG, differentiate the basic concept of CMG, summarize the key progress of CMG research and exploration, and then put forward suggestions for CMG geological survey. [Results] (1) The geological survey of CMG in China has gone through four stages, there is no comprehensive and systematic understanding of CMG resources so far, and it is imperative to find out the situation through geological survey. (2) Five basic concepts of CMG are identified and analyzed to provide reference for accurately defining boundary conditions of geological survey. (3) Four key advances in the research and exploration of CMG are summarized, providing reference for the selection of geological survey basis. (4) Five principled suggestions for geological survey are put forward to provide reference for determining the key points of geological survey. [Conclusions] The geological conditions of CMG are distinctive, and the geological survey plan strives to be targeted. The geological survey of shallow CMG mainly focuses on verification, while the deep CMG resource is the top priority of the survey. It is suggested to investigate the potential of deep coalbed methane resources and its scale release value, and establish a prediction and evaluation model for key attributes of deep coal reservoirs. The traditional constraints on the thickness of a single reservoir need to be broken, and attention should be paid to the ultra-large scale accumulation and high permeability conditions focusing on thin-interbed CMG. The gas volume test procedures and methods of coal measures reservoirs need to be improved, and the application scope of high reliability calibration method should be expanded to promote the geological survey of CMG to close to the development effect. The potential of CMG in some basins that have previously "leaked" should be paid attention to, and the potential of deep basins and basins with poor coal-bearing property should be investigated.
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zhou yin zhu, ma tao, yuan lei, li fu cheng, wu xi, han shuang bao
DOI: 10.12029/gc20220401003
Abstract:
【Objective】The Beiluo River Basin is an important secondary tributary of the Yellow River. Research on groundwater quality in typical tributary basin of the Yellow River is of significant for ecological protection and high-quality development. To ensure local drinking water safety, we systematically identified status of groundwater quality and delineated inferior groundwater region in the Beiluo River Basin. 【Methods】Besides, based on analysis of D-18O isotope in groundwater, characteristics and evolution mechanism of groundwater hydrochemistry were studied and effects of hydrogeological condition and anthropogenic activities on groundwater hydrochemistry were revealed. 【Results】 Results showed that groundwater hydrochemical composition was jointly affected by rock weathering and evaporation concentration, part of which was influenced by anthropogenic activities. D-18O isotope composition suggested that evaporation concentration is the major influence factor of groundwater hydrogeochemistry. 【Conclusions】Leaching of soluble minerals such as gypsum halite in clasolite and evaporation concentration of pore water in Cenozoic faulted basin in the downstream caused salt accumulation and high TDS in groundwater in the upstream and downstream, respectively. Hydrochemical composition of groundwater in Ordovician karst aquifer and Cenozoic faulted basin aquifer was mainly controlled by evaporites and anthropogenic activities. While hydrochemical composition in Cretaceous aquifer and Carboniferous-Jurassic aquifer was mainly controlled by rock weathering (especially silicate rocks and evaporite) and less affected by anthropogenic activities. Moreover, groundwater in the upstream and downstream was significantly affected by industrial and mining activities. While groundwater in the midstream is of good quality due to less influence of industrial/mining activities, agricultural activities and domestic wastewater.
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matao, Li Wenli, hanshuangbao, Zhang Hongqiang, Wang Wenke, lifucheng, lihaixue, He Xubo, Zhao Meimei
DOI: 10.12029/gc20220401001
Abstract:
[Objective] Shaanxi Province is an important province through which the Yellow River flows. Revealing groundwater resource endowment, exploring distribution characteristics, influencing factors and exploitation and utilization potential of groundwater resources can provide important support for ecological protection and high-quality development of the Yellow River Basin.[Methods] Taking Shaanxi Province of Yellow River Basin as the study area, the groundwater resources are evaluated by dividing evaluation units. The Thiel index is introduced to assess differences in the distribution of groundwater resources by region in terms of both population and area. Grey correlation analysis is used to explore the influencing factors and degree of groundwater resource distribution. The exploitation and utilization degree and potential of groundwater resources in each administrative region are evaluated quantitatively by means of water resource load index and exploitation potential index. [Results] The annual average groundwater resource in the Yellow River Basin of Shaanxi Province is 77.59×108m3/a. The regional distribution of groundwater resources varies greatly. The population and area distribution of groundwater resources in GuanZhong basin area of each evaluation unit has the largest difference, and the difference of groundwater resources distribution between Yan ""an City and Xi ""an City is the largest. Precipitation is the most important factor affecting groundwater resources in the whole region, followed by human activities, especially agricultural irrigation. Surface water factors have a great impact on Weinan and Yulin cities, and evapotranspiration has a certain impact on groundwater resources in Yan ""an, Yulin and Baoji. The groundwater exploitation potential index of the study area is between 0.8-2.5, and the groundwater resource load index shows an upward trend, which is a high load area compared with the whole country. The spatial difference of development and utilization potential of each administrative region is obvious. The region with high development degree is concentrated in Guanzhong City group. Xi ""an City has the highest development degree and Tongchuan City has the lowest development and utilization degree.[Conclusions] The distribution of groundwater resources and development potential in the Yellow River Basin of Shaanxi Province is very different, and the influencing factors are multiple. Therefore, it is necessary to further strengthen the optimal allocation of water resources, zoning and classification regulation, and build a more coordinated pattern of resource development.
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LIjianfeng, Fenglixiao, Chenxiqing, Fujianming, Luyouyue
DOI: 10.12029/gc20220825003
Abstract:
[Objective] In this paper, the status and risk of heavy metal pollution in the soil around the tin mining area was determined by 7 heavy metal elements such as Cu, Pb, Zn, Cr, Cd, As and Hg of 114 pieces of surface soil and 3 groups of column soil. [Methods] the pollution level, potential ecological risk and human health risk in the area was evaluated via the Geo-accumulation index method, potential ecological risk index method and health risk assessment model. [Results] The average content of soil heavy metals in the study area manifested that As > Zn > Pb > Cu > Cr > Cd > Hg. In terms of spatial distribution, the Cu, Pb, Zn, Cd and As elements concentrated near the mine area and their contents decrease with increasing depth and tend to be stable below 60cm. The Cr element is mainly distributed in congested area. The Hg element is uniformly distributed. The results of the cumulative land show that the As and Cd elements are heavy level polluted, and the Cu, Pb and Zn elements are lightly-heavy level polluted, and the Cr and Hg elements show no-light level pollution in the study area. Potential ecological results show that the study area is at heavy pollution levels, with the most severe ecological risks of As and Cd elements. Health risk assessment shows that the As and Pb elements in soil are the main non-carcinogenic factors and the As element is the main carcinogenic factor. The As element is the main risk of non-carcinogenic and carcinogenicity. The oral ingestion is the main route of exposure, and children are more vulnerable to heavy metal pollution. [Conclusion] To some extent, all seven heavy metals in the study area were affected by anthropogenic factors. The As and Cd elements are the most influenced by humans, and the Pb, Zn and Cu followed. The Cr and Hg elements were weakly affected by humans.
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Wu Shanshan, Yao Weijun, Zhou Juan, Jia Zhijie, Wang Dan, Zhu Peng, Yang Binbin
DOI: 10.12029/gc20220706002
Abstract:
This paper is the result of geothermal geothermal geological survey engineering. [Objective]Dafeng District，located in the northern part of Yancheng City，Jiangsu Province，is an area with abundant geothermal resources. It is of great practical significance to systematically study the characteristics of geothermal resources for the potential of coal and emissions reduction in the development and proper utilization of local geothermal resources. This is to strive for the strategic goal of achieving peak carbon dioxide emissions as soon as possible. [Methods]By comparing and analyzing the "heat source， channel， reservoir，and cap" of geothermal geological conditions for three typical geothermal wells in Hengbei Village，Holland Flower Sea Geothermal Well，and Milu Town Geothermal Well in Dafeng District，the characteristics of geothermal resources in Dafeng District were studied and summarized. [Results]Through the evaluation of water quality and theoretical calculations of mineable and reserve amounts of geothermal wells in this area，we surmised that the geothermal well development and utilization in this area is mainly towards physical therapy，bathing，and heating. The theoretical total coal-saving amount that can be achieved through the exploitation of the geothermal resources in the three wells is 8，884 tons per year， and the corresponding CO2 emissions reduction is 21，197 tons per year. The theoretical total coal-saving amount that can be achieved through the storage of geothermal water in the resources reserved area of the three geothermal wells in Hengbei Village，Holland Flower Sea Geothermal Well，and Milu Town is 18，885，886 tons，corresponding to a CO2 emissions reduction of 45，061，725 tons. [Conclusions]The results of this study provide basic evidence or references for the exploration and development of geothermal resources and the analysis of carbon emissions reduction potential in the Dafeng District.
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DOI: 10.12029/gc20221025004
Abstract:
[Objective] Through studying the content and spatial distribution characteristics of heavy metals in the surface soil of Yuanzhou District, Guyuan City, Ningxia, the ecological risk of this area was evaluated, and the accumulation of heavy metals in the surface soil of Yuanzhou District was clarified. [Methods] A total of 12,988 soil samples were collected and tested for the concentration of eight heavy metals, namely As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. The single-factor index, Nemerow comprehensive pollution index, and potential ecological hazard index methods were employed to estimate the ecological risks associated with heavy metal contamination in soils. [Results] Compared to the background values of Ningxia Autonomous Region, the average enrichment coefficients of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were 1.01, 1.42, 1.04, 0.99, 1.03, 0.81, 1.01, and 1.07, respectively. We observed similar distributions of the eight heavy metals, with high concentration values primarily found in areas with frequent human activities, such as the east and west sides of Liupan Mountain, Guyuan City, Zhangyi Town, and Huangduobao Town. In contrast, low concentration values were observed in Tanshan Township and Zhaike Township in the northeast Quaternary areas with loess-covered soil. The single-factor index evaluation revealed that the soil was "clean" in the Yuanzhou area. The Nemerow comprehensive pollution index evaluation indicated that the soil pollution index of all heavy metals was less than 0.7, which is considered "clean." While the single-element potential hazard index of Cd and Hg reached moderate risk levels, the comprehensive potential ecological hazard index of heavy metals was at a slight risk level.[Conclusion] Overall, the soil quality in Yuanzhou District, Guyuan City is in good condition, but heavy metals were slightly enriched in the topsoil due to human activities in some areas.
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DOI: 10.12029/gc20220812001
Abstract:
[Objective] A systematic review has been performed on groundwater investigation and research in the Taklimakan desert in recent 60 years, in order to summarize major achievements and understandings on groundwater recharge, discharge and circulation. The main shortcomings of current investigation and research as well as ten open questions were put forward and further study areas were pointed out. [Methods] Investigation reports and academic papers were systematically collected on groundwater in the Taklimakan desert for a comprehensive review on groundwater quality, quantity and circulation, in a combination with latest relevant achievements on desert groundwater from domestic and international hydrogeological communities.[Results] Groundwater in the desert originates from lateral groundwater flow from oases, precipitation and river water infiltration and groundwater is mainly consumed by evapotranspiration as well as a limited amount of human withdrawal. Groundwater storage is vast and at a level of 80 trillion m3. Currently, there is a great uncertainty in groundwater recharge and discharge estimation. Groundwater quality is poor in general as indicated by the total dissolved solids (TDS) spatial distribution where the majority of the desert has saline groundwater with TDS ranging from 5 to 10g/L, while only a small area with TDS less than 5 g/L. Vertically, groundwater quality is characterized by saline groundwater in deep and brackish groundwater in upper layers. Groundwater flows northward regionally and turns to flow eastward at the northern margin of the Tarim river fluvial plain, with a mean velocity of 55.94 m/a.[Conclusions] To solve these scientific question, in the future groundwater recharge and discharge should be quantified with more quantitative ways and longer time frame. Detailed data on groundwater circulation should be collected through the packer tests and monitoring in order to systematically study groundwater circulation patterns, put forward regional groundwater flow patterns and summarize quantitatively the features of each flow system. Identification of fresh water and techniques for utilizing high TDS groundwater in the desert should also be enhanced in the future investigation and research.
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SUN Jie, CHENG Aiguo, Liu Kang, ZHANG Li, ZHAO Xin
DOI: 10.12029/gc20221122001
Abstract:
[Objective] Coal is the main energy source in China. Coalbed methane is one of important and dangerous fountainheads of coal mine production process and also an important clean energy. The main component of coalbed methane is methane, the greenhouse effect of methane is 80-120 times as the same volume of carbon dioxide. Massive emission of methane will seriously affect the quality of environment. Through analyzing the coordinated exploration of coal and coalbed methane patterns and technologies in China, this paper proves the necessity and flexibility of the coordinated exploration of coal and coalbed methane. After that, new technical approach to the cooperative exploration of coal and coalbed methane in China was proposed. [Methods] Based on the relative documents and literature, This paper analyzes and discusses the energy supply and demand, current situation and development trend of theories and technologies for coal and coalbed methane co-mining in China. At last, the development and utilization of coal and coalbed methane were studied and judged. [Results] The necessity and feasibility of implementing the coordinated exploration and development of coal and coalbed methane were scientifically validated and the main bottlenecks of coordinated exploration and development of coal and coalbed methane in China were revealed. Then this paper has established coordinated exploration and development of coal and coalbed methane technique system. At last, the new development mode, key technologies and development proposals of coordinated exploration and development of coal and coalbed methane were put forward. [Conclusions] It is very necessary and urgent to implement the coordinated exploration and development of coal and coalbed methane. The features of coalbed methane reservoir (low permeability, low reservoir pressure, low gas saturation), complex geological conditions and mining technical determined that the exploration and development mode of coalbed methane in China is dominated by cooperative exploration and development of coal and coalbed methane, supplemented by surface pumping. Under the carbon peaking and carbon neutrality goals. It is necessary to deepen the research on the law of reservoir forming of coal and coalbed methane coupling mineralization and accumulation, and establish a technical system combing the key technologies of coal and coalbed methane cooperative exploration, development and utilization with CCUS technology.
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zhengwei, MAO Jingwen, LIAO Ziqing, LUO PING, HUA Ronghui, DU Gaoxiang, CHEN Wei, ZHENG Zhongchao, HUANG Hongxin, REN Zhinong, CHU Kelei, WU Shenghua, YU Kuankun, SONG Shiwei
DOI: 10.12029/gc20230203001
Abstract:
Weiling pegmatite is a single orebody with a length of 1.5 kilometers, a width of 1 kilometer and an average thickness of 128 meters. The reserved resources of the Weiling deposit are more than 80 Mt, and the prospective resources are 200~300 Mt, the scale and type of which are really rare. What is more valuable is that pegmatite contains 5% high-purity quartz, and quartz, K-feldspar and mica can be fully utilized, with huge potential value and economic benefits. The preliminary experimental results show that the SiO2 purity can reach 99.994%. It is expected to form the first high-purity quartz producing area in China. The zircon 206Pb/238U age of the Weiling pegmatite is 388.5±3.1Ma, indicating that it was formed in the Early-Middle Devonian and is a super-large pegmatite deposit in the Caledonian.
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Chen Peng, Zhang Bing, Ma Rong, SHI Jiansheng, Si Letian, WU Jun, ZHAO Lefan
DOI: 10.12029/gc20220415002
Abstract:
This paper is the result of hydrogeological survey engineering. [Objective] Based on the health status and resilience of the ecosystem, a risk assessment system of lake basin ecosystem degradation was constructed to provide a scientific basis for ecological environment protection and sustainable development at the basin scale. [Methods] Taking the Chahannur Lake basin on Bashang Plateau as an example, the interactive risk assessment matrix of ecosystem health and resilience was created, the ecological degradation risk assessment system was established, and the risk assessment of ecosystem degradation in the Chahannur Lake basin was carried out. [Results] 91.10% of the region"s ecological health was in a good state, and 6.66% was excellent. In the basin, 22.76% of the regional ecological resilience level is 1-2, and 75.00% is 3-4. The results of the interactive assessment showed that 27.51% of the basin was in a state of low risk of ecological degradation, and 70.25% of the basin was in a state of medium risk. [Conclusions] The ecosystem of the Chahannur Lake basin is generally good, but the risk of ecological degradation is moderate in local areas due to poor resilience. The assessment method proposed in this study can accurately classify the risk level of ecological degradation at the watershed scale and provide a basis for the scientific decision-making of precise ecological protection and degradation control measures.
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XUE Qiang, ZHANG Maosheng, DONG Ying, MENG Xiaojie, GUO Xiaopeng, FENG Wei, HONG Bo, WANG Tao, LIU Wenhui, TIAN Zhongying, ZHANG Ge, LU Na
DOI: 10.12029/gc20220801001
Abstract:
This paper is the result of geo-hazards survey engineering. [Objective] The Loess Plateau is one of the regions with the most serious geo-hazards in China. The key to effectively and accurately prevent and control the loess geo-hazards is to precisely identify the hidden geo-hazards dangers and thoroughly understand the number of geo-hazards risks. [Method] This paper takes Mizhi County in the Loess Plateau region of northern Shaanxi as an example to perform the identification, investigation and evaluation of the hidden loess geo-hazards dangers step by step and establish the system of refined risk identification technology method for the loess geo-hazards at the county level. The DEM data with resolution of 2m × 2m is used to identify the slopes prone to induce collapses and landslides. The remote sensing data with resolution of 0.2m is applied to identify the dangerous slopes. The natural village is taken as the unit to investigate the dangerous slopes and evaluate their risks. [Results] The results show that: (1) a total of 44,716 landslide-prone slopes with inclination degree greater than 40° and height larger than 20m and 4,198 dangerous slopes with threatening objects were identified; (2) Through risk identification, field investigation and evaluation, the total number of geo-hazard risks in Mizhi County was thoroughly understand. There are 4406 geo-hazards risks, including 11 extremely high risks, 304 high risks, 1451 medium risks and 2640 low risks. (3) A number of 3880 risks accounting for 88.06% of the total risks were identified by the DEM and remote sensing with the identification accuracy of 92.42%. (4) From July to August 2022, 36 geo-hazards risks occurred, which are within the scope of this risk identification including 2 extremely high risks, 28 high risks, 5 medium risks and 1 low risk. The proportion of disasters located at extremely high risks is 18.18%, and the proportion of disasters occurred at high risks is 9.21%. The results of risk identification have been effectively verified. [Conclusions] The research results significantly reduced the losses caused by geo-hazards in Mizhi County, and provided scientific references for effectively and accurately preventing and controlling the loess geo-hazards.
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Liu Zhi-jian, Dong Yuan-hua, Zhang Xiu
DOI: 10.12029/gc20220705002
Abstract:
[Objective] Most of the food crops are low in zinc and it is difficult for humans to obtain sufficient zinc through the normal diet. Land quality geochemical survey, as Nature-based solutions, is the best scheme to find the suitable region for cultivating zinc-rich crops.[Methods] This study takes agricultural land in Wei Ning Plain of Ningxia as the research region, geochemical data of surface soils, wheat seeds and rhizosphere soils of agricultural lands were obtained through land quality geochemical survey, the geochemical characteristics of zinc in surface soil and wheat seed were studied, and the influencing factors of zinc enrichment in wheat seed were explored. The interval value of zinc content in zinc-rich wheat was calculated based on the nutritional structure of healthy diet in China and the reference intake of dietary nutrients in residents.[Results] In the research region, the range of zinc content in surface soils was 25.1 mg?kg-1 to 102.0 mg?kg-1, and the background value of surface soil was 61.4 mg?kg-1. The range of zinc content in wheat seeds was 13.34 mg?kg-1 to 37.78 mg?kg-1, the average content was 24.72 mg?kg-1, and the average bio-enrichment coefficient was 0.41. The range of zinc content in Zn-enriched wheat was 26.5 to 50.0 mg?kg-1, and the proportion of zinc enriched wheat seeds in the research region was 36.7%. Based on the neural network model, we predicted that the region of agricultural lands, which were suitable for cultivating zinc enriched wheat in Wei Ning Plain, was 242.86km2.[Conclusions] The spatial distribution of zinc in the surface soil of the research region was relatively uniform and was mainly controlled by soil parent materials. The zinc enrichment ability of wheat seeds was medium. The zinc enrichment ability of wheat seeds is significantly correlated with Zn, Fe2O3, K2O, SiO2/Al2O3 in rhizosphere soils. Neural network model can construct a reliable prediction model, which can be used as a method to explore suitable cultivating regions for beneficial micronutrient enrichment crops through geochemical survey data.
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CHENG Xianda, SUN Jianwei, JIA Xu, LIU Xiangdong, Zhao Yuanyi
DOI: 10.12029/gc20221116001
Abstract:
This paper is the result of geological environment survey engineering. [Objective] Luanchuan County is a typical molybdenum mining area in China. It is of great significance to find out the heavy metals pollution of farmland soil around the molybdenum mining area for regional environmental pollution prevention, mine ecological restoration and sustainable development of mining industry. [Methods] This study systematically investigated and analyzed 54 topsoil samples from the farmland in Chitudian Town around the typical molybdenum mining area, obtained the contents and spatial distribution characteristics of Cd, Cu, Zn, Pb, Hg, As, Cr, Ni, and evaluated the heavy metal pollution, ecological risk and health risk by the geo-accumulation index method, potential ecological risk index method and health risk index method. [Results] Compared with the risk screening values for soil contamination of agricultural land, Cd, Cu, Zn and Pb are the main elements exceeding the standard, As exceeds the standard with a few of samples, and Hg, Cr, Ni are not exceeded; The spatial distribution characteristics show that: Area A where around the molybdenum mining area is the main distribution area with high content of Cd, Cu, Zn and Pb, which decreases gradually with the increase of distance, and the order of over-standard value is area A>area B>area C; According to the values of geo-accumulation index, Hg, As, Cr and Ni are generally pollution-free, and the pollution of Cd is moderate to heavy degree, while Cu, Zn , Pb are light to heavy degree, showing the order of pollution degree are Cd > Pb > Zn > Cu and area A>area B>area C; In terms of potential ecological risk, study area shows slight ecological risk, which area A is higher than that of other areas B and C, and Cd is the most prominent element; The non-carcinogenic health risk index is less than 1, with the order of Cr > As > Pb > Ni > Cd > Cu > Zn > Hg, and the carcinogenic health risk index is less than 1×10-4, with the order of Ni > Cr > As > Cd, which is an acceptable risk level. The carcinogenic and non-carcinogenic health risk indexes of children are higher than those of adults. [Conclusions] There is a certain degree of heavy metals pollution of Cd, Cu, Zn and Pb in the farmland soil around the molybdenum mining area, reaching the degree of medium pollution to heavy pollution, but the overall ecological risk is low, and the risks of non-carcinogenic and carcinogenic health are within a reasonable range. The risk of people suffering from cancer and non-carcinogenic diseases due to the influence of heavy metals in the soil is low. Children are more sensitive and vulnerable to heavy metals, so it is necessary to strengthen protection.
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CHEN Binghan, LI Peng, LIU Jiannan
DOI: 10.12029/gc20220321002
Abstract:
[Objective] In the national dynamic evaluation project of potential mineral resources, the features, type and spatiotemporal distribution of caesium resource in China are studied, the metallogenic regularities of caesium deposits in China is summarized. [Methods] This paper introduces the resource characteristics of cesium deposits in China; Cesium deposit types are divided, and the mineralization age and spatial distribution of cesium ore are counted. [Results] Caesium deposits in China are divided into seven types, namely the granite type, granite pegmatite type, magmatic hydrothermal type, salt lake type, brine type, geyserite type, granite weathering crust type, the spatiotemporal distribution feature of each type of caesium deposits is preliminarily summarized. Based on the statistics, the metallogenic period of caesium deposits in China is divided into Paleozoic, Mesozoic and Cenozoic. 10 caesium metallogenic belts are divided. 31 caesium-related metallogenic series are determined and the metallogenic pedigree of caesium deposits in China is established. [Conclusions] China''s Cesium deposits are mainly Mesozoic and Cenozoic granite pegmatite type, granite type and salt lake type cesium deposits in north Altay and North China continental block, salt lake type in Qinghai Tibet Plateau, granite pegmatite, granite Cesium deposit and magmatic hydrothermal Cesium deposit in the middle and lower reaches of the Yangtze River. The exploration work in Xinjiang, the middle and lower reaches of the Yangtze River, the Qinghai-Tibet Plateau and the Qianjiang basin should be strengthened.
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zhaoguangshuai, suchuntian, huangqibo, zhuyinian
DOI: 10.12029/gc20211224002
Abstract:
【Objective】A large strontium-rich mineral water field was discovered in Xintian County, Hunan Province. However, the study on the source of strontium and the development and utilization potential of strontium-rich spring is relatively weak. Meanwhile, studying the hydrochemical characteristics and the source of strontium in strontium-rich karst water can provide some theoretical support to the search for strontium-rich groundwater in karst area. 【Methods】 Hydrogeological investigation, PHREEQC software, water stoichiometry, end element method and hydrogeological parameter were used to explore the characteristics of strontium-rich karst water minerals saturation index, the sources of Sr2+ and SO42-, and the development and utilization potential of strontium-rich groundwater. 【Results】Calcite is mainly saturated both in the spring and shaft, while dolomite changes from unsaturated in the spring to saturate in the shaft. Strontium is saturated in the shaft, and gypsum is unsaturated both in the spring and the shaft. In the spring, mineral saturation index increases with the increase of the total dissolved solids, and they have a good positive correlation, but the correlation is poor in the shaft. The SO42- in the spring and shaft had a good positive correlation. According to the stoichiometric relation of Ca2+, Mg2+, Sr2+, HCO3- and SO42-, SO42- in the shaft may come from gypsum dissolution. The Sr2+ in the spring is mainly derived from strontium replacing calcium with isomorphism in limestone, while Sr2+ in the shaft probably comes from strontium mine in the aquifer. 85.2% of the water points in the study area meet the standards for drinking water quality, and most of the water points exceeding the standard are single index exceeding the standard. Through calculation, the natural recharge resources, exploitable resources and groundwater resource potential of strontium-rich groundwater in dry years are 3.83×107m3/a、1.05×107m3/a、7.28×106m3/a respectively. 【Conclusions】Strontium in the strontium-rich groundwater in Xintian County is mainly derived from the dissolution of strontium-containing minerals (strontianite and strontium elements in isomorphic displacement). The amount and resource potential of strontium-rich groundwater are considerable, thus it has great potential and value to development and utilization.
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Zhao Chunhong, Liang Yongping, Wang Zhiheng, Tang Chunlei, Shen Haoyong
DOI: 10.12029/gc20220327001
Abstract:
【【Objective】With the characteristics of wide distribution, concealment, heavy pollution, slow natural purification and long duration, the "goaf water" of coal mine has become an important restrictive factor that seriously threatens the construction of ecological civilization in China in the post coal mining era. 【Methods】Taking the goaf water of coal mine in Shandi River Basin of Yangquan City, Shanxi Province as the research object, this paper systematically analyzes the dynamic characteristics and evolution mechanism of water quantity and quality of goaf water in Shandi River Basin by using a long series of systematic monitoring of water quality and quantity, and statistical methods. 【Results】The results indicate that the average pH of the total outlet of "goaf water" in Shandi River is 3.58, the average TDS is 4744 mg/L, and the average SO42- is 3327 mg/L. After the rise of groundwater level in rainy season, the increase of contact area or volume and the lag of rainfall are the main reasons for the nonlinear correlation between the flow of goaf water and the conductivity and SO42- concentration of hydrochemical characteristic indexes. The strong oxidation reaction of pyrite in coal measure strata mainly occurs in the seasonal variation zone of groundwater level, aeration zone and surface. The certain depth of the gob ponding area of the coal mine is the reduction environment, which has the conditions for microbial treatment. After the "goaf water" flows out, the leakage recharge in the downstream carbonate section is 7247.08 m3/d, and the water quality is poor, which is an important pollution source of karst groundwater in Niangziguan Spring area. 【Conclusions】The regulation and storage period of "goaf water" flow to rainfall in Shandi river basin is half a year. The hydrochemical characteristic index is nonlinear related to the flow. The strong oxidation reaction of "goaf water" pyrite mainly occurs in the seasonal fluctuation zone of groundwater level, aeration zone and surface. After the "goaf water" flows out, the leakage recharge in the downstream carbonate section is 7247.08 m3/d, SO42-, Fe and Mn exceed the standard seriously, which is an important pollution source of karst groundwater in Niangziguan Spring area. It is urgent to carry out the treatment of "goaf water" in coal mines and the ecological restoration of abandoned coal mines.
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ZhangHaizu, XuTong, XieYani, ZhangHuifang, Fanshan, Chenchangchao, ZhuChuanqing
DOI: 10.12029/gc20210830002
Abstract:
The distribution relationship between oil and water in Ahe Formation of Jurassic in the eastern Kuqa Depression, Tarim Basin is complicated, and the characteristics of formation water and its relationship with oil and gas reservoirs are lack of systematic study. In order to clarify the chemical characteristics of formation water and its relationship with reservoirs, based on the selection of formation water samples, the formation water test data of Ahe Formation in eastern Kuqa Depression are analyzed to study the distribution characteristics of water type, TDS and ionic ratio coefficients of formation water and its significance to reservoirs. The results show that the formation water of J1a is mainly NaHCO3 type,followed by CaCl2 type and MgCl2 type, and has relatively low salinity. The TDS and ionic ratio coefficients of formation water are controlled by the structure characteristics: In the open area of the structure and the pinch-out area of the formation, the formation water is mainly NaHCO3 type with low salinity, the sodium chloride coefficient and desulfurization coefficient are high and the deterioration coefficient is negative. Nevertheless, the formation water in the closed formation has the opposite chemistry feature. There is a good coupling relationship between the chemical characteristics of formation water and the plane distribution characteristics of oil and water, with Dibei oilfield as an example, although YN4 and YS4 wells had experienced oil and gas filling, but the formed oil and gas escaped along the fault, and the chemical characteristics of the formation water and the kaolinite content reveal that the formation was affected by the meteoric water that entered along the fault. On the contrary, the chemical characteristics of formation water and kaolinite content in well YN2 indicate that the formation is well sealed and less affected by meteoric water, which corresponds to the distribution of oil layers. The relationship between the chemical characteristics of formation water and the distribution of oil and gas reservoirs provides a basis for subsequent exploration, development and evaluation of tight oil and gas reservoirs.
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Li ZhiZhong, Luo TengYue, ZhangYi, Xia Peng, Mu Huayi, Sun Pingping, Wang Jianhua, Wang Xin
DOI: 10.12029/gc20221009002
Abstract:
[Objective] Ordos Basin is an important energy base in China, with rich oil, natural gas and coal resources, bauxite, uranium and other mineral resources. Bauxite is abundant around the basin, but there is little research on deep bauxite in the basin. Oil and gas drilling shows that the basin is rich in bauxite resources, with a buried depth of one hundred to four kilometers. If the exploration and mining of deep bauxite can be realized, the situation of insufficient bauxite resources in China will be greatly alleviated. [Methods] The geological characteristics and petrophysical characteristics of bauxite in Tongchuan area, Ordos basin are studied in this paper. [Results] First, the deep bauxite in the basin has obvious electrical characteristics, which is characterized by "four high and two low". With reference to oil and gas logging interpretation methods, bauxite identification standards and bauxite logging interpretation models can be established to obtain diaspore content and complete the evaluation of bauxite; Second, the distribution of bauxite in the basin is controlled by the palaeogeomorphology of the Paleozoic Majiagou Formation, and the ore bed is stably distributed, with considerable resources and great exploration potential; Third, bauxite belongs to sedimentary rock, which has certain porosity and permeability, and presents sandwich structure. The bauxite ore bed with high permeability is often surrounded by clay rock with low permeability, meeting the geological conditions of in-situ solution mining; Fourthly, according to stress sensitivity analysis, bauxite is compressible, and new pores or cracks will appear under certain stress, which can further improve the permeability of the ore bed and increase the possibility of in-situ leaching mining of bauxite. [Conclusions] Logging technology can be used to evaluate the deep bauxite resources in Ordos Basin. In combination with the petrophysical characteristics of bauxite, in-situ leaching mining can be considered for bauxite.
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Wang Zhenli, Zhang Lian, Luo Jianlin, Li Fuping, Lei Tianci, Huang chang sheng, yu dong sheng, Deng Tongde
DOI: 10.12029/gc20220826001
Abstract:
This paper is the result of eco-geological survey engineering. [Objective]The purpose of this paper is to study the relationship between the quality of taro and the eco-geological environment, explore the eco-geological mechanism that the eco-geological environment to create the special flavor of taro, provide a scientific basis for the selection or improvement of the eco-geological environment for taro planting, and provide a reference for the research of related disciplines. [Methods] Study was carried outfrom the aspects of geological construction control, soil parent material traceability, soil physics, soil geochemistry, biogeochemistry, etc.Systematic sampling of rocks, soil, waterand plants was donein the core area and the control area of the taro. Themineral elements, organic nutrients and main indexes of physical properties of farmland soilwere detected. The test data were analyzed and processed by a variety of methods and studied comprehensively. [Results] The results show that:① The main indexes reflecting the unique flavor of taro were higher than those in the control area, such as protein, energy, carbohydrate, vitamin B, starch, amino acid, etc. ② The essential elements K, P, Zn and S played a major role in the formation and improvement of taro flavor substances, followed by Fe, Mg, Cl, Ni, Mn, Ca, Cu and SOM. ③ The average soil particle size is small, the soil bulk density and soil compactness is low, the soil burning reduction and pH value is moderate, and the soil moisture and soil Eh value is higher, the soil is well cultivable. [Conclusions] The unique flavor of Jibu taro is the product of the superposition effect of excellent soil physical, soil geochemical and biogeochemical characteristics caused by a unique eco-geological environment.
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Jin Yang, Jiang Yuehua, Zhou Quanping, Wang Xiaolong, Zhang Hong, Mei Shijia, CHEN Zi, Yang Hai, Lv Jinsong, HOU Lili, Qi Qiuju, JIA Zhengyang, Yang Hui
DOI: 10.12029/gc20220331001
Abstract:
Abstract：Abstract：【Objective】 There are numerous water-intakes along the mainstream of the Yangtze River downstream, in order to ensure water safety and eco-environmental health, relevant situation of heavy metals in the nearshore sediment need to be studied urgently. 【Methods】 A total of 85 sediment samples were collected on both left and right banks from the upstream to the downstream with the investigation. Descriptive statistics analysis was used to show the characteristics of heavy metals. Correlational analysis and principal component analysis (PCA) were applied to determine the sources of heavy metals. Geoaccumulation index and pollution load index were used to analyze the pollution levels, and the potential ecological risk of heavy metals were evaluated by the methods of potential ecological risk assessment index.【Results】 The order of average content from high to low is Zn＞Cr＞Cu＞Ni＞Pb＞As＞Cd. From the upstream to the downstream, Cu、Zn、Cr、Ni had a small fluctuating but increasing trend, while As and Pb had a small fluctuating but decreasing trend, Cd showed decreasing trend with an obvious fluctuation. The most polluted one is Cd among seven heavy metals, which were mainly from human activities, such as agriculture. Cd accounted for 1.18%, 1.18%, 18.82% and 34.12% from polluted Class 1 to 4, respectively. Cr and Ni were non-pollution class, which mainly from industries and geochemical natural source. 34.18% of all sampling sites were in moderate pollution (1≤PLI point＜2). RI was ranged from 19.48 to 388.62, and the proportions of slight potential ecological risk, medium potential ecological risk, strong potential ecological risk and extremely strong potential ecological risk were 38.82 %, 42.35 %, 17.65 % and 1.18 %, respectively. 【Conclusions】Concentrations of all heavy metals in mainstream sediment of the Yangtze River downstream were at a lower level. The catchment were overall at non-pollution sate (PLI area＜1 )with slight to moderate ecological risk. The average concentrations, pollution levels and potential ecological risks of heavy metals on the right bank were all higher than those on the left bank.
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JIN Wenzheng, BAI Wankui, YE Zhixu
DOI: 10.12029/gc20220306001
Abstract:
Abstract: This paper is the result of geological survey engineering. [Objective] In order to discuss the relationship between the vertical tectonic uplift and the lateral tectonic expansion happened in Meso-Cenozoic in the Longmenshan thrust belt, this paper carries out low-temperature thermal chronology testing and analysis. [Methods] Through the determination and analysis of apatite and zircon fission track age, the characteristics of tectonic evolution are studied. [Results] The study shows that the lengths of apatite fission tracks are within the range of 11.4±2.6~12.2±2.2μm, which can effectively reflect the local tectonic uplift history; the results of thermal history simulation show that the apatite samples have experienced three critical stages, including the rapid tectonic uplift, the stable tectonic stage and the rapid tectonic uplift. Besides, the uplifting events happened in the northern area were earlier than those in the southern area. The cooling rate of each rock sample is within the range of 1.211~6.053℃/Myr. The tectonic uplift rate gradually increases from southeast to northwest, and the time of uplifting gradually becomes late in the same direction. [Conclusions] The tectonic deformation of Longmenshan thrust belt has had the characteristics of piggyback propagation from northwest to southeast since Meso-Cenozoic (150Ma), and it has showed these characteristics again from late Cretaceous to Eocene (70~50Ma), even Oligocene (about 20Ma). The central and western regions of the Longmenshan thrust belt are characterized by multi-stage tectonic uplift and superposition.
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HANJIAN, CHENQISHEN, YANGXUESONG, LONGTAO, XINGJIAYUN, LIQIONG, ZHAOHANQING, SHIMINJIE, PANZHIJUN
DOI: 10.12029/gc20220918003
Abstract:
【【Objective】Cobalt is an important new energy mineral, the rapid increase in the installed capacity of power batteries has brought broad market prospects for cobalt, grasping the characteristics of cobalt resources and the supply and demand situation is of great significance for the geological exploration industry and the back-end industrial chain.【Methods】Mainly through the investigation method, quantitative analysis method and qualitative analysis method, analyze, compare, and summarize large amounts of data collected in surveys.【Results】this paper analyzes the characteristics of global cobalt resources and the supply and demand situation from the aspects of global resource distribution characteristics, supply and trade patterns, consumption history and trends, and at the same time makes research and judgments on the prospects of the cobalt market based on the status quo of the industry. 【Conclusions】First, cobalt resources that can be developed and utilized in the world are relatively concentrated, sedimentary sandstone copper-cobalt deposits are mainly in Congo (Golden), weathered laterite nickel-cobalt deposits are mainly in Australia, and magmatic rock-type copper-nickel-cobalt sulfides deposits are mainly in Canada; second, the cobalt exploration funds mainly flowed to the Congo (DRC), Australia, Canada and the United States, but the exploration investment has not yet been converted into production capacity, and global cobalt production has declined; third, the market share of global cobalt mining giants is gradually increasing, and they are evolving into a "duopoly" situation; fourth, the battery-based consumption structure and China-based consumers have supported the continuous and stable growth of global cobalt consumption;fifth, the global mainstream institutions are unanimously optimistic about the prospects of the cobalt market, this article predicts that the cobalt market will continue to prosper in the next 5-10 years, but it is necessary to be alert to risks such as technological innovation and replacement in the battery industry.
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YANG Peng, LI Jian-fen, WANG Fu, HU Yun-zhuang, SHI Baojia, WANG Wenyu, WANG Hong
DOI: 10.12029/gc20220613002
Abstract:
Abstract: [Objective] Oyster reef has important ecological value, and studying its present situation is of great significance for coastal ecological protection and restoration. [Methods] This article reviewed the investigation and research data of the natural oyster reefs at home and abroad. In addition, the present situation, historical changes, as well as the major ecological problems of the natural oyster reefs in China were also discussed. On the basis of the results, combined with indigenous and abroad oyster reef ecosystem restoration practices, suggestions on the protection and restoration of the natural oyster reefs in China were put forward. [Results] The results show that the global oyster population has declined by 85% over the past century, with more than 90% of reefs in the Asia-Pacific region have already disappeared. The natural oyster reefs in China are also severely degraded, and the known natural living oyster reefs are mainly distributed in Caofeidian, Hebei, Dashentang, Tianjin, Binzhou Port and Laizhou Bay, Shandong, Xiaomiaohong, Jiangsu, Shenhu Bay and Kinmen, Fujian, etc. The existing oyster reefs in severely degraded areas are less than one-tenth of what they were in the past, causing serious damage to the structure and function of the estuary and coastal ecosystems. Therefore, the protection and restoration work is needed urgently. [Conclusions] The practices of oyster reef restoration at home and abroad show that it is feasible and quite significant to carry out area restoration of oyster reef ecosystem. In order to make full use of the ecological service function of oyster reefs, provide support for the ecological restoration, and improve the carbon sequestration capacity of coastal zones, this paper proposes four suggestions on protection and restoration, including promoting relevant legislation on oyster reef protection, conducting systematical survey and research on the natural living oyster reefs, pilot to carry out oyster reef restoration demonstration projects, and constructing "China Coastal Oyster Reef Eco-Corridor".
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Wei Hao, Wei Xiaofeng, Wang Jingbin, Zhu Sujia, Yang Fan, Liang Zhao, Tian Xiaoxia, Li Wei, Jia Wenru, Yu Kaining
DOI: 10.12029/gc20211017001
Abstract:
Objective：To find out the distribution characteristics and geological genesis of soil selenium in Chengde area, so as to provide scientific basis for the exploration and effective utilization of local soil selenium. Method: The types of soil parent materials in this area were identified by geological survey. The contents of selenium and multiple elements in 553 soil samples and 66 rock/ore samples were obtained by X-ray fluorescence spectrometry, inductively coupled plasma emission spectrometry and Kjeldahl nitrogen. The data were analyzed by SPSS software and the geological genesis was analyzed combined with geological process. Results: the soil parent materials in Chengde area are roughly divided into nine categories. The minimum value of selenium content in surface soil is 0.016 mg/kg, the maximum value is 0.743 mg/kg, and the average value is 0.17 mg/kg. The average soil selenium content is only 1 / 2 of the national average selenium content, which is in a lack level. The average selenium contents in iron ore, gold ore and lead-zinc ore were 0.860, 1.233 and 3.365 mg/kg, respectively, which were significantly higher than those in tailings and surrounding rocks of various ores. Conclusions: The overall content of soil selenium in Chengde is very low, which is mainly determined by the parent material, and its distribution characteristics are controlled by geological formation. Selenium-rich soil areas are concentrated in the south of Longhua County ( Area A ), the south of Chengde City ( Area B ) ( Shuangluan District, Shuangqiao District) and the eastern Kuancheng County ( Area C ). Area C belongs to the "rock weathering type", which is related to the combination of primary carbonate rock and carbonaceous mudstone with high selenium content. Area B belongs to " mineralization associated type ", which is related to the associated relationship between selenium and metal sulfide and the substitution relationship between selenium and sulfur in the process of lead-zinc mineralization. Area A belongs to the " river sedimentary type ", which is related to the driving force of rivers and lakes and the adsorption of organic matter in the process of channel deposition. The selenium-rich region in southern Chengde has the natural advantage of developing forest and fruit economy. Weichang County is in a low selenium environment, which is one of the factors leading to the epidemic of Keshan disease and other local diseases.
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DOI: 10.12029/gc20200316001
Abstract:
【Objective】The pore system of shale plays an important role in shale reservoir evaluation. There are many experiments to characterize the pore system. Different experiments have advantages and limitations，and are restricted by different areas and strata samples. 【Methods】In this paper，CO2 adsorption，N2 adsorption，high-pressure mercury injection experiment and nuclear magnetic resonance experiment are used to study the shale samples of Shanxi Formation in Ordos Basin，In addition，the pore characterization results of Taiyuan Formation shale samples in Qinshui Basin are compared，and the applicability of different experiments to the marine terrestrial transitional shale is analyzed. 【Results】For different experiments of the marine terrestrial transitional shale reservoir，the characterization advantage interval is 0.01~40nm，0.3~1.1nm，2~50nm，respectively； The MIP advantage range is > 50nm. The experimental range is MIP，NMR，N2 adsorption，CO2 adsorption from large to small；the test accuracy and the highest resolution are NMR，CO2 adsorption，N2 adsorption，MIP from high to low. 【Conclusions】Compared with the fluid injection method，NMR has more advantages in characterization when there are closed pores and bound water in the pores，resulting in different selection of characterization advantage range.
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WANG Lixin, LIU Jun, Wang Lipeng, WANG Qingtong, YAN Kun, JIANG Wenqin
DOI: 10.12029/gc20210422001
Abstract:
This paper is the result of regional geological survey. [Objective] The study of paleo- environmental changes of Mid- to Late- Pleistocene in northwest Tarim Basin is relatively weak. As a sensitive area to climate and environmental change in Asia, the paleoenvironment study of the Southwest Tianshan is of great significance for predicting future climate. The succession law of palaeo-vegetation indicated by the characteristics of palynological assemblage has become an important problem to be solved urgently in paleoclimate research in this area. [Methods] Based on palynological identification and photoluminescence dating of typical river terrace samples from Sepayi-Keping area, Xinjiang, the characteristics of palynological assemblages in the Mid- to Late- Pleistocene and their implications for paleoclimate were discussed in this paper. [Results] Three palynological assemblages of Mid- to Late- Pleistocene were divided. Palynological assemblage zone Ⅰ: Quercus- Graminae- Chenopodiaceae; Ⅱ: Ephedra- Betula- Labiatae; Ⅲ: Pinus- Ephedra- Chenopodiaceae. [Conclusions] They indicate the arid climate of the Southwest Tianshan and the fluctuation trend (dry and cold - warm and wet - dry and cold) during Mid- to Late- Pleistocene. During 65-16 ka before present, there was an obvious humid climate stage with abundant precipitation. The terraces formed by river downcutting were controlled by both tectonic and climatic factors.
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WAN Feipeng, YANG Weimin, QIU Zhanlin, xianglinzhi, QU Jingkai, WU Jihuan, ZHANG Tiantian
DOI: 10.12029/gc20220323005
Abstract:
【Objective】Nagune gully is a small-scale with high frequency debris flow gully and located in Eryanggou watershed, Chabu Town, Min County, Dingxi City, Gansu Province, and structurally located in the branch fault zone of Lintan-Dangchang fault. The landslide developed in the basin makes the basin produce a special landslide-debris flow disaster chain. The disaster mechanism and evolution process of the disaster chain are worthy of in-depth study. 【Methods】Through field investigation and remote sensing interpretation, combined with laboratory experiments, clarified the development characteristics of disasters in Nagune gully, studied the formation mechanism of disaster chain of landslide-debris flow, and dissected the evolution process of disaster chain of landslide-debris flow under fault activity environment in the small watershed. 【Results】The results show that: The disaster chain of landslide-debris flow in Nagune gully is in the form of reciprocating development of debris flow-landslide-burst flood debris flow. The activity of fault makes the development of loose material source and unstable slope, which lays the geological foundation for the formation of disaster chain, the frequent short-term concentrated rainfall and continuous rain stimulate the occurrence of debris flow, the erosion effect of debris flow on the valley makes the slope unstable and forms landslide, the landslide blocks the valley and then the burst flood debris flow is formed after the barrier lake breaks the dam. The evolution process of landslide-debris flow disaster chain is determined as follows: debris flow formation and erosion gully stage, slope deformation and gradually approaches the critical instability stage, landslide slides down and blocks the channel to form a barrier lake stage, barrier lake burst then forms burst debris flow stage, the slope in the opposite is eroded and slides down stage, the reciprocating development stage of debris flow-landslide-burst flood debris flow stage. 【Conclusions】To sum up, the formation of the disaster chain in Nagune gully is the result of the current fault activity, short-term concentrated rainfall or continuous overcast rain; The continuous occurrence of debris flow and the continuous creep of landslide in annual rainy season lead to the continuous process of debris flow-landslide-burst flood debris flow.
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Tian miaozhuang, ZHAO Long, SUN Aihua, LIU Her, CUI Wenjun, LUN Yong, GUO Gaoxuan
DOI: 10.12029/gc20220105002
Abstract:
Abstract: [Objective] Overexploitation of groundwater in Beijing has caused serious land subsidence since the 1980s. After the south water entered Beijing in 2014, closure of self-contained water-source well and water-source replacement, groundwater mining restriction, and ecological water supplement carried out on a large scale in Beijing led to a significant rise in groundwater table, ground subsidence slowed down, even rebounded in some areas. Response of ground subsidence to groundwater table rise is a complicated process. The relevant research is of great significance to the prevention and control of land subsidence in Beijing, further providing reference for the prevention and control of land subsidence in China .[Methods] The plain area of Chaobai River Basin was selected in this study, the spatial monitoring of regional land subsidence and groundwater was carried out by using synthetic aperture radar interferometry, land subsidence layered mark monitoring technology and groundwater layered monitoring technology were used to verify the response characteristics of land subsidence to the rising groundwater table. [Results] (1) With the recharge of Chaobai River groundwater, the maximum water table of the first and second confined aquifers returned 25.49m and 25.67 m, respectively. (2) The maximum rebound rate and rebound range of the region from 2015 to 2020 were basically consistent with the water table contour in the groundwater rising area. (3) In the middle and upper reaches of alluvial fan of Chaobai River, the soil compression of different lithologic soil layers continued slowing down or rebounding under the groundwater table restoration mode. But the groundwater table continued declining in the downstream area where groundwater was not recharged, and the soil deformation continued compressing. [Conclusions] The ecological water supplement of Chaobai River led to the increase in groundwater table, which effectively controlled the rapid trend of land subsidence development.
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zhangzhaozhi, panzhaoshuai, chedong
DOI: 10.12029/gc20220909002
Abstract:
【Objective】Chromium, as one of the critical minerals in China, supports the development of China''s emerging industries. China is short of chromium ore resources, poor resource endowment and low production. For a long time, the chrome ore has been highly dependent on foreign countries. It is important for the development of metallurgical industry and economic stability to study the future supply and demand of chrome ore. 【Methods】This paper summarizes the geology, spatial distribution, resource reserves and other characteristics of chromium deposits in China, and analyzes the historical data of the development and utilization of chromium resources in China. On this basis, the chromium supply in China is analyzed and predicted. And the stainless steel production and chromium demand in 2021-2035 in China are predicted under three scenarios, namely high, medium and low, by using chromium sector consumption method, S-curve of per capita stainless steel production, ARIMA model method (stainless steel) and other prediction methods.【Results】The research results show that：(1)the production of chromium in China will be 150,000-200,000 tons, and the secondary chromium will be 1.82-2.84 million tons from 2021 to 2035;(2)On the medium scenario, per capita stainless steel production will keep an upward trend from 2021 to 2032, and will reach its peak in 2032. At that time, the per capita stainless steel production will be 45.46 kg, the stainless steel production will be 64.99 million tons, and the chromium demand will be 11.04 million production; After that, it will gradually decline. By 2035, the per capita stainless steel production will drop to 30 kg, the stainless steel production will be 42.8 million tons, and the chromium demand will be 7.27 million tons; (3)The supply and demand situation is severe in China from 2021 to 2035, and the external dependence rate of chromium will exceed 99%. If secondary chromium production is used, the external dependence rate of chromium will drop to more than 69%【Conclusions】The supply and demand situation of chromium in China will still be severe, and the gap still needs to be supplemented by a large number of imported ores from 2021-2035. On this basis, it is proposed to strengthen the geological exploration of chromium ore, strive to achieve a breakthrough in chromium ore prospecting, attach importance to the secondary chromium recovery, develop the secondary chromium recovery industry, strengthen the reserves of chromium ore products, ensure the safety of chromium ore product supply, optimize the structure of chromium ore products, and make use of overseas chromium ore resources and products. The conclusions and suggestions formed in this paper are of practical significance to the compilation of mineral resources planning and the formulation of chromium mineral resources management policies in China.
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CUIJunyan, Li Shengtao, Yao Yahui, Liu Donglin, Liu Weipeng, Wang Junzhao
DOI: 10.12029/gc20221019002
Abstract:
[Objective] Geothermal energy, as a kind of clean and efficient renewable energy, is gradually attracting the attention of all countries under the dual drive of energy shortage and climate change. The development of geothermal resources has become an important way to accelerate the adjustment of energy structure and achieve the goal of "double carbon". In recent years, Türkiye"s geothermal energy industry has developed at a high speed. By 2021, the total installed capacity of geothermal power generation will be about 30 times that of China, and the direct utilization of geothermal energy will increase from 1177MWth in 2005 to4000MWth in 2022, making these remarkable achievements. Türkiye and China are both located in the Mediterranean Himalayan geotropics, where geothermal resources are abundant. The development of Türkiye"s geothermal energy industry is of great significance to China.[Method] This paper uses the method of literature review to analyze the conditions of geothermal resources in Türkiye, study the development status of geothermal energy industry, and summarize the reasons for its rapid development. Combined with the conditions and development status of China"s geothermal resources, and drawing on Türkiye"s experience, this paper analyzes the main problems affecting China"s geothermal development, and puts forward countermeasures and suggestions.[Results] The research shows that since the 21st century, Türkiye"s government has vigorously supported the development of geothermal energy industry. The reasons and main experiences of its rapid development include: (1) the government undertakes the preliminary exploration work, effectively reducing the development risk of enterprises; (2) Policy guidance and legislative subsidies can effectively improve the enthusiasm of development enterprises and reduce investment costs; (3) Financing support to provide financial guarantee for geothermal energy development; (4) International cooperation and technology guidance will effectively promote the efficient development and utilization of geothermal energy. [Conclusion](1) Improve geothermal energy management mechanism and define the process of geothermal development and utilization; (2) Effectively improve the enthusiasm of enterprises development and reduce investment costs through policy guidance and subsidies; (3) Realize efficient development of geothermal industry through reasonable spatial planning; (4) Strengthen international exchanges and help technological progress; (5) Improve social awareness of geothermal energy.
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SONG Teng, LIN Tuo, LI Fei, LI Haohan, WU Hai, DUAN Ke
DOI: 10.12029/gc20210602004
Abstract:
Objective: Marine black manganese-bearing carbonaceous shale of Datangpo Formation was generally developed in the mid-Neoproterozoic Nanhua period in the Middle-Upper Yangtze Region，South China, which has been widely concerned as a manganese deposit for a long time, but with little attention to its petroleum geological characteristics. This paper expounds the lithofacies paleogeography of the Datangpo Formation and its indication of oil and gas accumulation, so as to guide the oil and gas investigation in the Suthern China. Methods: Through field investigation and data collection on the Datangpo Formation, the oil and gas geological conditions, the source rock characteristics and hydrocarbon accumulation assemblage, especially lithofacies and paleogeography, were systematically analyzed by methods of single well analysis, continuous well comparison, lithofacies paleogeographic map compilation, etc., combined with source rock characteristic analysis, reservoir analysis and other experimental testing methods. Results: The Datangpo Formation was formed during the interglacial period, and the depositional process was controlled by the extensional rifting process. Its sedimentary facies can be divided into two types, seven subtypes and several microfacies. The entire depositional period constitutes a complete transgressive-Highstand-Regressive sedimentary cycle; the most potential facies belts for oil and gas resources in the Datangpo Formation are limited shelf subfacies and lagoon subfacies, mainly distributed in the first member, with good organic geochemical index characteristics, and are high-quality source rocks. Conclusions: The first member of the Datangpo Formation has good hydrocarbon generation and shale gas development potential. Songtao, Huayuan, Xiushan, Xiangtan, Hefeng and other areas at the junction of Hunan, Chongqing and Guizhou Province have favorable conditions for shale gas development and are potential shale gas development areas. With the Datangpo Formation as the source rock, a variety of potential reservoir-forming assemblages can be formed. The Xiushan, Songtao and Huayuan areas at the junction of Chongqing, Guizhou and Hunan Province have good source-reservoir configuration conditions and are potential conventional oil and gas development areas.
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ran tao, xu ru ge, zhou hong fu, zhang jing hua, chen hao, wang yu ke, sun jie, Cui Yanzong
DOI: 10.12029/gc20220329004
Abstract:
Abstract: This paper is the result of geological hazards survey engineering. [Objective]The Yalong River basin is an important base of forestry and animal husbandry, hydropower and energy, and minority communities in the west of China. It is of great significance to study the causes and distribution of landslides in the Yalong River basin for formulating scientific disaster prevention and mitigation strategies and ensuring the stable development of economy and society. [Methods]The Zituoxi–Malangcuo river section in deeply-incised valley area of Yalong River basin was taken as the study area in this paper. The basic landslide data were obtained through high-resolution satellite remote sensing interpretation, InSAR analysis and field investigation; typical types of landslides and their formation mechanism were summarized and analyzed by engineering geology analysis method; the distribution regularity and dominant development range of landslides were revealed by means of GIS spatial analysis and statistical method. [Results]The results showed that: (1) A total of 606 landslides were identified in the study area, among which the landslide with an area of 104 ~ 105 square meters was the most, accounting for about 60 percent of the total, and the number of landslides with areas of 103 ~ 104 and 105 ~ 106 square meters were essentially equal, accounting for about 20 percent of the total respectively; (2) Landslides were divided into five main types, i.e. rainfall-induced type, structure-controlled type, excavation-induced type, river erosion type and water impoundment-induced type, according to the main controlling factors of landslides. The key mechanism responsible for the occurrence of landslides mainly including the weakening effect of rock and soil strength by rainfall and impounded water, the deterioration effect of rock structures and its mechanical properties by fault structures, and the release effect of the anti-sliding and supporting action at the front of slope caused by excavation and river erosion; (3) The dominant terrain ranges for landslide development were of elevation 2500 ~ 3500 m, slope angle 15° ~ 35°, and slope aspect NE ~ E and S ~ W; (4) The soft metamorphic rock group composed of thin-bedded slate and silty slate was the dominant lithological group for development of landslides, while landslides in the magmatic rock group consisted of hard intrusive rocks such as granite and quartz diorite was the least; (5) the Kangdu fault, Qianbeinima fault, Zhusang fault, Tanggang fault, Huozezhari fault and Nieda fault were found having less impact on the development of landslides, however, landslides developed densely at both sides of the Mazishi fault, Chengzhang fault, Rangong fault and Jida-Milong-Muhui fault and at zones where these faults intersected in the downstream of the study area; (6) A negative correlation between the distribution of landslides and the distance to the river systems can be obviously seen, and a distance to the river systems of 0 ~ 0.5 km was found to be the dominant distance range of landslide development. The landslides were concentrated along the river valleys like belts macroscopically. [Conclusions]The research results could provide a significant scientific basis for understanding the causes and regularities of landslides in the deep-incised valley of Yalong River as well as for preventing and controlling the risk of chain of geohazard in the river basin.
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PAN Liangyun, MENG lingjian, SUN Fuli, YANG Wenjun, ZHANG Wei, REN Lu, XUE Hui, ZHOU Bo, YANG Hui
DOI: 10.12029/gc20220304001
Abstract:
【Objective】The Datong Basin is a Cenozoic rifted basin with superior geothermal geological conditions. However, due to the lack of geophysical and drilling datas in the basin, the research on the basin structure, sedimentary strata distribution, geothermal geological characteristics and resource evaluation is relatively weak. To a certain extent, it restricts the potential understanding and development and utilization of geothermal resources in the Datong Basin.【Methods】This paper comprehensively applies the new two-dimensional seismic and drilling logging data, such as oil and gas exploration and geothermal exploration, to carry out research on the geological structure, faults, sedimentary strata, and geothermal geological characteristics of the northern Datong Basin, evaluate the potential of geothermal resources, and estimate the geothermal energy. The amount of resources indicates the favorable area of geothermal resources.【Results】The Datong Basin is divided into five secondary tectonic units: Huairen sag, Sangganhe sag, Yingxian sag, Huanghualiang low uplift, and Sangganhexi uplift; Geothermal geological conditions and geothermal resource potential, two sets of thermal reservoirs, Neogene sandstone and Archean bedrock, are mainly developed, and a thick Quaternary thermal caprock is developed. The high-value area has the potential of Neogene sandstone and Archean bedrock layered geothermal resources, with a total static resource of about 68.8x1015 kJ, equivalent to about 2.347 billion tons of standard coal.【Conclusions】The comprehensive evaluation shows that the western part of the Huairen sag and the northern part of the Sangganhe sag in the Datong Basin are the first-class areas of hydrothermal geothermal resources, which are favorable target areas for geothermal exploration and development. The water inflow rate of a single well can reach 60m3/h. The northeastern part of the Huairen sag and the southwestern part of the Sangganhe sag are the second-class areas of geothermal resources. The geothermal resources of the Huanghualiang low uplift and the Sangganhe west uplift are relatively poor.
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MA Jian-fei, LI Xiangquan, ZHANG Chunchao, FU Changchang, XIE Xiaoguo, WANG Xiaogang, LI Xinze, ZHANG Dengfei, BAI Zhanxue, WANG Zhenxing
DOI: 10.12029/gc20220416004
Abstract:
Abstract:【Objective】 There are many tectonic karst areas in the east of Qinghai-Xizang Plateau, with complex karst hydrogeological structure, diverse recharge sources and abundant groundwater. Conducting the analysis and research of recharge sources and summarize the plateau tectonic karst cycle law is of great significance for guiding the development and utilization of karst water resources, ecological protection and disaster prevention and reduction.【Methods】 Based on field investigation, flow measurement, hydrochemistry and stable isotope analysis, this paper analyzes the groundwater recharge sources in typical karst areas in the east of Qinghai-Xizang Plateau, the influencing factors of recharge sources and recharge progress were discussed, and suggestions of development and utilization were put forward. 【Results】 The results show that the main recharge source of the main karst springs in the eastern Qinghai-Xizang Plateau is atmospheric precipitation. Four recharge modes are established, including direct recharge through fissure in high-level, continuous recharge by high-level lake, continuous seepage recharge in catchment depression, river seepage recharge. 【Conclusion】 The reason for the difference of recharge modes is that the eastern Qinghai Xizang Plateau has experienced internal and external dynamic coupling for a long time, in which the internal dynamic control factors are karst formation and evolution history, geological structure and lithologic combination; The external dynamic control factors mainly include meteorology, landform and glacier movement. According to the characteristics of water quality and quantity of karst spring, three development and utilization modes are put forward: the first is karst spring with water quality of class I ~ III, which can directly expand the degree of development and utilization, the second is brackish water, which can be properly developed and utilized after mixing with other water, and the third is salt water, which can be properly transformed and used for tourism development.
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LU Li, FAN Lianjie, peilixin, ZOU Shengzhang, LIN Yongsheng, DENG Rixin, Wang Zhe
DOI: 10.12029/gc20220603001
Abstract:
This paper is the result of the water resources and environmental geological survey engineering. [Objective] As the largest special economic zone in China, Hainan is not only the pilot free trade zone, but also the strategic fulcrum of the Maritime Silk Road, playing a pivotal role in the national strategy of "One Belt and One Road". To master the exploitation and utilization of groundwater resources and ecological environment is helpful to promote the sustainable development of Hainan. [Methods] This paper analyzed the situation of groundwater resources and drinking water safety in Hainan Island from the aspects of dynamic characteristics of groundwater, quantity and quality of groundwater resources, development and utilization of groundwater resources and environmental geologic problems, and probed into the main environmental geologic problems in Hainan Island. [Results] The average annual groundwater resources of Hainan Island is about 132.05 billion m3/a. Haikou city has the largest groundwater resources (the multi-year average is 11.33 billion m3/a), and Changjiang county has the smallest groundwater resources. The groundwater quality of Hainan Island was mainly classified as IV-V grade, and the overall water quality was poor. The main influencing factors of water quality were pH, Al and Mn. There were some environmental geologic problems in Hainan Island, such as regional water level decline, seawater intrusion and soil salinization, land desertification, mine geological environment problems. In view of the situation of groundwater resources and environmental geologic problems, some suggestions are put forward, such as carrying out hydrogeology and water resources investigation and monitoring, strengthening the economical and intensive utilization of water resources, and promoting the protection of groundwater ecological environment. [Conclusions] The groundwater resources in Hainan Island are relatively rich, but the water quality is poor, and the environmental geologic problems are prominent. The research results can support the sustainable utilization of water resources, ecological protection and high-quality economic and social development of Hainan Island.
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LIU Chunyan, HUANG Guanxing, JING Jihong, LIU Jingtao, ZHANG Ying, GUO WEI XUAN
DOI: 10.12029/gc20211206002
Abstract:
【Objective】 Groundwater is one of the major water resources to supply water for the production and daily life of human activities in the Huang-Huai-Hai Plain (HP).The deterioration of groundwater environment has become an important factor restricting social and economic development and ecological balance at the conditions of human activities. Understanding the characteristics and driving mechanisms of evolution of groundwater chemistry can provide an important reference for the rational development and utilization of groundwater resources.【Methods】In this paper, the HP is divided into three hydrogeological units including piedmont plain, central plain, and coastal plain. The characteristics and driving mechanisms of evolution of groundwater chemistry in HP in China are studied by using Piper diagram, Gibbs diagram, and principal component analysis.【Results】Results showed that TDS concentrations in groundwater increased gradually from piedmont plain to coastal plain, and groundwater was evolved from freshwater to brine via brackish water and salt water. Groundwater in the study area was from 44 hydrochemical facies in the piedmont plain increased to 74 hydrochemical facies in the central plain, and then decreased to 22 hydrochemical facies in the coastal plain. Among them, the hydrochemical facies of groundwater in the piedmont plain were dominated by HCO3-Ca·Mg and HCO3-Ca, and was mainly controlled by a 4-factors model, by contrast, groundwater chemistry in the central and coastal plains was controlled by two 3-factors models, respectively. 【Conclusions】 The chemical characteristics of groundwater in the HP are obviously zonal, and the hydrochemical facies of groundwater from the piedmont plain to the coastal plain was evolved gradually from HCO3 facies to HCO3·SO4 facies, HCO3·Cl facies, SO4 facies, as well as SO4·Cl facies, and finally convert to Cl facies. The groundwater chemistry in the study area is mainly controlled by a variety of natural factors such as rock weathering, evaporative concentration, cation alternate adsorption, and seawater intrusion on the spatial aspect, and is obviously affected by various human activities (e.g., groundwater overexploitation, land use change, domestic sewage, fertilizers, and animal manure) on the time aspect.According to the different chemical characteristics of groundwater and the impact of human activities in the areas from piedmont plain to coastal plain, the management and control suggestions on the development and utilization of groundwater resources in the HP are put forward.
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Li Wenpeng, Shi Xiaolong, Liu Jianzhang, Chen Shuang, CAI Kui, Song Zefeng
DOI: 10.12029/gc20211126003
Abstract:
Aiming to understand the stability of heavy metal pollution, 100 surface soil samples were collected in farmland soil around the industrial zone. Pb, Cr, As, Zn, Cd, Cu and Hg were analyzed the total concentration, speciation and clay mineral. The heavy metals of farmland soil around Wuji Tannery, Xinji tannery, Handan and Wuan Metallurgy, iron and steel, Guangping chemical plant and Neiqiu chemical plant pollution degree, stability and health risk of soil and wheat were evaluated by using single factor index method, soil mineral evaluation method and health risk assessment model. The results showed that Cr in Wuji tannery soil, Hg in Neiqiu and Guangping chemical Plant and Cd and Hg in Wuan Metallurgy were highly polluted. There was a significant correlation between heavy metals mainly in residual and clay minerals. Soil had high retention for Cd, Ni, Hg and Cu. however, low retention for Pb and As. And Two soil samples from Wuji exceeded the Cr capacity of clay minerals. Human health risk assessments showed that soil exceeded a non-carcinogenic risk (1.02) to children by ingested as orally and skin. However, the cancer risk index with wheat as intake medium exceeded the tolerance limit (1×10?4) for adults (5.16× 10?4) and children (6.44 ×10?4). Therefore, residents living on wheat as staple food in industrial areas should pay more attention to Cd content in wheat.
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Li Juan, Wang Shengjian, Tian Yukun, Zhou Hui, Liu Ce, Xue Zongan
DOI: 10.12029/gc20210407003
Abstract:
【Objective】 The brittleness of shale reservoir is one of the parameters reflecting the fracturing quality of shale gas reservoir, which has an important influence on the degree of difficulty of fracturing and the shape of fracture network. 【Methods】 In order to accurately evaluate the brittleness characteristics of Niutitang Formation shale reservoir in Western Hubei, systematic sampling, whole rock mineral and clay content test, main and trace element content test, acoustic mechanics joint test and other analytical tests were carried out on five wells in the south wing of Huangling anticline in Western Hubei. The quantitative evaluation of shale brittleness was carried out by cluster analysis and principal component analysis. 【Results】The results show that tThere is a close relationship between minerals and rock brittleness, and the cluster analysis method can quantitatively characterize the effective brittle mineral composition and non-effective brittle mineral composition in shale; The comprehensive quantitative evaluation formula of brittleness index based on rock mechanics, mineral composition and element composition is established by using principal component analysis method, which overcomes the limitation of single method and forms the brittleness index profile of Niutitang Formation shale section in Western Hubei. 【Conclusions】The results of microseismic monitoring and fracturing show that the newly established brittle index profile can accurately indicate the high brittle layer of shale, and the fracturing effect is good. 【Key words】Key words: shale brittleness; mineral composition; mechanical parameters; elements; statistical analysis; geological survey project 【Highlights】Overcoming the limitation of a single method, a brittleness index model is established by using a variety of geological factor mathematical models; The shale brittleness is quantitatively evaluated and tested in practice.
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Li Hui, Qian Yong, Han Zhantao, Song Le, Zhang Wei, Ma Lisha
DOI: 10.12029/gc20220302001
Abstract:
[Objective] Organic pollutants, such as chlorinated hydrocarbons and BTEX, have a major threat to the groundwater quality in our country. Natural attenuation monitoring plays an important role in the remediation technologies of contamination sites. The study of natural attenuation monitoring will be conductive to promoting the development of contaminated site control and remediation. [Methods]In order to study the natural attenuation of 1,2,3-trichloropropane (TCP) and benzene in different aquifers groundwater, the 3-year monitoring data of TCP, benzene, oxidation reduction potential (ORP), nitrate (NO3-) and biodiversity in an organic contaminated site has been collected and analyzed. Natural attenuation capacity of the pollution source area of the site was calculated using first order decay dynamics equation. [Results]The results showed that the natural attenuation of TCP and benzene occurred in the aquifer, and ORP values of phreatic and confined aquifer groundwater were -225~-57 mV and -182~-3 mV, respectively, which meant medium-high reducing environment, and anaerobic biodegradation of organic pollutants could be happened. Moreover, the effect of micro-biological degradation was stronger in the pollution source area and phreatic aquifer groundwater than that in non-pollution source area and confined aquifer, and the degradation rates of TCP and benzene in the phreatic aquifer of MMW02 monitoring well were 80.00% and 77.88%, respectively. The attenuation rate of TCP and benzene were 0.0018 d-1 and 0.0016 d-1 in phreatic aquifer, and 0.001 d-1and 0.0015 d-1 in confined aquifer. [Conclusions] Natural attenuation by microorganisms exists obviously in the groundwater contaminated by organic pollutants, but the decay rate is lower. The remediation time of the site will be longer by natural attenuation simply. Therefore, the effective remediation system for organic contamination in the groundwater should be established by the combination of natural attenuation with other technologies.
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li fenqi, Zhang shizheng, li jun, liu han, gou zhengbin, qin yadong
DOI: 10.12029/gc20201214001
Abstract:
This paper reports depositional characteristics of deep?water debris flow of Lagongtang Formation in Nagqu area, Tibet, and points out that it is significant for its controlling factors, depositional process analyzed and depositional model proposed to improve marine theories of gravity flow, to assess petroliferous basins. The debris flow deposit consists of gravel debrites in its lower and sandy one alternating with muddy one in its upper, and soft depositional deformation structures with varying types, scales are developed in it like soft depositional deformation folds, boudinages and soft dual structures. And many slumps and slides are identified in the gravel? and sandy debites. The research shows that along with Mugagangri Group gradually being exposed and denuded in Middle Jurassic, a delta was developed at the tectonic transition from Bangong Co?Nujiang suture zone to Lhasa blok after closure of Bangong Co?Nujiang ocean, forthurmore, it laid a material foundation for the formation of gravity flow deposits of Lagongtang Formation. Futhurmore, the main delta river turned into a canon channel, along with the junction zone thrusting southwards and delta lifting continuously on it. Loose deposits resulted from unconsolidated sediments of the delta collapsed in the channel steep bank flows towards basin along the channel under self?gravity. The debrites diversion took place under the influence of several factors such as terrain when it passed by the mizoguchi, and 2 sub-debrites formed and deposited frozenly at last.
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kongxiangke, liyi, wangping, hanzhantao, liushenghua, zhangzhaoji, wangyanyan
DOI: 10.12029/gc20220312001
Abstract:
[Objective]This study is aimed to study the effects of characteristic pollutants (Cr(III), salinity, organic matter) in tannery sludge leachate on NH4+-N transformation and microbial community structure in soil. [Methods]The transformation of NH4+-N to NO3--N in soil was studied through soil cultivation experiments under different pollution conditions, and the high-throughput sequencing is used to analyze the composition and structure characteristics of microbial community in soil. [Results and Conclusions]The results show that the characteristic pollution components in the tannery sludge leachate inhibit the nitrification process of NH4+-N in the soil, and the influence factors are sorted as follows: Cr(III)>saltness>organic matter. The exogenous Cr(III) pollution has a significant inhibitory effect on the transformation rate and amount of NH4+-N, whereas the saltness and organic matter only delay the start time of nitrification and reduce the nitrification rate in soil. With the increase of Cr(III) content from 100 mg/kg to 250 mg/kg, the transformation amount of NH4+-N decreased from 94.23% to 19.38% after 90 days of culture. The high Cr(III) and salinity in the leachate have a significant impact on the microbial community structure and distribution in the soil at the initial stage of pollution. With the decrease of the bioavailability of Cr(III) and the enhancement of microbial adaptation in soil aging process, the microbial community structure and composition in Cr(III), salinity, and organic matter contaminated soils become similar, and the abundances of nitrifying bacteria (Nitrosospira, Nitrosomonas and Nitrosospira) also have an obvious increase. The results of RDA analysis show that the main characteristic factors affecting the evolution of microbial community structure in tanning contaminated soil are: Cr(III) (R2=0.53, P<0.01), NH4+-N (R2=0.59, P<0.005) and NO3--N (R2=0.53, P<0.01).
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Kong Jiahao, Zhang Guanlong, Xu Shumei, Wangjinduo, Zeng Zhiping, Wang Qianjun, Ren Xinchen, Wu Xiangfeng, Shu Pengcheng, Ma Huilei, Cui Huiqi
DOI: 10.12029/gc20220322001
Abstract:
Che-Mo Synsedimentary paleouplift in Junggar basin is an important geomorphic unit that affects the structural style and reservoir distribution characteristics of Jurassic. At present, the geometry, distribution range, evolution stage and formation mechanism of Che-Mo paleouplift have been deeply studied. Based on the logging data and seismic data of 41 wells in the abdomen of the basin, this paper makes a detailed analysis and isochronous comparison of Jurassic sand body and stratigraphic structure, and focuses on the synergistic evolution between the phased development of Che-Mo paleouplift and the orogenic belt around Junggar basin, especially Bogda mountain, and its influence on the basin boundary and sedimentary pattern. The formation and evolution of Che-Mo paleouplift in Jurassic not only affected the sedimentary landform of the basin, but also significantly changed the basin boundary and provenance pattern, and led to significant changes in sedimentary system, stratigraphic structure style and distribution law. These changes will have an important impact on sand body distribution and reservoir distribution. The evolution of Che-Mo paleouplift can be divided into three stages: initial development stage, rapid uplift stage and post uplift denudation stage. The initial development stage of Early Jurassic Che-Mo paleouplift has no or little influence on the distribution and structural style of Badaowan Formation and Sangonghe formation. The study area is supplied by Zhayier mountain in the northwest and Kelameili mountain in the northeast, mainly forming braided river delta sedimentary system; The Middle Jurassic was the rapid uplift stage of Che-Mo paleouplift. In addition to the source supply of Zhayier mountain in the northwest and Kelameili mountain in the northeast, Bogda mountain also rose out of the water at the same time and began to supply the source, resulting in significant changes in basin boundary, stratigraphic distribution and structural style, resulting in large-area overlap of the first and second members of Xishanyao Formation, loss or denudation of the third members of Xishanyao Formation, The sedimentary system combination of Braided River Delta and beach bar is formed; The uplift of Che-Mo paleouplift in late Middle Jurassic and late Jurassic resulted in the denudation loss of Toutunhe Formation and Qigu formation, forming a regional unconformity with Cretaceous.
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JIANG Yuehua, CHEN Lide, XIANG Fang, zhu jinqi, GONG XÜlong, GUO Shengqiao, YOU Wenzhi, ZHOU Quanping, NI Huayong, WANG Donghui, LIU Guangning, MA Teng, SU Jingwen, YANG Hai, LIU Lin, CHENG Heqin, JIN Yang, ZHANG Hong, YANG Hui, MEI Shijia, QI Qiuju, LÜ Jinsong, HOU Lili
DOI: 10.12029/gc20220605001
Abstract:
This paper is the result of geological environment survey engineering. [Objective] The formation and evolution of the Yangtze River and the recurrent flood disasters in the middle and lower reaches of the Yangtze River are the key scientific problems to be solved urgently. [Methods] By using alluvial fan genetic theory, Combined sedimentary facies profile correlation method, lithofacies paleogeographic analysis, high-precision dating technology, remote sensing method and so on, From the perspective of the basin, the genesis of gravel layers and lithofacies paleogeographic characteristics along the middle and lower reaches of the Yangtze River, planation surface and terrace characteristics of the Three Gorges and the genesis of the great turn of Yangtze River in Shigu, Yunnan in the upper reaches of the Yangtze River are analyzed. [Results] The understandings of the east-west transconnection time of the Yangtze River at the turn of early-Middle Pleistocene (750,000 years ago) and the Holocene river lake evolution pattern of "one River (Yangtze River) and four lakes (Yunmengze, Peng Lize, Dongting lake and Poyang Lake)" in the middle reaches of the Yangtze River the are put forward. The present situation and influencing factors of flood disaster in the middle and lower reaches of the Yangtze River in modern times under the natural and man-made effects were analyzed, and the evolution law of the Yangtze River and its enlightenment to flood disaster prevention and control were combined. The prevention and control measures of flood disaster in the middle and lower reaches of the Yangtze River including "rebuilding Yunmengze, expanding Dongting Lake and Poyang Lake", " Sand exploiting expansion lake, removing silt and turned into farmland " and relevant geological suggestions for the next step were put forward. [Conclusions] The major adjustment of geological environment in the early and middle Pleistocene was an important reason for the connection of the east and west lines of the Yangtze River. The flood disaster prevention and control in the middle reaches of the Yangtze River should fully consider the evolution law of rivers and lakes. The research results can provide basic support and theoretical basis for the territorial space planning, geological disaster prevention and ecological environment protection and restoration of the Yangtze River Economic Belt/Yangtze River Basin.
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Jiang Gaolei, Wang Naiang, LI Zhuolun, Li Meng, Su Xianbao, Ning Kai
DOI: 10.12029/gc20220304004
Abstract:
[Objective] It is of great significance to understand the distribution pattern of saline mineral deposits in lake basin for the reconstruction of palaeoenvironment and palaeohydrology. However, the studies on mineral distribution for groundwater recharged lake sediments are few, which hinders the climate-environmental reconstruction in arid area. [Methods]The Badain Jaran Desert, located in western Inner Mongolia in a hyper-arid area of China, is characterized by the coexistence of more than 110 perennial lakes and thousands of mega-dunes. More than 90% of the recharge of lakes between mega-dunes is from groundwater. In this study, we analyzed the mineral assemblage and distribution characteristics of the surface sediments of eight lakes with different salinity in the Badain Jaran Desert. [Results]The results show that: 1) For individual lakes, the distribution pattern of saline mineral deposits is similar to those of lakes with runoff recharge, that is, there are more detrital mineral deposits at the edge of the lake, and the saline mineral deposits gradually increase towards the lake interior, and the mineral types gradually change from carbonate to sulfate and chloride. 2) The mineral composition of the sediments near the lake edge is more easily affected by the variation of lake water level and area, while the sediments near the lake center may be affected by the water depth and the groundwater recharge. 3）The shallow lakes are well mixed and are not easily affected by the stratification of lake salinity and water temperature, and the replenishment of fresh water at the bottom. Moreover, the total content of salt minerals has a good linear relationship with the salinity of lake water. [Conclusion] The changes of saline mineral assemblage and its content in the lakes recharged by groundwater can well reflect the changes of lake salinity and can be used as a proxy of climate-environmental reconstruction in desert areas. This study will provide an important basis for the reconstruction of palaeohydrological information using lake saline deposits in arid areas of China.
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hejianhua, Cao Feng, Deng Hucheng, Wang Yuanyuan, Li Yong, Xu Qinglong
DOI: 10.12029/gc20220107003
Abstract:
The second member of Xujiahe formation of the HC area in the Sichuan Basin has great potential for exploration and development, but it is a typical low-hole and low-permeability tight gas reservoir, which requires in-situ stress refined evaluation to recommend the optimal selection of engineering sweet spots for later vertical fracturing and flat fracturing to increase production. Based on experimental test analysis such as 25 groups of acoustic emission and 13 groups of differential strain, combined with hydraulic fracturing, conventional and special logging data. To analyze the applicability of different experimental test methods in dense sandstone reservoirs by performing a fine-scale evaluation of the magnitude of in-situ stress and identified layers and sweet spots conducive to engineering modifications. The results of the experimental tests the second member of Xujiahe formation in the HC area showed that the maximum horizontal principal stress values ranged from 50.77 to 75.65 MPa, with a mean value of 59.71 MPa; the minimum horizontal principal stress values ranged from 45.37 to 54.31 MPa, with a mean value of 49.31 MPa; and the vertical stress values ranged from 48.11 to 65.62 MPa, with a mean value of 56.53 MPa. The comparison of the three-way stress relationships between the minor layers indicates that the second member of Xujiahe formation is in a strike-slip stress state. The dense sandstone in the second member of the Xujiahe formation is more homogeneous, the acoustic emission test results are more inaccurate. The results of the differential strain test are in better agreement with the results of the in-situ stress magnitude interpretation, making the test method more suitable for more homogeneous sandstone formations. In combination with the magnitude of in-situ stress, it is recommended vertically that the more favorable combination of compartments, upper middle of the second subsection of Xu-II, be selected as the target layer for fracturing. To achieve a better volumetric seam network fracturing transformation, it is recommended to avoid areas near faults with a large horizontal in-situ stress difference factor in the plane. The area of HC102-HC111 well in the central part of the HC area, where high-quality reservoirs are developed and the horizontal stress difference factor is relatively small, should be selected.
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HAO Xiudong, LAO Yueying, OUYANG Xuhong, JIANG Xingyu, WANG Fu, TIAN Lizhu, SHI Peixin, CHEN Yongsheng, WANG Hong, LI Jianfen, SHANG Zhiwen
DOI: 10.12029/gc20210804001
Abstract:
Objective Microfossils, especially pollen, spores, and dinoflagellate cysts, as direct indicators or proxies, provide significant information on geological environment. Therefore, palynological analysis has an important role in restoration and reconstruction of vegetation history and sea-level fluctuations, which provides information from the sediment cores, especially in alluvial coastal plain regions. Methods In this study, we carry out analyses using detailed palynological records of pollen, spores, freshwater algae, marine dinoflagellate cysts, and foraminiferal organic linings from Borehole HLL01 on the southern coastal plain of Laizhou Bay, Bohai Sea, northern China. Results and Conclusions The results provide valuable information on vegetation history and sea-level fluctuations since the Late Pliocene. Large amounts of terrestrial herb pollen (75.13%; mainly composed of Chenopodiaceae, Artemisia and Poaceae) were identified at Borehole HLL01, suggesting that coastal steppes flourished in the study area and its adjacent areas, and a cold and dry climate than the present during the Late Pliocene to Early Pleistocene, ca. 6.8-1.6 Ma. After that, the steppe areas began to shrink, and the transition of coastal steppes to forest grasslands occurred in the Early-Middle Pleistocene, ca. 1.6-0.6 Ma, indicating a warm and humid climate. A sharp increase in freshwater algae indicates that large rivers’ discharge had been injected into the study area, or large lakes were formed. Afterward, relatively cool and dry climatic conditions appeared, with little precipitation, and a relatively significant transgression event revealed by dinoflagellate cysts and foraminifera organic linings, and forest grassland vegetation was distributed in the study area and its adjacent areas, during the Middle Pleistocene to Holocene, ca. 0.6-0.004 Ma. Highlights ? Pollen, spores, freshwater algae, marine dinoflagellate cysts, and foraminiferal organic linings from the southern coastal plain of Laizhou Bay were investigated. ? Three major phases shown by palynological results were corresponding to the vegetation evolution and sea-level fluctuations
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gongwenqiang, Su Kui, zhangzhen, gaowei, weiliyong, zhaochao, wangate, hejiale
DOI: 10.12029/gc20210412001
Abstract:
There are many disputes about the the age and prowenance of Dacaotan Formation, With clastic rocks of the Upper Devonian Dacaotan Formation at Qiagai area in the West Qinling Orogenic belt as the study object, the authors used LA-ICP-MS zircon U-Pb isotope geochronological method to explore the age and prowenance of Dacaotan Formation. The results show that the detrital zircon ages can be divided into 4 groups: (1)The Archen-Paleoproterzoic(2232-3258Ma); (2)The Mesoproterzoic(1018-1791Ma); (3) The Neoproterzoic(544-999Ma); (4)The Early Paleozoic(417-519Ma). Among which, the Early Paleozoic(417-519Ma) ages data possess the largest proportion, accounting for about 39.6% of the total data. The lesser is the Neoproterzoic(544-999Ma) ages, about 37.3%. The other two groups ages possess a smaller proportion. Preliminary analysis show that, the provenance source of Dacaotan Formation were much more complicated and characterized by obvious diversity and periods, derived from northern margin of western Qinling orogenic belt, the eastern part of the Qilian orogenic belt and the basement of North China plate. The predominant part among them was the active magmatic arc produced by collision orogen, which come from the northern margin of western Qinling orogenic belt and Qilian orogenic belt during the Caledonian period.
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FU Changchang, LI Xiangquan, ZHANG Wenjing, CHENG Xu, BAI Zhanxue, LI Jinqiu
DOI: 10.12029/gc20220426002
Abstract:
Abstract: This paper is the result of hydrogeologic survey engineering. [Objective]Budongquan spring is in the region of Hoh Xil on the northern Qinghai–Tibet Plateau. It is a typical sub-surface spring with discharge that ascends to the surface through taliks in the permafrost. It is an important water supply for the Qinghai–Tibet railway and the construction of small towns along the railway. Therefore, it is very important to understand its formation and water characteristics. [Methods] In this paper, we evaluated spring water quality using the single index evaluation method. We analyzed water storage, circulation, and sources of main chemical components by examining the local geology, environmental isotopes, and hydrochemistry. [Results] Results show that Budongquan spring water quality is in class V throughout the year. It is in class V in terms of total hardness, SO42?, and Cl?, and in class I–II in terms of toxicological and heavy metal indices. Nearby glacier meltwater and river water are in class I–II. The spring is mainly recharged by glacial meltwater from the southern slope of Kunlun Mountains, atmospheric precipitation, and surface river water. Average cycle length is less than 5–10 years. Groundwater flow follows the talik zone along the northeast-trending active normal faults. Budongquan spring is formed by the surfacing of groundwater that is blocked by the west-northwest-trending active reverse faults. Its chemical composition is mainly determined by evaporation, and presence of and interaction with magnesium salts and carbonate rocks. [Conclusions] To meet standards for drinking water, we recommend mixing spring water with river water at a ratio of 1:2.
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Fang Jing, Wang Fu, SHANG Zhiwen, YAN Xia, KANG Qinwei, QU Yinghui, WANG Tianjiao, LIU Yufei
DOI: 10.12029/gc20210725002
Abstract:
【Objective】In order to study the diatoms indication significance to the sea level and the maximum transgression range, 【Methods】this paper analyzes the diatoms and AMS 14C dating data from three 30m deep drilling cores collected near Chenier V of northern Cangzhou, Bohai Bay. 【Results】The results show that diatoms are rare in these drilling cores, and there is only one diatom rich layer in each core, which is composed of peat and humus gray clay. The thickness of the layer is 10 cm to 60 cm, and thinner from seaward to landward. 7473 cal BP, site of DC01 changed from a sea water influenced swamp environment to a fresh water swamp environment, indicating a relative sea level lower than -6.37m; 7513 cal BP，site of QX02 was transformed from saltmarsh environment (zone I) to sea water influenced shallow swamp, then to salt marsh environment (zone III), The elevation of the boundary between zone I and zone II indicating a relative sea level of -6.68m. 7836 cal BP, site of QX01 was transformed from a freshwater swamp (zone I) to a salt marsh environment (zone II). The boundary between zone I and zone II indicating a relative sea level of -7.68m.【Conclusions】Relative sea level raised ~1m during these ~350 years, and the sea water affected the area to the west of the Chenier V. The salt marshes and freshwater swamps were the main environmental types near the transgression maximum in the Early-Mid Holocene. Under the background of modern sea level rise, marshification is a major environmental problem that modern coastal areas must face.
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DUAN Ming, ZHANG Bo, TANG Chao, XU Zenglian, WEI Anjun, JIANG Zhiquan
DOI: 10.12029/gc20210807001
Abstract:
This study aims to ascertain the petrological, mineralogical, and geochemistrial signatures of the sandstone (mudstone) of the uranium bearing target layer in the Erennur Sag, Erlian Basin, and to discuss uranium mineralization. Research methods include field geological cataloging, polarized light microscopy, electron probe spectroscopy analysis, major trace elements, environmental geochemistry, and uranium valence analysis. The research results show that: (i) Uranium minerals exist in the form of adsorbed and independent uranium minerals, often co-existing (associated) with carbon chips and pyrite, with occasionally with presence of sphalerite.. (ii) The ore exhibits the characteristics of high organic carbon, S and CO2. The average U6+/U4+ of mudstone is 1.01, and the average U6+/U4+ of sandstone is 0.57. (iii) The CIA value of sandstone (mudstone) is 50.83 to 66.34. The characteristics of rare earth elements are consistent with those of granite in the erosion source area, The characteristics of main and trace elements all show that there is obvious water-rock interaction in the late sedimentation-diagenesis stage. The following conclusions can be drawn: (i)The Hercynian granite is the dominant source of the sandstone (mudstone) of the Saihan Formation. The sedimentary environment is a semi-arid-semi-humid paleo-climate. (ii) Adsorption and oxidation-reduction are the main mechanisms of uranium enrichment in the study area. Mudstone-type uranium enrichment is mainly in the form of adsorption, while sandstone-type uranium enrichment is mainly in the form of oxidation-reduction. (iii)The deep fluid may have participated in the mineralization.
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Chen Xiaohong, Tian Wei, Li Xubing, Li Hai, Zhang Baoming, Zhang Guotao
DOI: 10.12029/gc20210816001
Abstract:
On the basis of natural gas exploration in Xiangzhong Depression, the Yangjiashan anticline with active shallow natural gas was selected to carry out shale gas investigation. The results show that the shale in the lower part of Lower Carboniferous Tianeping Formation has large thickness and high gas content, which is of great significance for shale gas exploration. Based on the systematic study on the genesis of organic-rich shale and the physical properties of shale gas reservoirs in Tianeping Formation, combined with the thermal evolution simulation of medium-high maturity shale gas reservoirs in semi-open environment, the following understandings are obtained: (1) The organic-rich shale of Lower Carboniferous Tianeping Formation is the sedimentary product of seawater stratification and seabed anoxia caused by the violent climatic fluctuations in the Early Carboniferous in Lianyuan area, and has the characteristics of wide distribution and large thickness. (2) The extensive and intense Mesozoic magmatic events in central Hunan led to the obvious increase of shale maturity near the rock mass, which has changed the deep thermal evolution model of shale organic matter maturity increasing with burial depth, and have important influence on the evolution process of hydrocarbon generation and shale gas reservoir of the Lower Carboniferous organic-rich shale in Lianyuan area. (3) The experimental results of thermal evolution simulation of medium and higher maturity shale reservoir under semi-open system show that the crude oil generated by thermal decomposition of organic-rich shale will fill various pores of shale reservoir, resulting in the deterioration of physical properties of the reservoir. However, after entering the gas generation stage, the bedding fractures and organic pores of shale become wider and increase with the increase of maturity, which makes the physical properties of the reservoir significantly improved.(4)The organic-rich shales of the Lower Carboniferous Tianeping Formation in the Lianyuan Sag experienced the early Carboniferous to middle Triassic plutonic thermal evolution stage, the late Triassic to Cretaceous magmatic thermal evolution stage, and the oil and gas adjustment and reconstruction caused by two regional folds and uplifts in the Indosinian and early Yanshanian. Shale gas enrichment in Tianeping Formation is the result of favorable facies zones controlling reservoir and tectonic-magmatic activity controllingSaccumulation. The low concealed structures of the foot wall of the thrust nappe fault developed in Yanshanian period may be the most favorable exploration areas. S
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CHEN Shuwang, SUN Shouliang, ZHANG Tao, Barry P. Kohn, Andrew Gleadow, LIU Yan, Ling Chung, LI Yongfei, DING Qiuhong
DOI: 10.12029/gc20210407001
Abstract:
【Objective】The tectono-thermal history of the Cretaceous fault basins in the Songliao peripheral area had not been well explored. The Xiushui basin is a new exploration area with high hydrocarbon potential in the southern part of the Songliao peripheral area. The reconstruction of the burial and thermal history of the Xiushui basin has become an important issue for hydrocarbon exploration in this area. 【Methods】Based on five samples from the well LFD1 in the Xiushui Basin, burial and thermal history as well as hydrocarbon source rock evolution history of the Xiushui basin were studied using apatite fission track methods. 【Results】The results show that the Xiushui basin reached its maximum burial depth in the late Early Cretaceous, and then uplift continued and denudated about 2000m. The terrestrial heat flow value increased linearly with time during the initial subsidence period, reaching the maximum value of about 100.5 mW/m2 at about 120Ma, and then experienced a three-stage cooling process, i.e., rapid cooling, then slow cooling, and finally rapid cooling. The heat flow pattern is similar to and comparable with the adjacent Zhangqiang Depression and the Songliao Basin. 【Conclusions】The reconstruction results of the burial and thermal history of the well LFD1 indicate that the hydrocarbon source rocks of the third member of the Yixian Formation entered the oil generation window around 90 Ma, and thereafter, due to the uplift and cooling of the formation, the thermal evolution of the source rock ceased, thus remain unchanged to date. 【Key words：】Burial history; Thermal history; Apatite Fission Track; Xiushui basin; southern Songliao Basin; oil-gas geological survey enginnering 【Highlights：】 1. Burial and thermal history as well as hydrocarbon source rock evolution history of the Xiushui basin were studied using apatite fission track methods for the first time, which lays a foundation for further oil and gas exploration. 2. The regional paleothermal flow shows a trend which the Songliao basin is the highest and gradually decreases to the south, and the reasons for this trend are discussed.
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caowengeng, wangyanyan, zhangdong, sunxiaoyue, wenaixin, najing
DOI: 10.12029/gc20221128002
Abstract:
【Objective】With the improvement of industrialization, the discharge of industrial wastewater containing heavy metals (such as arsenic, copper, chromium, cadmium, nickel, zinc, lead, mercury and manganese) is gradually increasing. Due to its non-biodegradability and long half-life, heavy metals in wastewater cause serious pollution in groundwater, surface water, soil and crops, seriously endangering the health of human beings, animals and plants. Therefore, it is necessary to remove these toxic heavy metals from industrial wastewater.【Methods】Based on the current status of heavy metal pollution in industrial wastewater, the current status and progress of heavy metal treatment in industrial wastewater are analyzed by comprehensively considering removal efficiency, treatment cost, sludge output, recyclability and other factors.【Results】This paper presents the research of main technologies on heavy metals removal from industrial wastewater. The internal mechanism, influencing factors (pH, temperature and heavy metal concentration) and their advantages and disadvantages of each technology are summarized, and the development trend of heavy metal removal technology in industrial wastewater is prospected in order to provide meaningful reference for the comprehensive treatment of industrial wastewater containing heavy metals.【Conclusions】Various heavy metal removal technologies have broad prospects on heavy metal treatment, coming with some drawbacks. Conventional physical and chemical methods have problems such as high sludge production, low removal efficiency and high energy consumption, while biological methods have strong dependence on pH and temperature, and high demand for energy and maintenance. Combined process is a feasible method to improve the removal efficiency of heavy metals. Research and development of new natural adsorbents, membrane technology and biotechnology, and strengthening the comprehensive application of various technologies are effective ways to removing heavy metal from industrial wastewater.
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Ge Mingna, Bao Shujing, Shi Dishi, Zhang Liqin, Lin Yanhua, Wang Ting
DOI: 10.12029/gc20210923001
Abstract:
【Abstract】： 【Objective】To study the pore structure characteristics of Niutitang Formation shale in Southeast Guizhou and its influence on shale gas enrichment, avoid unfavorable factors, and provide suggestions for shale gas exploration in Southeast Guizhou. 【Methods】Multi-scale characterization of the shale micro-nano pore structure is carried out by means of focused ion beam scanning electron microscopy (FIB-SEM), FE-SEM, and nitrogen adsorption. Combined with the hydrocarbon generation and burial history of the Niutitang Formation shale in the study area, the relationship between tectonic movement and pore structure is studied, and its control effect on shale gas enrichment is analyzed. 【Results】The Niutitang Formation shale mainly develops millimeter-scale micro-cracks, micron-scale pyrite intercrystalline pores and nano-scale organic pores, mainly ink bottle-shaped pores and slit pores with a flat plate structure, and the pore structure is complex. Combined with the results of FIB-SEM three-dimensional reconstruction, organic matter accounts for a relatively high proportion of shale, with a porosity of 0.04-2.48% and a contribution rate of 14%-96% to the total porosity. The pyrite crystals co-existing with organic matter Pores are the main type of pores that communicate fractures , the shale gas in this area is dominated by undersaturated adsorbed gas, and the free gas content is low. 【Conclusions】A large number of structural fractures in the Niutitang Formation shale have connected organic matter pores and pyrite intercrystalline pores, and changed the original pore structure, causing the in-situ accumulated shale gas to escape along the fractures ，which is a key factor in the low gas content of the shale of the Niutitang Formation. Finding areas with moderate thermal evolution and well-preserved structures is a favorable direction for shale gas exploration on the periphery of paleo-uplifts.
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chenyuanming, gao zhi peng, guohuaming, li wei, chen zongliang, wang xi, ma xuemei
DOI: 10.12029/gc20180915003
Abstract:
The Tailai basin is one of the known hydro-geological units containing strontium mineral water. The study on the genesis and distribution of strontium mineral water in the Tailai Basin can provide direction for the investigation and development of strontium-bearing mineral water in the future. On the basis of the division of different water-bearing rock groups in the Tale basin, water samples such as Karst water, fissure water, porosity water and surface water were collected in the basin. The hydrogeochemical characteristics of four types of water and the evolution of mineral water containing strontium were studied by mathematical statistics, ion ratio coefficient, correlation analysis, isotope analysis and hydrogeochemical simulation. The results showed that the four types of water showed the characteristics of calcium-rich, magnesium-rich, low-sodium, low-potassium and weak alkaline, and the main hydrochemical type of them is HCO3.SO4-Ca.Mg. The four types of water are closely linked and affected by some degree of evaporation and concentration. The Sr2+ concentration of Karst water and pore water in the central basin was high, while the concentration of bedrock fissure water and surface water was relatively low. The enrichment of Sr2+ in groundwater is mainly controlled by weathering dissolution of calcareous minerals such as calcite and dolomite, and affected by evaporation concentration to a certain extent, while the effect of cation exchange is relatively small.
The Online First column displays articles that have been accepted by Geology in China through peer review. These articles are currently in the redaction process and have not yet determined the volume and page number. And the final printed version of the article may be slightly different in individual formatting or text expression, but the overall content of the article is completely consistent. The copyright of its contents is protected by relevant laws and regulations.
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Chenyang LI, Xinchun WANG, Chunzhen HE, Xuan WU, Zhaoyu KONG, Xiaolei LI
2019,46(S1):1-10, DOI: 10.12029/gc2019Z101
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As the only one of its kind, China National Digital Geological Map (Public Version at 1:200000 scale) Spatial Database (CNDGM-PVSD) is based on China's former nationwide measured results of regional geological survey at 1:200 000 scale, and is also one of the nationwide basic geosciences spatial databases jointly accomplished by multiple organizations of China. Spatially, it embraces 1163 geological map-sheets (at scale 1:200 000) in both formats of MapGIS and ArcGIS, covering 72% of China's whole territory with a total data volume of 90 GB. Its main sources is from 1:200 000 regional geological survey reports, geological maps, and mineral resources maps with an original time span from mid-1950s to early 1990s. Approved by the State's related agencies, it meets all the related technical qualification requirements and standards issued by China Geological Survey in data integrity, logic consistency, location accuracy, attribution fineness, and collation precision, and is hence of excellent and reliable quality. The CNDGM-PVSD is an important component of China's national spatial database categories, serving as a spatial digital platform for the information construction of the State's national economy, and providing information backbones to the national and provincial economic planning, geohazard monitoring, geological survey, mineral resources exploration as well as macro decision-making.
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MAO Jing-wen, ZHOU Zhen-hua, FENG Cheng-you, WANG Yi-tian, ZHANG Chang-qing, PENG Hui-juan, YU Miao
2012,39(6):1437-1471, DOI:
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Abstract：Triassic tectonic evolution in China is characterized by high intensity and wide influence. However, the metallogenic study related to the major Triassic tectonic events has obviously been lagging behind. This paper preliminarily and systematically discusses the space-time distribution and basic characteristics of the large scale Triassic mineralization in China based on the latest research achievements. Triassic deposits in China are distributed mainly in the two main Triassic orogenic belts of the Kunlun-Qinling orogenic belt and the Red River - Ailaoshan orogen belt and their adjacent regions; Besides, there are a series of polymetallic deposits developed in the three intraplates of southern China, northeastern China and Xinjiang area. Major types of Triassic deposits mainly include： ① Cu-Ni sulfide deposits related to basic-ultrabasic rock; ② porphyry Cu-Au, Cu-Mo, Mo deposits, skarn Cu-Pb-Zn, Cu-Fe, Sn, W deposits and vein-type Au deposits related to intermediate-acid rocks and acidic plutons; ③ pegmatite-type rare metal deposits related to high temperature gas-fluids; ④ orogenic Au deposits related to tectonic-hydrothermal activities in the orogenic process; ⑤ MVT Pb-Zn deposits related to basinal fluids in the orogenic process; ⑥ carbonated vein-type Mo deposits related to mantle fluids. Most of the Triassic deposits in the Kunlun-Qinling orogen belt were mainly formed in collisional stage, or in the post-collision setting. In East Qinling area, the Triassic deposits are dominated by Mo, Au, with the formation ages mainly concentrated in 233-221Ma. In contrast, Au deposits and Pb-Zn deposits of Triassic are widely distributed in West Qinling area, Au deposits are distributed along the NW-trending brittle-ductile shear zones, and Pb-Zn deposits are largely concentrated in the two targe basins of Xicheng and Fengtai, whose metallogenic epochs are mainly in the Late Triassic (232-214Ma). In East Kunlun area, newly discovered Cu-Mo-Fe polymetallic deposits were formed in 240-210 Ma. Influenced by Neo-Tethys evolution, Triassic metal mineral resources are scattered in the Red River - Ailaoshan orogen belt, mainly distributed in Zhongdian ancient island arc, Yunnan-Guizhou-Sichuan border area in the east of the orogenic belt and Dulong area of southeast Yunnan. In Zhongdian area, the metallogenic ages are concentrated in 228-201Ma and their distribution shows the characteristics of porphyry-skarn Cu deposits in the middle part and porphyry-epithermal Cu-Pb-Zn deposits and Au deposits on both north and south sides. The dating results obtained in recent years indicate that Pb-Zn deposits in Yunnan-Guizhou-Sichuan border area were mainly formed in Triassic. Moreover, a series of Triassic W-Sn deposits have been discovered recently in Dulong area of southeast Yunnan, whose peak age is 214-209Ma. In addition to the two main collision belts, rare metal and W-Sn deposits in South China, rare metal and Mo deposits in Xinjiang, porphyry Mo deposits, Cu-Ni sulfide deposits and vein type Au deposits in Northeast China and its adjacent areas were also formed in Triassic, and all of these deposits were closely related to the collision regime, most Triassic deposits in South China were related to EW-extending tectonic-magmatic systems and derived from the emplacement of aluminum granite resulting from the remelting of thickened crust. The mineralization of Triassic deposits in Northeast China and its adjacent areas, Xinjiang, and some neighboring areas of Mongolia and Russian Altay as well as Siberia were probably related to mantle plume activities.
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LI Xu-bing , ZHAO Can, LIU An, WEI Kai, LI Jitao
2013,40(5):1493-1504, DOI:
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Abstract：This paper divided and depicted in detail two second-order sequences and seven third-order sequences which are regionally well correlatable according to the Ediacaran system, by employing the research method of sequence stratigraphy “from lithofacies to meter-scale cycle,from depositional facies to sequence classification”. With the reservoir as the center, the authors mainly studied the temporal and spatial distribution of source rocks and reservoirs based on sequence framework, and comprehensively considered the matching relationship of source rocks and cover rock affecting reservoir formation. The source-reservoir-cap rock combinations in carbonate rock of the Ediacaran system were divided into 3 types, i.e., boundary type, transgression type and high water type. The findings indicate that the source-reservoir-cap rock combinations associated with sequence boundary in the study area have the most superior initial geological condition, the high water type is usually combined with the karst or boundary type, thus serving as another source-reservoir-cap rock combination with obvious effectiveness.
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QU Cui-xia1, YANG Xing-ke1, HE Hu-jun1, GAO Ping2, SONG Hong-ye3
2013,40(5):1409-1420, DOI:
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Abstract：This paper deals with petrologic and geochemical features and zircon U-Pb isotope ages of the intrusive rocks from Yantan belt in Beishan area，which are mainly composed of quartz diorite, granodiorite, monzonitic granite, K-feldspar granite, granite and granite-porphyry, belonging to high-K calc-alkaline and calc-alkaline series; All the rocks are characterized by enrichment of LREE，depletion of HREE and strong Eu negative anomalies. The trace elements are enriched in LILE(Rb, Th), and depleted in Sr, Nb, Ta evidently. The zircon SHRIMP U-Pb ages of the quartz diorite and granite are (296±4.1) Ma and (294±3.7) Ma respectively，both of the data are consistent within test errors, suggesting that the rocks were formed at the beginning of the early Permian period. An analysis suggests that these intrusive rocks are I-type granite which are indicative of the underplating of the mantle material into the lower crust and the formation of these rocks in the post-collision tectonic environment after the closure of Beishan rift. The result shows that the Beishan rift was closed in the early Permian in the study area.
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GAO Lin-zhi1, LU Ji-pu2, DING Xiao-zhong1, WANG Han-rong2, LIU Yan-xue1, LI Jiang2
2013,40(5):1443-1452, DOI:
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Abstract：In the zircon study of bentonite from the Danzhou Group and overlying strata of the Nanhua System, the authors accurately determined the age of (801±3) Ma for zircon from the Hedong Formation and (778±6) Ma for zircon from the Gongdong Formation. (778±5) Ma is the age of zircon from the Chang’an Formation, which is the bottom of the Nanhuan System, and (661±7) Ma is the age of zircon from Datangpo Formation of the intraglacial period. Some zircon ages of tuff bedding were reported for the first time from the Sibao and Xiajia Groups in Guangxi and Guizhou. In combination of the SHRIMP U-Pb age of the granite (834±4 Ma) which intruded into the Sibao Group (842±13 Ma) and the SHRIMP U-Pb age of (837±7) Ma of Bendong granite, the authors hold that the Sibao Group is Late Neoproterozoic strata below the strata of 820 Ma. These isotopic data are very important for us to redefine the age of the Sibao Group and to conduct regional correlation of strata of the corresponding period as well as to study tectonic evolution. There is an angle unconformity between the Sibao Group and overlying Danzhou Group and a nonconformity between the Danzhou Group and the Nanhuan System, suggesting the existence of three levels of tectonic factor. The revised age column will influence the whole metamorphosed basement in the Jiangnan Orogen and the constraints on the relationship of the cover strata in South China.
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DU Xiao-dong1, 2, ZOU He-ping1, 2, SU Zhang-xin1, LAO Miao-ji1, CHEN Shi-ai1, DING Ru-xing1, 2
2013,40(4):1112-1128, DOI:
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Abstract：The Daoyaoshan-Damingshan area is located in the southwestern section of the Qinzhou-Hangzhou juncture between the Yangtze Block and the Cathayian Block．The study of the early Paleaozoic sedimentary environment and tectonic setting of this area is a key to understanding the geotectonic problems in South China. Major and trace elements of 27 pieces of samples from Cambrian sandstones and mudstones in this area were analyzed and discussed. The samples generally have high ratios of Al2O3/TiO2 ( in the range of 11.95~36.26,20.81 on average) and lower ratios of Rb/Cs（in the range of 13.02~68.27, 32.21 on average） and Cr/Zr（ranging 0.14～1.15,averagely 0.59）. Geochemical characteristics, such as the plots of Ni-TiO2,Th/Sc-La/Sc and La/Th-Hf , indicate that the Cambrian sediments in the Daoyaoshan-Damingshan area were mainly sourced from the upper crustal felsic quartz rocks,with the addition of a small amount of igneous sources and ancient recirculation sediments．The distribution of trace and rare-earth elements and the data of La-Th-Sc,K2O/Na2O-SiO2, δCe,δEu,Tb/Yb,La/Sc,La/Th,Th/U as well as the comparison with different tectonic settings show that the study area belonged to a passive continent-marginal setting. In addition, such evidence as the marks of shallow-sea deposits,the data of sedimentary palaeogeography,regional geology and geochemistry suggests that during the Early Paleozoic there existed no geochemical evidence for the so called “ancient ocean in South China”．
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CHEN Gang1, LI Shu-heng2, ZHANG Hui-ruo2, DING Chao1, YANG Fu1, LEI Pan-pan1
2013,40(5):1453-1465, DOI:
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Abstract：Geochronology of oil-gas accumulation (OGA) is a key research frontier for petroleum reservoir-forming dynamics in the multi-cycle superimposed basin. The OGA timing and stages of the Permian reservoirs in northeastern Ordos Basin (OB) are constrained in this paper by K-Ar dating of authigenic illite (AI) and indirect dating of fluid inclusions (FI) from oil-gas-bearing sandstone core samples of the Lower-Upper Permian period. AI dating results of the Permian samples show a wide time span of 178～108 Ma and a spatial decreasing trend from 178～122 Ma in the south to 160-108 Ma in the north. The distribution of the AI ages generally reveals 2-stage primary OGA of the Permian reservoirs, which were mainly developed in the time spans of 175～155 Ma and 145～115 Ma respectively with 2-peak ages of 165 Ma and 130 Ma. Additionally, the FI temperature peaks of the samples and their projected ages on AFT thermal path of the FI-host rocks not only statistically present two groups with a low and a high peak temperatures in ranges of 90～78 °C and 125～118 °C, respectively corresponding to 2-stage primary OGA processes of 162～153 Ma and 140～128 Ma in the Permian reservoirs; nevertheless, there is also a medium temperature group with the peak of 98 °C in agreement with a secondary OGA process of ca. 30 Ma in the Upper Permian reservoirs. An integrated analysis of the AI and FI ages with the regional tectonic thermal evolution reveals that the Permian reservoirs in the northeast OB mainly experienced 2-stage primary OGA processes of 165～153 Ma and 140～128 Ma during the Mid-Early Mesozoic multi-cycle burial heating processes, and then the Upper Permian reservoirs further experienced 1-stage secondary OGA of ca. 30 Ma in accordance with a critical tectonic conversion from the slow to rapid uplift-cooling process during the Late Cretaceous-Neocene period.
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ZHANG Wan-Yi1, 2, NIE Feng-Jun3, LIU Shu-wen2, ZUO Li-Yan2, SHAN Liang2, YAO Xiao-Feng2
2013,40(5):1583-1599, DOI:
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Abstract：Located in Chagan Obo－Aououte－Chaobuleng area along the southern edge of the Siberian plate, the study area on the western slope of the southern section of the Da Hinggan Mountains metallogenic belt (northern Dong Ujimqin Banner of Inner Mongolia ) is controlled by multiple subduction, collision and connection of North China platform, and characterized by widely exposed Paleozoic volcanic-sedimentary rocks, complex structures, all kinds of intense magmatic activities, and widespread ore deposits and ore spots. The study area has special favorable geological structure and setting for mineralization. On the basis of geological survey, the authors studied geological features of ore deposits and genesis of typical deposits, and summarized metallogenic regularities of this area. The results show that there are many kinds of ore deposits such as iron, silver, copper, lead, zinc, gold, and molybdenum. The δ34S values of typical deposits vary from +1‰ to +8.6‰. The sulfur isotope compositions show different sources. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of different samples vary in ranges of 17.949～18.529, 15.370～15.691 and 37.653～38.460, respectively. The lead isotope compositions indicate that the sources of lead were wall rocks and granites. The main types of ore deposits were skarn deposits and medium-low temperature hydrothermal deposits, which were significantly affected by formation, structure and magma. In general, the wall rocks of metal deposits were Ordovician, Devonian and Carboniferous volcanic- sedimentary rocks. Skarn deposits were formed near the contact zone between the carbonate and granite, while medium-low temperature hydrothermal deposits were formed in argillite and sandstone without carbonate. NE- and NW-trending faults were important ore channels or places for ore storage. The regional ore deposits in the study area were formed in three periods, i.e. Hercynian, Indosinian and Yanshanian. They were closely related to granite intrusions in temporal and spatial distribution.
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SUN Zhong-shi1, LIU Si-chuan1, 2, ZHENG Chang-qing1, TAN Lian2, SUN Li1, LI Juan1, SHI Lu1, CUI Fang-hua1, FAN Si-qi3
2013,40(2):529-537, DOI:
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Abstract：Ore-controlling structure is always one of the difficulties in the study of hydrothermal deposits. With Chaihezhen-Moguqi region of the Da Hinggan Mountains as the study object, this paper puts forward some conclusions on the basis of the 1:250000 geological investigation of. Chaihezhen-Moguqi region. 1. The main ore-controlling structures are Daheishan-Taipingling-Jiguanshan fracture zone and Zalantun City-Haduo River fracture zone, and the formation ages are mainly Hercynian and Yanshanian. 2. Ore-controlling structures mainly show compression, tensile and shear properties, and between the three properties, there existed the conversion between shear and tensile and between shear and torsion, with the principal compressive stress field changing in the directions of E-W, SE-NW to SSE-NNW in succession. 3. The regularities of the main ore-controlling structures, the branching ore-control structures, and the parallel and inclined ore-controlling structures are summarized in this paper. These regularities, the structures as passageways for ore fluids and the ore source were closely related to deep subduction which produced molten magma. These new ideas are of great significance for the detailed study of geological foundation, metallogenic theory and prospecting work in this region.
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WANG Lei, LONG Wen-guo, ZHOU Dai
2013,40(4):1016-1029, DOI:
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Abstract：LA-ICP-MS U-Pb dating was conducted for zircons from four gneissic granites in Yunkai area, which were assigned to Precambrian basement rocks or Neoproterozoic intrusion in 1∶250000 geological survey. The dating yielded 206Pb/238U weighted mean of 443.3±2.6 Ma (sample 1009, Lutou Reservoir in Luchuan City), 445.7 ±2.3Ma (sample 1010, Yuedong in Luchuan city), 441.1±2.0Ma (sample 1012, Xieji in Gaozhou city) and 443.7±1.7Ma (sample 1018, Zhusha in Xinyi city), suggesting that these rocks are Caledonian products rather than Precambrian basement or Neoproterozoic intrusive rocks. In combination with previous studies, the authors hold that these granites probably resulted from partial melting of the Proterozoic materials due to the Caledonian orogeny in South China. These results and recently published data (Caledonian) for the so-called Precambrian basement rocks, such as the crystallization age or metamorphic age of gneissic granite and gneiss, indicate that Yunkai area has undergone extensive reformation by the Caledonian orogeny. Actually, the Precambrian basement of Yunkai area mainly consists of gneissic rocks and meta-sedimentary rocks, which serve as the representative of the Gaozhou complex and the Yunkai Group, respectively. The Gaozhou complex was formed during the Meso- to Neo-proterozoic and the Yunkai Group might have been formed in the Neoproterozoic. The Paleo- to Meso-Proterozoic crystallized basement does exist in Cathaysia Block, however，which is not so widely distributed as previously thought.
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2013,40(2):430-438, DOI:
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Abstract：Using samples from typical sections, drilling data and geochemical information from the Devonian black shale in Guizhong depression of central Guangxi, the authors analyzed the accumulation condition of shale gas reservoirs. The results demonstrate that there exist two suites of excellent marine source rocks in the middle and lower Devonian strata of Guizhong depression, which are characterized by large thickness and extensive distribution, high abundance of organic matter and moderate buried depth, thus possessing basic conditions for the formation of shale gas reservoirs. However, the preservative condition of shale gas is very poor because of the subsequent multistage severe tectonic movements as well as the development of faults and magmatic activities in some areas. Therefore, the central and western areas of Guizhong depression with integrated strata, underdeveloped faults and magmatic activities seem to be the favorable places for shale gas exploration. It is suggested that the preservation condition is very important in exploring shale gas resources under the conditions of high organic thermal evolution extent and subsequent multistage severe tectonic movements. The preservation condition is one of the key factors for shale gas exploration in China.
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ZHOU Jie1, 2, JIANG Yao-hui1, ZENG Yong2, GE Wei-ya2
2013,40(5):1379-1391, DOI:
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Abstract：Jingde pluton is one of the Mesozoic plutons in eastern Jiangnan orogen of northeast Yangzte Block. New LA-ICPMS zircon U-Pb dating for one granodiorite yielded an emplacement age of (141.0±1.0) Ma. The pluton is composed of monzogranite and granodiorite. New petrographical and petrochemical data show that the pluton is intermediate-somewhat acid (SiO2=66.01%~70.87%), and has high content of Al2O3 (Al2O3=14.91%~16.24%) and rich alkali (K2O+Na2O = 6.64%~8.01% ), with K2O/Na2O value ranging from 0.78 to 1.04. The pluton has relatively low content of MgO, TFe2O3 and P2O5 (MgO = 0.68%~1.06%, TFe2O3=2.0%~3.34%, P2O5 = 0.10%~0.14% ). As for trace elements, the pluton is enriched in Sr (189×10-6~452×10-6) with high Sr/Y ratios (23~66) and also enriched in light rare earth elements (LREE) ((La/Yb)N = 13 ~ 58) , but somewhat depleted in Nb, Ta, P, Ti, Y, Yb, with slightly negligible to positive Eu anomalies (δEu=0.81~1.18), similar to the geochemical characteristics of Mesozoic adakitoid in eastern China. Jingde pluton has relatively high Nd isotopes (εNd(t)=-6.28~-7.32), high εHf (t) values (-6.5~-1.1) and younger tDM2 model ages (1.4~1.5Ga), with mafic microgranular enclaves (MMEs), suggesting the importance of mantle material in the magma source. The mafic magmas ascended and heated the lower crust, triggering the partial melting of the lower crust to form the Jingde pluton, with the input of mantle-derived materials.
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LIN Jin1, 2, LI Yun1, 2, HE Jian1
2013,40(5):1542-1551, DOI:
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Abstract：By investigating data extracted from well cores, field outcrop samples, thin sections, cathodoluminescence images and the laboratory tests, the authors conducted a comprehensive study of the Carboniferous Benxi Formation in Yanchang area of Ordos Basin and then deduced its source directions from the angles of the mineral composition, genetic type, paleocurrent features, and enrichment regularities of rare earth elements. On such a basis, the authors analyzed the sedimentary facies distribution and evolution. It is revealed that from north to south in the study area, the sandstone grains decrease in size and increase in psephicity; the quartz cluster cathodoluminescence images are mainly fuscous, light-dark brown in color, indicating metamorphic genesis. The debris component is chiefly metamorphic debris, which is up to 85.1%. The paleocurrent of field outcrop moved northward, from northwest southward and southeastward. the distribution of the rare earth elements is quite similar to the Daqingshan old land at the northeast edge of the basin. It is thus concluded that the Benxi Formation primarily originated from Yinshan-Alxa in the north. The second stage of Benxi Formation in late Carboniferous epoch constituted a major turning point in the Upper Palaeozoic evolutionary history of Ordos. Due to the invasion of the slowly-subsiding sea water from the east, the study area formed a system composed of shallow argillaceous shelf, barrier island-lagoon and lagoon. The first stage was similar to the second stage in general features, but had larger argillaceous shelf and lagoon because of the intense water invasion, which had a good performance in the sand body continuity in parallel with the coastline.
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WANG Yong-lei1, CHEN Yu-chuan2, WANG Deng-hong1, XU Jue1, CHEN Zheng-hui1, LIANG Ting3
2013,40(5):1366-1378, DOI:
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Abstract：Antimony is one of the dominant minerals in China, which was listed as the first global shortage minerals by British Geological Survey in 2011. In this paper, based on the mineral resource potential assessment project, in combination with data available and grade III metallogenic belt research, the authors summarized the characteristics of antimony resources in China and preliminarily assigned antimony deposits in China to 13 large ore concentration areas, with a brief description of their geological characteristics. Meanwhile, based on the existing data and new advances in the exploration of antimony deposits in recent years, this paper makes a comment on the metallogenic characteristics of the six most important antimony ore concentration areas with an analysis of their resource potentials. The authors hold that there are still some blank areas for working as well as some potential prospecting areas around the known mines. The new prospecting direction is also pointed out.
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SHAN Liang1, 2, XU Rong-ke3, ZHENG You-ye1, 3, ZHANG Yu-lian4, CAO Liang5, PANG Ying-chun5
2013,40(5):1600-1611, DOI:
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Abstract：Beishan area is an important metallogenic belt, and the Baishantang Cu polymetallic deposit is one of the representative porphyry copper deposits. Two kinds of magmatic rocks along ore belt I in the Baishantang ore district were dated by the zircon LA-ICP-MS U-Pb method, which yielded a porphyry granite diagenetic age of （275.0±3.0）Ma (MSWD =1.17) , indicating early Permian. Two groups of ages were obtained for rhyolite porphyry: a magma zircon group of the rhyolite porphyry has an age of （371.1±2.8）Ma (MSWD=1.7) , suggesting late Devonian. The other inheritance zircon group of inheritance zircon with remarkable rounded shape or enveloped in the former group has ages of （2627±35）Ma, （2598±35）Ma, （705±44）Ma, （1722±48）Ma, （1642±51）Ma, （1213±54）Ma, which can be assigned roughly to 2.6 billion years, 1.7 billion years and 1.2 billion years, indicating that the rhyolite porphyry was related to the remelting of the upper-middle crust in late Devonian, as also shown by the geochemical characteristics.
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LI Bing1, 2, CHAO Dai-chao3, WEI Ming-jun2, 4, LI Yong-feng2, 5, LUO Zheng-zhuan2, 5, SHANG Jian-ge1
2013,40(5):1644-1654, DOI:
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The application of electromagnetic sounding method to deep iron ore exploration：A case study of the Wuyang iron mining area of Henan
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YAN Jian-she1, NIU Shu-yin2, FENG Jian-zhi3, SUN Wei-zhi3, SUN Ai-qun2, WANG Xing-cun3, CUI Xie-xiang3, CHEN Chao2
2013,40(2):538-548, DOI:
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Abstract：The Xiaoqinling gold ore concentration area is known for its great uplift amplitude, high denudation extent, intense tectonic movement, clear structural features and concentrated distribution of ore deposits. The study area experienced four periods of folding, comprising from early to late plastic flow folding→regional EW-trending main folding →NS-trending crossing superimposed folds→transverse folding of vertical uplift, and was subjected to four periods of shearing, in order of plastic flowing →brittle ductile transpression→ductile brittle tenso-shearing →brittle forward detachment caused by uplift. The main stage brittle-ductile shearing was developed in the main limb of the weak tectonic belt. The third phase ductile-brittle shearing process of Yanshanian period provided favorable ore-hosting conditions for the large-scale injection of ore-forming fluids and mineralization. Researches show that the ore-forming fluids were mainly derived from the depth and, through the multistage evolution of mantle plume, injected into the ductile shear zone to form ore deposits via accumulation. In the ore district, there often exist one or two main ore veins which control more than 50% of metallic reserves.
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NIU Xiao-lu1, YANG Jing-sui1, CHEN Song-yong1, LIU Fei1, XIONG Fa-hui1, LIU Zhao1, GUO Guo-lin2
2013,40(3):756-766, DOI:
Abstract:
Abstract：Located in the western part of the Yarlung Zangbo suture zone, the Dongbo ultramafic rock massif is comparable with the Luobusa ultramafic rock massif which holds the largest chromite deposit in China in terms of their petrology and mineralogy. In this paper, the authors attempted to characterize its origin by examining the geochemistry of platinum group elements (PGE), major elements and rare earth elements (REE) of the harzburgites which are the main rocks of the rock mass. The harzburgites are characterized by high abundances of Os (3.52×10-9~4.36×10-9), depleted major element compositions and low REE content (0.89×10-6~1.37×10-6) which is lower than that of the primary mantle, indicating that the Dongbo ultramafic rocks belonged to depleted residual mantle rocks after a significant degree of partial melting and melt extraction. They also have high PGE content (23.97×10-9~31.98×10-9) which is higher than that of primary mantle, and display IPGE-depleted, PPGE-enriched chondrite- and primary mantle- normalized PGE patterns with Pd/Ir being 1.49~2.65. Their chondrite- and primary mantle-normalized REE patterns are all U- or V-shaped with (La/Sm)m being 1.05~3.37 and (Gd/Yb)m 0.28~0.64 (primary mantle-normalized values). These features are consistent with the opinion that the Dongbo ultramafic rocks were formed by the interaction of depleted residual mantle rocks with melts/fluids which were enriched with incompatible elements and PGE, especially IPGE relative to PPGE. In addition, the low Cu/Pd ratios (1226~3448) argue that the melts/fluids should also have high content of sulfides. The authors infer that the melts/fluids that reacted with the residual mantle rocks probably originated from the magmas produced in a subduction-related tectonic setting.
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XU Tong1, PEI Xian-zhi1, 2, LI Rui-bao1, 2, LI Zuo-chen1, 2, PEI Lei3, LIU Cheng-jun1, CHEN You-xin1, WANG Xiao-wei1, YANG Jie1, HU Nan1
2013,40(6):1777-1792, DOI:
Abstract:
Abstract: Zhangyangou bimodal volcanic rocks are located in Hengxianhe area，Sanchazi-Lueyang segment of Mian-Lue tectonic zone. The bimodal volcanic rocks consist of metamorphosed basic volcanic rocks and metamorphosed acid-intermediate rocks in close association, and the protoliths are sub-alkaline basalt and sub-alkaline rhyolitic-dacite. On account of the higher REE concentrations in basalt than in rhyolitic-dacite, the authors hold that the origin of rhyolitic-dacite was partial melting of the crustal material rather than the fractional crystallization of the basaltic magma. Basic volcanic rocks show the intraplate geochemical characteristics such as high Zr concentrations and Zr/Y ratios, and their marks of arc result from the hybridism of the crustal material. The result of U-Pb isotope dating by means of Laser Ablation Inductively Coupled Plasma Mass Spectrometry makes it clear that the formation age of the rhyolite is (728±10) Ma(n=4, MSWD=0.14). Combined with the regional geological background, the authors consider that Zhangyangou bimodal volcanic rocks were formed in a continental rift environment under the crust extensional mechanism. The formation of Zhangyangou bimodal volcanic rocks heralded the opening of Neoproterozoic Ocean. This new achievement is of important significance both for the further study of the evolution of Mian-Lue tectonic zone and the breakup of Rodinia supercontinent and other continents on the north margin of the Yangtze block.
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DONG Lian-hui1, WANG Ke-zhuo2, ZHU Zhi-xin2, ZHAO Tong-yang2, XU Shi-qi2, ZHENG Jia-xing2
2013,40(5):1552-1568, DOI:
Abstract:
Abstract：Located in the convergence zone of India plate, Tarim-Sino-Korean paleoplate and Siberia ancient plate, Xinjiang has complicated geological structure. With an analysis of the characteristics of large deformation as a starting point, this paper comprehensively summed up such characteristics of the large-scale deformation structure as its type, size, pattern, material composition, structural order and deformation stage, discussed the control role of the large-scale deformation structure over stratigraphic framework, magmatic activities, metamorphism and deformation, regional tectonic evolution and metallogenesis, and divided the tectonics into 34 large deformation structures. The relationship between the evolution of large-scale deformation structure and the mineralization was tentatively investigated.
