Abstract:This paper is the result of oil and gas exploration engineering.
[Objective] The Chang 7 shale of Mesozoic Yanchang Formation in Ordos Basin is characterized by rapid changes of lithologies and lithofacies, thick, high abundance but low maturity of organic matter, high clay content and low-normal strata pressure. The study on shale gas enrichment conditions and development model of the Chang 7 shale is beneficial to explore the geological theory suitable for the exploration and development of Chang 7 shale gas, in order to provide guidance for the next exploration work in the region and further improve the geological theory of continental shale gas. [Methods] Based on drilling, core analysis, and test data, the accumulation and enrichment conditions of the Chang 7 shale gas were systematically studied from the aspects of hydrocarbon generation conditions, reservoir conditions and preservation conditions, and the enrichment and development model of shale gas was established. [Results] The results show that:(1) Chang 7 shale in the study area has high organic matter abundance, TOC is basically greater than 1.5%, and is in the oil and gas generation window, Ro is basically between 0.8% and 1.3%, and has the geological conditions of shale gas generation; (2) The clay mineral content is high, basically 40%-60%, which is beneficial to shale gas adsorption and has a certain adsorbed gas production; (3) The relatively stable tectonic background is an important condition for the preservation of shale gas; (4) The enrichment model of shale gas can be divided into two types:interbedded shale and sandy lamina type, and thick organic-rich shale type. The sandy lamina effectively improves the physical properties of shale reservoirs. The thick organic-rich shale deposited continuously is an important form of gas preservation. [Results] Based on the dissection of the enrichment characteristics of Chang 7 shale gas, the enrichment law of Chang 7 shale gas is summarized as "two large and one many":large gas generation potential, large continuous thickness and many sandy laminas.

Abstract:This paper is the result of oil and gas exploration engineering.
[Objective] The Yanchang Formation 8 in the northern Shaanxi region of the Ordos Basin has a wide oil distribution range and is an important target area for future exploration. However, the relationship between the evolution of hydrocarbons and the distribution of oil reservoirs is still unclear. [Methods] Based on the analysis of the occurrence characteristics, composition and homogeneity of fluid inclusions, geological and geochemical methods are used, the oil source and reservoir forming characteristics of Chang 8 tight sandstone are discussed, and the formation time of Chang 8 reservoir and its relationship with hydrocarbon accumulation are revealed. [Results] The fluid inclusions in Chang 8 sandstone reservoir are mainly gas-liquid hydrocarbon inclusions and gasliquid two-phase brine inclusions, which are distributed in quartz enlarged edge or fractures of fine sandstone, and can be divided into early and late stages. The homogenization temperature of brine inclusions associated with gas-liquid hydrocarbon inclusions mainly has two peak ranges of 85-105℃ and 115-135℃, which shows that oil and gas are continuously filled. The history and evolution of reservoir formation shows that the main filling period of Chang 8 oil is 110-135 Ma, during which the early filling in late Jurassic and large-scale filling in early Cretaceous occurred. The source rocks of Chang 7 in the region are mainly developed, and the Ro value is close to 1.0% in the maximum hydrocarbon generation and expulsion stage, reaching the hydrocarbon generation threshold and generating a large number of hydrocarbons. The source rocks of Chang 9 are locally distributed in Zhidan area. [Conclusions] Combining the characteristics of inclusions with the formation of hydrocarbons, the Chang 8 reservoir in Northern Shaanxi is controlled by factors such as source rock, reservoir and hydrocarbon charging. The oil filling degree is different, and the lithologic reservoir is developed differently, which shows two sets of source rocks hydrocarbon supply and differential accumulation.

Abstract:This paper is the result of oil and gas exploration engineering.
[Objective] There is a good prospect of oil and gas exploration of Juyanhai depression of Yingen-Ejin Basin, but there are some controversies on the understanding of the age of the main petrostratigraphic unit and the age of the main oil-bearing reservoir revealed by wells, so it is great significance to the evaluation and study of oil and gas geological conditions, and the exploration and deployment by systematic stratigraphic division and correlation, and define the ages of the main petrostratigraphic units and oil and gas layers for the tectonic and sedimentary evolution of the basin. [Methods] Based on the comprehensive study on the petrology, lithologic association and paleontological characteristics of wells in different sags,, the formation correlation mark established by regional formation characteristics, unconformity interface determined by seismic profile, constraints on stratigraphic age of LAICP-MS zircon U-Pb and so on, the conclusion of stratigraphic division and correlation is formed. [Results] There are two structural layers of Cretaceous and Carboniferous and Permian of wells in Juyanhai depression, the correlation marks of strata in each depression are significant, and the main oil-bearing strata are the middle-Lower Permian and Ganquan formation of Upper Carboniferous and Lower Permian. [Conclusions] Yingen-Ejin Basin is a superimposed basin of Carboniferous-Permian and Cretaceous, and the geological conditions of Carboniferous and Permian are favorable, so it should be used as the direction of oil and gas exploration.

Abstract:This paper is the result of mineral exploration engineering.
[Objective] Typical sandstone type uranium deposits are developed in Huatugou area, Northwest Qaidam Basin. The uranium reservoirs are Qigequan Formation, Shizigou Formation and Youshashan Formation, while Shizigou Formation is somewhere in between Qigequan Formation and Youshashan Formation. It is an urgent geological problem to correctly understand the relationship between sedimentary characteristics of Shizigou Formation and sandstone-type uranium deposits. [Methods] In this paper, the sedimentary characteristics of Shizigou Formation are studied based on the sandstone-type uranium deposit prospecting work in the Qaidam Basin, and we analyzed the stratigraphic sequence frame, cause mechanism, provenance characteristics and their relationship with uranium ore from Shizigou Formation. [Results] The colour of greywacke collected from ZK10 in Yuejin 2 area is brownish red, while the main body is calcareous argillaceous sandstone, which belongs to carbonate terrigenous clastic greywacke. Specific value of CIA=37.79-69.14, ICV=0.84-2.13, Σ=1.39-2.14, K₂O/Na₂O=0.90-1.18 (the average is 1.06), which indicated that there are relatively much more potassium feldspar or potassium minerals in the greywacke. The measuring result from a depth of 224 to 240 meter is GR=0-30 API, RT=-5-45 Ω·m. The logging facies is box type, and the amplitude of the curve is large. The measuring result of greywacke is K₂O/Al₂O₃=0.22-0.27, Ni/Co=0.34-0.53. [Conclusions] The sediment environment of Shizigou Formation in Yuejin 2 area belongs to fluvial facies. The source rocks of the upper Shizigou Formation contain less clay material, and were deposited for the first time under the dry and cold paleoclimate environment. The source rock of greywacke in the Shizigou Formation were formed in the continental island arc environment, which the sedimentary source rock of the greywacke is the alkali feldspar with a small amount of felsic rocks. The sedimentary environment of the formation is very conducive for the formation of uranium deposits.

Abstract:This paper is the result of oil and gas exploration engineering.
[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, and 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, which 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.

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.

Abstract:This paper is the result of geothermal geological survey engineering.
[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 1177 MW in 2005 to 4000 MW 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 Türkiye's government has vigorously supported the development of geothermal energy industry since the 21st century. 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] Drawing on the rapid development experience of Türkiye's geothermal energy industry and combining with China's actural conditions, the following suggestions are put forward:(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.

Abstract:This paper is the result of geothermal resources survey engineering.
[Objective] In Guangxi, the geothermal resource is extensively distributed, and is a competitive low-carbon, renewable and clean energy. Up to now, the systematic research on the occurrence regulation, distribution characteristics and potential of geothermal resources is relatively weak, to a certain extent, which restricts the comprehensive development and utilization in Guangxi.[Methods] In this paper, we systematically analyzed the structure of the crust and mantle layer, the present characteristics of the geothermal field and the distribution pattern of geothermal resources, based on the latest results of the survey and evaluation of shallow geothermal, hydrothermal and hot dry rock geothermal resources in Guangxi since the "Twelfth Five-Year Plan". And we chose different methods to evaluate the development and utilization potential of shallow geothermal energy resources, hydrothermal geothermal resources and hot dry rock geothermal resources. [Results] The research shows that the geothermal resources are rich in Guangxi, with obvious occurrence rules and zoning characteristics. In 13 major cities, the shallow and hydrothermal geothermal resources are mainly developed through direct utilization, and the shallow geothermal resources are 1.23×10¹⁵ kJ/℃, the annual exploitable resources are 1.36×10¹² kJ/a, equivalent to 1.67×10⁸ t standard coal. And 24 warm(hot) springs points and 28 geothermal mining wells locating in Guangxi, the total amount of geothermal energy resources is 2.56×10¹⁷ kJ, which is equivalent to 87.58×10⁸ t of standard coal. On the other hand, the annual recoverable heat of geothermal fluid is 28.89×10¹² kJ/a, which is equivalent to 315.65×10⁴ t of standard coal. Finally, the potential of dry hot geothermal resources is great in Guangxi, within 3-10 km of the land area, the total amount of hot dry rock resources is 55.42×10⁴ EJ, which is equivalent to 18.91×10¹² t of standard coal, at a recoverable rate of 2% which is 75.94 times the 2020 Chinese primary energy consumption(4.98 billion tons). Therefore, it is becoming the most ideal replacement carrier for traditional fossil energy.[Conclusions] Guangxi is lack of coal, oil and gas in the traditional energy field, and has rich wind, water and heat in the new energy field. The rational development and utilization of geothermal resources will contribute to the optimization of energy structure and the strategic adjustment of industrial structure in Guangxi, and help to achieve the "dual carbon goal".

Abstract:This paper is the result of mineral exploration engineering.
[Objective] Natural soda-ash deposits, also called sodium carbonate evaporites, are mainly used to produce soda ash. In the soda industry, compared with synthetic soda, this process has advantages for environmental protection and lower cost. The downstream industries contain various fields, including glass, medicine, and so on. The booming of new energy industries such as photovoltaic has brought new demand for soda ash. China consumes loads of soda ash annually; thus, soda may become a scarce resource in the future. Mineralization process of natural soda-ash evaporites is of great significance in evaporite community. In China however, soda-ash deposits have received little attention and have great research potential. Investigations on types and distribution characteristics of global soda-ash deposits and their genesis are helpful and useful for deepening research and prospecting of Nacarbonate deposits in China. [Methods] Compiling published data and systematically summarizing the regional setting, provenance, genesis of typical soda-ash deposits. [Results] Most deposits are Cenozoic in age and located in North America, Asia and Africa. Modern soda-ash deposits predominate in number, but resources size of ancient deposits is tremendous. Specific ancient deposits include the Green River Formation, United States and the Anpeng soda deposit in Biyang Depression in Henan, the counterparts, typical modern alkaline lake deposits formed in Lake Magadi, Kenya and Chaganor, Inner Mongolia. [Conclusions] The requirement for Na-carbonate deposits precipitation are (1) hydrologically-closed basins, (2) arid climate, and (3) sufficient sodium carbonate supply. Unlike other evaporites, the sources of CO₂ required to maintain Na-carbonate brines are complicated. Efforts for prospecting in China should focus on Quaternary saline lakes, Cretaceous restrict basins in Inner Mongolia, and tectonically-closed depression in which dolomite and oil shale develops in Henan. It is of great significance to carry out the metallogenic theory research and mine prospecting.

Abstract:This paper is the result of mineral exploration engineering.
[Objective] Boron is an important non-metallic key mineral resource and an important industrial raw material in the new technology industry. China is not only a major producer of boron deposits, but also a major importer. Eighty-two percent of boron ore comes from abroad. Studying the origin, distribution and prospects of boron mineral deposits is an effective way to address the massive dependence on imports of boron resources, which is beneficial to the development of the national economy. [Methods] By collecting public information, this paper summarizes the genesis types, distribution and application of boron deposits. [Results] Boron deposits can be divided into volcanic sedimentary type, sedimentary metamorphic type, skarn type, modern salt lake type, underground brine type and marine evaporative sedimentary type. It is mainly distributed in the Pacific Rim and the Mediterranean coast, such as Kestelek, Emat, Bigadic and other deposits in Turkey, Kramer deposit in the United States and Uyuni Salt Lake in Bolivia, accounting for about 90% of the global reserves. [Conclusions] Among them, volcanic sedimentary boron deposits account for about 75% of the global total, and the lowest grade is 25% (B₂O₃), which is an important deposit type in the world. Modern salt lake type boron deposits account for about 20%, grade 8%-30% (B₂O₃). The sedimentary metamorphic boron deposit is an important boron industrial deposit in China, with ore grade of 11% (B₂O₃). The world is divided into six regions of metallogenic potential based on the size and distribution of boron deposits.

Abstract:This paper is the result of hydrogeological survey engineering.
[Objective] Shaanxi Province is an important province where 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 Shaanxi Province of the Yellow River Basin is 77.59×10⁸ m³/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 and 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, whereas Tongchuan City has the lowest development and utilization degree. [Conclusions] The distribution of groundwater resources and development potential in Shaanxi Province of the Yellow River Basin 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.

Abstract:This paper is the result of environmental geological survey engineering.
[Objective] Organic pollutants, such as chlorinated hydrocarbons and BTEX, have an important threat to groundwater environment in China. Natural attenuation monitoring plays an important role in contaminated sites remediation. Researches on natural attenuation monitoring will be conductive to promoting the development of groundwater organic pollution control and environmental remediation technologies. [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 attenuation kinetic equation. [Results] The results show that the natural attenuation of TCP and benzene occurred in the aquifer for different degrees, and ORP values of the groundwater in phreatic and confined aquifer were -225~-57 mV and -182~-3 mV, respectively, which were medium-high reducing environment with basic environmental conditions for anaerobic biodegradation of organic pollutants. Moreover, the effect of microbial degradation was stronger in the pollution source area and phreatic aquifer 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] According to the different degree of groundwater pollution, the natural attenuation monitoring technology can be used alone or combined with other remediation methods and technologies, which is a low cost and high efficiency method to reduce groundwater organic pollution for this kind of industrial contaminated sites.

Abstract:This paper is the result of monitoring and evaluating engineering of natural resources.
[Objective] As a new expansion business of China Geological Survey in 2021, the comprehensive survey of natural resources aims to serve land and space planning, use control and ecological protection and restoration. [Methods] Based on the monitoring data of land use/cover change in the watershed in 2000, 2010, and 2020, ArcGIS software was used to analyze the spatiotemporal changes in land use types and ecological space of Weihe River Basin. [Results] The results show that:1) during 2000-2010, 804.4 km², 350.3 km² and 327.6 km² of cropland converted into grassland, forest and constructive land respectively, while only 94.3 km² grassland, 10.4 km² forest and 1.2 km² constructive land converted into cropland; 2) during 2010-2020, 16646.8 km², 3024.5 km² and 2547.9 km² of cropland converted into grassland, forest and constructive land respectively, while 16867.7 km² grassland, 3103.6 km² forest and 2528.82 km² constructive land converted into cropland; 3) during 2000-2020, the conversion of ecological space land in this region reaches 48,165 km², of which the ecological→semi-ecological land was 20172 km², the semi-ecological→ecological land was 20,897 km², the weak ecological→semi-ecological land was 2,519 km², and the semi-ecological→weak ecological land was 2754 km². It reflects that the conversion of ecological space land in the region tends to balance and the quality of the ecosystem is slowly increasing. [Conclusions] The results is of great significance for accelerating comprehensive regionalization of natural resources and optimizes "three-zone and the-lines" of the Territorial Spatial Plan in the Weihe River Basin.

Abstract:This paper is the result of hydrogeological survey engineering.
[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 SO₄^2-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 SO₄^2-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, SO₄^2-, 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.

Abstract:This paper is the result of geological survey engineering.
[Objective] As the main terrane in the Tibetan Plateau, the division of the Lhasa terrane is significance for the spatial and temporal distribution pattern of the Tethys Ocean. Generally, it can be further divided into the North, Central, and South Lhasa terranes. However, it is still ambiguous about their basement nature, drifting, accretion, and tectonic affinity. [Methods] In this paper, based on the 1:50000 geological survey in the Beila area, North Lhasa terrane, the widely exposed and typical tillite and seismite are newly identified from the Middle-Upper Jurassic Lagongtang Formation, northern Tibetan Plateau. [Results] They can be compared with the Upper Carboniferous-Lower Permian Lagar Formation in the Xainza area, Central Lhasa terrane, indicating the Late Paleozoic glacial event in the northern margin of the Gondwana. The glacial marine gravels, formed by ice raft, are distributed in the sandy, silty and argillaceous matrix, with falling structure. Seismites are mainly seismic corrugated and shattering, with syngenetic or parasyngenetic seismic sedimentary records of microfolds, sand (mud) veins, coseismic joints, intraclastpara-breccia, steplike faults and flame structures. [Conclusions] The identification of the tillite of Lagar Formation indicates that the North Lhasa terrane holds similar basement with the Central Lhasa terrane. It is probably anaccretion-induced micro-block formed gradually on the basis of local continental crust, which is closely related to the subduction process of the Bangong-Nujiang Tethys Ocean. This provides key evidence for further studying the tectonic affinity of the North Lhasa terrane.

Abstract:This paper is the result of mineral exploration engineering.
[Objective] Minerals formed by magmatic differentiation, such as feldspar and biotite, can be used as indicators of magmatic evolution of host rocks.There are disputes between rhyodacite and rhyodacite porphyry from Xiangshan, in the aspects of formation age, origin, material source and mantle material participation. [Methods] In this paper, the electron probe technology is used to quantitatively analyze the feldspar and biotite in two types of rhyodacites in Xiangshan, and the composition, material source, formation temperature, oxygen fugacity and rock properties of the two types of rhyodacites are analyzed and studied. [Results] The results show that the rhyodacite of Xiangshan Daguding Formation can be divided into two types, one is the effusive rhyodacite (K₁d^2a) and the other is the intrusive rhyodacite porphyry (K₁d^2b). The types of feldspar from rhyodacite are more than those of rhyodacite porphyry. The feldspar types of rhyodacite include albite, potassium feldspar, potassium sanidine, feldspar and andesine. The main feldspar types of rhyodacite porphyry are albite, potassium feldspar and potassium-sanidine. The biotite formation temperature of rhyodacite and rhyodacite porphyry is basically the same (750±20℃). Rhyodacite and rhyodacite porphyry both have high oxygen fugacity and belong to calc-alkaline rocks, indicating the same magma material source with part from mantle material. [Conclusions] The chemical composition is basically the same, together with the same feldspar type, the same material source, the same crystallization temperature, the sameoxygen fugacity, and the same rock properties, indicating that the two have homology.

Abstract:This paper is the result of mineral exploration engineering.
[Objective] The Ashawayi gold deposit, located at the central and southern margin of the "Asian Gold Belt", is a newly discovered medium-sized gold deposit in southwestern Tianshan Orogen, NW China. [Methods] Through field geological survey, indoor research on fluid inclusion petrology, fluid inclusion composition analysis, fluid inclusion temperature measurement, H-O isotope and so on is carried out. [Results] The deposits are hosted in Kalazierjiao Group, Late Carboniferous, and ore bodies are produced in secondary faults of the NEE-trending thrust nappe system. According to the relationship between vein cutting and mineral metastasis, the mineralization process can be divided into three stages. Microscopic observation analyses of inclusions in quartz showed that there were three compositional types of fluid inclusions, i.e. pure CO₂, CO₂-H₂O and NaCl-H₂O in the early and middle stage, but only pure H₂O inclusions in the latest. Measurement of inclusions trapped in quartz revealed that the total homogenization temperatures were 236-386℃ in the early stage, 225-301℃ in middle and 139-222℃ in last, respectively, with corresponding salinities of 1.6%-9.7%,1.4%-12.5%, and 1.4%-7.3% NaCl eqv.. The laser Raman spectrum of fluid inclusions showed that the liquid was composed of H₂O and CO₂, a few of CH₄ and N₂, indicating that the ore-forming fluid was a kind of medium-low temperature, rich of CO₂, bearing few of CH₄ and N₂, and low-salinity metamorphic fluids. The estimated pressures based on CO₂-H₂O type inclusions are 140-180 MPa in the early stage and 130-160 MPa in the middle, corresponding a depth of 5-7 km and 5-6 km, respectively, under the static rock pressure. The content of H-O isotopes of quartz showed ore-forming fluids changing from a kind of deep-source metamorphic fluid in the early stage, to a metaphase and atmospheric precipitation mixed fluid in the middle, and to a hydrothermal fluid of late-seasonal precipitation in the last. [Conclusions] Comprehensive analysis suggested that the fluid system stress reduction, immiscible or boiling, the escape of CO₂-CH₄ and other gases, and the development of vulcanization and carbonate, should result to the rapid precipitation of the gold and the deposit is a typical medium-shallow orogenic-type gold deposit.

Abstract:This paper is the result of geological survey engineering.
[Objective] The Baiyingaolao Formation is an important part of the Mesozoic volcanic rocks in Great Xing'an Range, Northeastern China, and the geochronology and geochemistry characteristics of the Baiyingaolao Formation can provide basic geological data for the tectonic evolution of Great Xing'an Range. [Methods] In this paper, LA-ICP-MS zircon U-Pb age and geochemistry of the rhyolites in Baiyingaolao Formation from Wunuer area in Great Xing'an Range have been carried out. [Results] The testing results indicate that the LA-ICP-MS zircon U-Pb crystallization age is (127.6 ±1.2Ma) Ma, which belongs to Early Cretaceous. The rhyolites belong to high-SiO₂, high-K peraluminous, calcalkaline series. The rhyolites are enriched in Rb, Ba, K, depleted in Sr and Nb, P, Ti, and LREE is enriched and HREE is relatively depleted, with moderate Eu-rich anomaly (δEu=0.49~0.87). [Conclusions] Combined with regional geological characteristics, the tectonic setting of rhyolites in Baiyingaolao Formation from Wunuer area in Great Xing'an Range may be related to the subduction of Pacific plate.

Abstract:This paper is the result of mineral exploration engineering.
[Objective] The Jinshajiang-Honghe alkaline-rich porphyry Cu-Au polymetallic metallogenic belt, which produces numbers of large-scale Cu-Au deposits including the Yulong at the north, the Beiya in the middle and the Tongchang at the south, for example, has becoming one of the most productive ore clusters and research focus in the east Tethys domain. [Methods] Based on long-term integrated field investigations and published data analysis, we summarized the characteristics of the typical deposits and the alkaline-rich porphyry. [Results] The alkaline-rich porphyry mainly consists of monzonitic granite porphyry and quartz syenite porphyry, showing high contents of K₂O-Na₂O, Al₂O₃, LREE and deficit in HREE and HFSE. Similar Sr-Nd isotopic composition indicates that the source area is mainly lower crust material. The development characteristics of regional strike-slip structures and their constraints on diagenesis and mineralization in this area are also discussed, and a "regional structure→alkaline-rich magma→Cu-Au polymetallic" mineralization process controlled by the deep Jinshajiang-Honghe strike-slip fault and its secondary structure activities in the east Tethys metallogenic domain is further summarized. [Conclusions] Through field observation and study on the main faults in the three typical areas, we suggest that the alkaline-rich magma and related Cu-Au mineralization were primarily controlled by the secondary northwestward faults of the regional Jinshajiang-Honghe strike-slip fault.

Abstract:This paper is the result of geological survey engineering.
[Objective] The Kaladawan area is located within the area defined by the NE-striking Altun strike-slip fault to the north and EWstriking northern Altun fault. The cumulated gabbro is exposed to the north Altun Fault 4 km to the south, basic marine volcanic rocks such as occipital basalt occur in both north and south. As the main component rock type of oceanic crust, the study of cumulate gabbro will further reveal the evolution characteristics of early Paleozoic Altun oceanic crust. [Methods] In this paper, petrology, mineralogy, geochemistry and zircon SHRIMP U-Pb dating of cumulate gabbro in the Kaladawan area have been studied. [Results] The study shows that the cumulate gabbro in Kaladawan can be divided into two types:pegmatite and coarse-grained, and has the characteristics of gradual transition. The geochemistry features include low K₂O content (average is 0.44%), flat REE partition curves (the average LREE/HREE value is 2.54), positive Eu anomalies (the average δEu value is 1.05), and negative Nb and Ta anomalies (the average Nb and Ta content is 2.31×10^-6 and 0.16×10^-6, respectively), which indicates that it occurs in the tectonic environment of the back-arc basin. The zircon SHRIMP U-Pb age of 514-516 Ma is very close to that of the adjacent intermediate-basic volcanic rocks of 517 Ma, indicating that the cumulate gabbro was formed in late Cambrian of the early Paleozoic. [Conclusions] The results show that there was an obvious oceanic crust spreading during the late Cambrian in the Kaladawan area. This result, together with island arc intermediate-acid volcanic rocks 478-485 Ma and co-collisional intermediate-acid intrusive rocks 477-488 Ma, constitutes a complete sequence of regional tectonic evolution, and an evolutionary history of the early Paleozoic oceanic crust spreading and plate subduction to continental collision in the North Altun region is further determined.

Abstract:This paper is the result of geological survey engineering.
[Objective] The petrogenesis and magmatic origin of the early Cretaceous diorite in Jinjingzui gold deposit are of great significance for the diagenetic and metallogenic relations and perfecting the regional metallogenic regularity. [Methods] In this study we report the Sr-Nd and zircon Hf isotopic compositions of diorite in Jinjingzui deposit. [Results] The results show that the diorite has relative high initial ⁸⁷Sr/⁸⁶Sr ratio (0.7059-0.7062), negative ε_Nd(t) values (-7.93--7.58) and ε_Hf(t) values (-12.2--6.5), suggesting the magma was derived from partial melting of an enrichment mantle, followed by magma differentiation. There may be continental crust contamination during magmatic evolution. [Conclusions] By comparison with reported deposit in cluster, Jinjingzui Au deposit is similar to these Au deposit at Edong cluster in rock- and ore-forming ages, petrogenesis and magma source. However, the gold orebody of Jinjingzui Au deposit mainly lay within the diorite body, which is obviously different from other deposits that lay internal or external contact zone of rocks. The discovery of Jinjingzui deposit is of great significance for perfecting regional metallogenic regularity and gold prospecting and exploration.

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