Abstract:This paper is the result of mineral exploration engineering. Objective Jiaodong Peninsula is a famous gold metallogenic area in the world. The gold deposits are mainly controlled by fracture. Certainly, there are still many fractures in this area without ore. In the past, the deep form of the fracture and the distinction between the ore-bearing faults and the ore-free faults have not been thoroughly studied. Methods In this paper, the gravity, magnetic and electric length profiles, wide area electromagnetic profiles and reflection seismic profiles that traverse the main gold deposits areas in Jiaoxibei area are used to reveal the deep characteristics of the fractures, providing important evidence for the identification of ore-bearing faults and ore free faults. Results The geophysical detection shows that there are deep faults with steep dip angle, shovel faults with gentle dip angle and small faults with steep dip angle in Jiaoxibei area, among which the ore-controlling Sanshandao, Jiaojia and Zhaoping faults are shovel faults. Combined with the study on the gold deposits, it is found that the deposits mainly occur in the gentle dip faults, the ore bodies present the step-like mineralization pattern, while no obvious gold mineralization alteration has been found in the deep faults, and the maximum depth of the present gold deposits are about 5 km. Conclusions Comprehensive analysis shows that the low-angle detachment faults and the large-angle small faults have better physical trap conditions, which are conducive to mineralization enrichment. However, the deep faults with flat and steep dip do not have the condition of physical trap, which are not conducive to mineralization. The prospecting direction of Jiaodong type gold deposits should be concentrated in the vicinity of the gentle dip shovel faults and its derived and associated small steep dip faults.

Abstract:This paper is the result of mineral pexploration engineering. Objective Granite pegmatite type lithium deposit is the main supplying type of metal lithium in the world today. The development and policy formulation are restricted seriously by the shortage of economic and available granite pegmatite type lithium mine in China. In order to clarify the commonality of granite pegmatite-type lithium deposits, we make a prospecting prediction plan, and delineate high-quality prospecting targets. Methods This paper systematically compares the spatial-temporal distribution, tectonic background, ore deposit geology, ore body characteristics, mineralization regularities and ore controlling factors of granite pegmatite type lithium depsoits in China, and summarizes the characteristics of lithium-producing granite. Results It is believed that the granite pegmatite-type (spodumene) lithium ores discovered in China are mainly distributed in the west part, and the granite-type (lepidolite) lithium ore is dominant in the east part. The post-collision environments since the Paleozoic are the main output background of the existing pegmatite-type lithium deposits in China, and the mineralization setting can be extended to the non-orogenic tectonic environment, and most of the metallogenic element combinations have the characteristics of LCT-type pegmatites, and the number of deposits and resources are the largest in the late Indosinian. Lithium-producing granite is generally a multi-stage compound rock mass in the same period, and its evolution differentiation is high. The granite is lighter in color, rich in K, Na, P, F, Rb, U, Th, high oxygen fugacity, high Rb/Sr, low Nb/Ta and Zr/Hf, which is the most closely related to granite pegmatite type lithium deposit, and it is easier to identify than granite pegmatite dikes. Conclusions Under the guidance of the concept of "whole mineralization, absent prospecting", starting from the search for lithium-producing granite with a larger target, "first prospecting, then optimizing, and mapping in the last", it is expected to achieve a prospecting breakthrough in the "boundary mountain" granite where the secondary structural unit is converted from extrusion to stretching, especially in the outer contact zone of wavied and tongue-like intrusive boundaries.

Abstract:This paper is the result of mineral exploration engineering. Objective As the world's scarce strategic mineral resource, high-purity quartz is the key basic material of strategic emerging industries. Spruce-Pine granitic pegmatite was used as raw material by the United States to produce high-end quartz sand products, which were better than the quality of 4N8, and almost monopolized the international market. The discovery of 4N class high-purity pegmatite-quartz deposits in Eastern Qinling provides a rare opportunity to study the formation mechanism of high purity quartz, realize prospecting breakthrough and establish metallogenic model. Methods Based on the field investigation of the newly discovered high-purity pegmatite-quartz deposits in the Eastern Qinling Mountains, the geochemistry, zircon U-Pb isotope chronology and Hf isotope of pegmatite deposits in Spruce-Pine high-purity quartz deposits in the United States were compared. Results The Eastern Qinling 10 high purity quartz deposit was formed in the Early Devonian with a zircon U-Pb age of (406.8±0.8) Ma, which is earlier than that of high purity quartz granite-pegmatite in Spruce-Pine. The formation temperature of pegmatite from high purity quartz deposit in Eastern Qinling and Spruce-Pine is about 600℃. Pegmatite from the high purity quartz deposit in the Eastern Qinling has similar geochemical characteristics to pegmatite from the high purity quartz deposit in Spruce-Pine, showing features of I-type granite and high differentiation evolution. The materials in the source area come from both lower crust and mantle. It is not enough to completely invert the characteristics of the source area and the diagenesis and mineralization process by compared the spatial relationship with formation age and petrogeochemical characteristics. Whether the pegmatite of high purity quartz deposits and Huichizi granite pluton in the Eastern Qinling have the homologous evolution still needs further study. Conclusions Compared with the granite type, magmatic characteristics and formation temperature of the high-purity quartz deposits (points) in the Eastern Qinling and Spruce-Pine are similar, which provides a theoretical basis for further revealing the geological background of high-purity quartz mineralization and achieving breakthroughs in high-purity quartz ore deposits prospecting.

Abstract:This paper is the result of oil and gas exploration engineering. Objective It is necessary 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.

Abstract:This paper is the result of oil-gas exploration engineering. Objective The Triassic Yanchang Formation in the Gufengzhuang area of the western Ordos Basin develops low-permeability reservoir with abundant natural fractures, and few investigations have focused on the features of the fractures that are of great significance for the exploration and development of low-permeability reservoirs. Methods In this paper, by means of fracture identification from the outcrops, cores, imaging logging, scanning electron microscope and fluid inclusion, fault activity and tectonic stress analysis, the fracture characteristics and influence on low permeability reservoirs are studied. Results The results show that natural fractures are all developed in each Member of the Yanchang Formation, with Chang 7 being the most developed Member, followed by Chang 8 and Chang 6 Members. The fracture mainly orients in the NEE direction, secondly in the NE direction, and lastly in the NW and NWW directions. Calcite filling and obvious oil migration marks can be seen on the surfaces of the cracks. The development degree of natural fractures is closely related to the thickness of rock layers and intensity of fault activity. Comprehensive analysis of the fluid inclusions in fractures, faults and tectonic activities shows that the formation period of fractures is multi-stage, mainly in the 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 oil migration, accumulation and enrichment in low-permeability reservoirs. The development degree and formation period of natural fractures affect the reservoir forming and productivity of low-permeability reservoirs.

Abstract:This paper is the result of oil and gas exploration survey engineering. Objective Xiaoquan-Fenggu area in the western Sichuan Basin has huge potential for exploration and development of Xujiahe Formation gas reservoirs. However, due to the region's deep burial, complex structure, and multiple superimposed fault systems that cause frequent variation in stress orientation, effective well placement design and hydraulic fracturing practices have been limited. Therefore, it is necessary to evaluate the precise magnitude of in-situ stress in this area to provide recommendations for engineering development and increase production capacity. Methods Experimental methods such as rock mechanics, acoustic emission testing, and differential strain analysis combined with conventional logging, special logging, and hydraulic fracturing data were used to experimentally test the in-situ stress magnitude in deep heterogeneous blocky tight sandstone reservoirs. Based on accurate evaluation of single-point in-situ stress magnitude, a logging interpretation model was established for the subdivision of tectonic units in the study area, examining structural variation of in-situ stress magnitude and distribution along a single well. Results Our study showed that differential strain analysis provided the most accurate measurement of stress in heterogeneous tight sandstone reservoirs. Test results indicated that the Xujiahe Formation belongs to the type III in-situ stress category and exists in a strike-slip stress state with partial compression and thrust stress states. Based on single-point test data, we developed a technique to evaluate in-situ stress magnitude by utilizing borehole image inversion. Structural changes in in-situ stress magnitude were divided vertically into five types, whereby high positions of north-south (SN) faults with grades above three and folds in SN or northeast-trending (NEE) resulted predominantly in low-low-high (LLH) or low stress (LC) profiles. Meanwhile, small-scale faults or gentle deformation areas had high-low-high (HLH) or high-low-low (HLL) profiles. Conclusion A low-low-high (LLH) stress profile was suggested for engineering development to penetrate more gas layers vertically, while avoiding bottom water and preventing rapid water breakthrough during early production. Therefore, it is recommended to select the second to third order north-south(SN) trending faults and north-south(SN) or northeast trending(NE) longitudinal flexure zones located in the middle-upper part of the second layer of the second member of Xujiahe Formation.

Abstract:This paper is the result of geological survey engineering. Objective In the modern energy system, energy reserve plays an important role. Strengthening the energy reserve system, ensuring stable energy supply, and handling the impact of various emergencies in the international and domestic energy markets are an important topic in China's energy development. Methods Based on the types of underground space storage facilities, combined with the construction of global underground space storage facilities and related research experiments, this paper deeply compares and analyzes the development status of oil and gas storage in the world and China, so as to put forward reasonable suggestions to ensure energy security. Results (1) The utilization of underground space for energy storage is an important direction of future energy storage maintenance. This is an effective way to peak regulation of natural gas, sustainable supply of renewable energy and efficient use of hydrogen on a large scale. The development of underground space energy storage is a key issue to achieve carbon neutrality and upgrade China's energy structure; (2) Global underground space energy storage facilities can be divided into five categories: salt cavern, water-sealed cavern, aquifer, depleted oil and gas reservoir and abandoned mine; (3) The construction of underground space energy storage facilities was carried out earlier in foreign countries, which should take the lead in the construction of underground energy storage power stations, underground hydrogen storage facilities, oil reserves and natural gas reserves. Conclusions In the complex international background, China's energy security faces severe challenges. It is imperative to investigate the energy storage capacity of underground space, establish more underground space storage facilities and carry out national underground storage planning together with related enterprises.

Abstract:This paper is the result of environmental geological survey engineering. Objective Heavy metals such as cadmium, chromium, lead, copper and zinc are typical harmful elements in soil. Excessive intake can inhibit the growth and development of the organism. Its distribution in soil is influenced by the origin of primary geological background and human activities such as mining, atmospheric subsidence, pesticide and fertilizer application. However, the distribution characteristics of soil heavy metals under different land use types need to be further identified. Besides, the harmful effects of typical heavy metals need to be comprehensively sorted out and revealed. Methods By referring to the relevant research content at home and abroad, the spatial distribution characteristics of typical heavy metals in soil were sorted out, the effects of heavy metals on organisms in soil were summarized, and the toxic effects and targeted remediation methods of human exposure to high heavy metals in soil and groundwater were summarized. Results The results showed that the heavy metal content in soil had significant spatial variability due to the combined effects of primary geological background and land use type under human activities. The different content of heavy metals in soil will have different effects on the growth and development of soil microorganisms and plants, and enter the human body through the food chain and accumulate. When the accumulation of heavy metals in the human body is too high, it will destroy different organs and systems of the human body and threaten human health. Conclusions Pollution mode, pollution level and exposure route should be taken into account in the targeted treatment of heavy metals.

Abstract:This paper is the result of hydrogeological survey engineering. Objective The development of coal resources in the Yellow River Basin has led to serious groundwater pollution. This paper summarizes the situation from the overall perspective of the basin, providing prevention and control suggestions for its sustainable and healthy development and reasonable protection of groundwater resources. Methods Starting from the strategic position of the Yellow River basin, the causes and patterns of pollution are summarized. The improved comprehensive water quality index method was used to evaluate the groundwater quality of nine major coal bases in the basin. The weighted indicators were selected using principal component analysis, and the improved Nemero pollution index method was introduced. The evaluation was conducted according to the WPI classification method. Results The research shows that through the water quality evaluation of various key sections of the Yellow River basin, it is found that the water quality results of coal bases in the basin currently account for more Class III and Class IV, with poor water quality. Currently, the pollution of highly mineralized mine water, acidic mine water, and mine water containing special components in the drainage basin is relatively large. The causes of pollution are analyzed, and the shallow and deep pollution modes of polluted groundwater are described. Conclusions We adopt corresponding prevention and control methods for three types of mine water, and propose two prevention and control technologies, paste filling technology and microbial remediation technology. Through the application of actual mines as examples, it is confirmed that pollution prevention and control technology can improve the serious problem of groundwater pollution in river basins caused by coal mining, with the hope that the research results can have reference significance for successfully promoting the rapid development of green mines in China.

Abstract:This paper is the result of urban geological survey engineering. Objective Evaluating the geological environment resilience of urban deep underground space contributes to improving the safety of urban underground space during development and utilization, and reducing the economic losses caused by disasters. Methods In this paper, a multi-factor integrated evaluation model for the geological environment resilience of urban deep underground space was proposed from the aspects of the severity of event, the vulnerability of geological body, the resistant ability, the restoring ability and the adaptability. The evaluation model was applied to analyze a catastrophic engineering accident in a city by virtue of the relevant data. Results The evaluation model is highly operational and feasible, and can be used for resilience assessment of urban deep underground space with various complex geological environments. For the studied accident, the severity index of the event is 5.601, which is categorized as a severe level. The exposure index is 5.735, the sensitivity index to disaster damage is 6.146, and the vulnerability index is 35.247, so the geological body is vulnerable. The early warning capacity index is 1.00, the disaster prevention capability index is increased from 5.66 to 7.00, so the resistant index is increased from 15.38 to 19.02. The recovery is 2.00 after sand filling and grouting. The adaptability index is 1.00 because the geological environment tends to be stable. Conclusions If affected by a disaster, the evolution in the geological environment resilience can be divided into six stages, i.e., the normal stage, the affected stage, the resisting stage, the recovering stage, the adapting stage and the new normal stage. The resilience curve shows a decrease and then an increase before reaching stable again. The resilience level reaches a minimum value at the turning point of the affected stage and the resisting stage.

Abstract:This paper is the result of environmental geological survey engineering. 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 conduct rapid and efficient monitoring of land subsidence in the mining area. Methods Taking Datong coalfield as an example, the 31 scenes Sentinel-1 images 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 was verified using existing research results, and the spatiotemporal variation characteristics and evolution laws of subsidence were analyzed. Results The results indicate that the land subsidence in the Datong coalfield is extensively distributed, and its overall distribution of subsidence is basically consistent with the trend of mining management data. 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 severe. The subsidence characteristics of Datong coalfield mainly include the maximum subsidence rate of 168.03 mm/a, the maximum cumulative subsidence amount of 329.12 mm, and the total subsidence area of 270.95 km². Overall, there is a continuous increase in subsidence, and it takes a significant amount of time to achieve relative stability in surface activities in accordance with this trend. Conclusions This 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.

Abstract:This paper is the result of geological survey engineering. Objective Karst collapse is one of the main environmental geological problems in the Yangtze River Economic Belt. Conducting research on the distribution, causes, and impact on engineering construction of karst collapse in the Yangtze River Economic Belt is of great significance for the geological environment safety guarantee faced by the construction of multimodal transport corridor and urbanization in the Yangtze River Economic Belt. Methods This article systematically summarizes the survey results of karst collapse implemented by China Geological Survey since 2016, including the geological background, cause types and mechanisms, development and distribution patterns, impact on engineering construction, and prevention and control measures of karst collapse. Results The research results indicate that the area of potential karst collapse in the Yangtze River Economic Belt is about 254000 square kilometers, with 2146 documented karst collapse disasters events. Mine drainage, pumping and engineering construction are the main inducing factors for karst collapse in this area. The karst collapse in the Yangtze River Economic Belt has the following formation and distribution characteristics: firstly, it has regional and zonal distribution characteristics; The second is that the underlying strata are generally homogeneous pure carbonate rocks, distributed along strong karstification zones such as fault fracture zones, the axis of strata fold and contact zones between soluble and non-soluble rocks; Thirdly, it often occurs in areas with large amplitude, high speed, and high frequency of groundwater level fluctuation such as concentrated flow zone of karst and river terraces; Finally, it often occurs in areas with strong human engineering activities, and the scale and quantity mainly depend on the type and intensity of human activities. In order to reduce the impact of karst collapse on engineering, this article also proposes relevant suggestions and countermeasures. Conclusions The karst collapse in the Yangtze River Economic Belt is widely distributed and has a great impact. The planning and construction of linear engineering and Megalopolis in high risk areas should pay attention to this issue. The research results can provide basic support and theoretical basis for the spatial planning of the Yangtze River Economic Belt and the prevention and control of geological disasters.

Abstract:This paper is the result of hydrogeological survey engineering. 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 to 2018, 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, cropland, constructive land and forest increased by 1.58×10⁴ km², 1.2×10³ km² and 347 km², respectively. By comparison, grassland, unutilized land, water and wetland 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 constructive 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.

Abstract:This paper is the result of hydrogeological survey engineering. Objective The Beijing-Tianjin-Hebei Plain faces a serious shortage 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 effectively 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 This paper systematically carries out classified data statistics on supply directions, development and utilization models, and water supply scaleof unconventional water resources. We 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 5.43×10⁸ m³; Recycled water is mainly used in large industrial cities such as Beijing and Tianjin, with a water supply prospect of 34.22 ×10⁸ m³; Desalinated seawater is mainly used in Tianjin and other coastal cities, with a water supply prospect of 4.19 ×10⁸ m³; The use of rainwater is relatively scattered. Conclusions (1) There is a risk of soil salinization when brackish water is used for agricultural irrigation, and water and 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 obviously 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 rainwater 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.

Abstract:This paper is the result of environmental geological survey engineering. Objective With the continuous increase in socio-economic development and the urbanization rate, the ecological environment that supports mankind’s survival has been damaged and ecological vulnerability has become more serious. Therefore, ecological vulnerability evaluation has become a hot research topic. Since the industrial structure of the Oroqen Region changed from hunting to farming and livestock in the 20th century, the local ecological environment has been threatened and is likely to be vulnerable to further threats. Consequently, in this paper, the ecological vulnerability of the Oroqen Region was evaluated in three phases to provide a scientific basis for environmental protection and sustainable development. Methods The Oroqen Region in Inner Mongolia was selected as the study area, and 14 indicators were selected based on the SRP model, which were categorized into three types, namely ecological resilience, ecological sensitivity, and ecological stress. Then, Geographic Information System 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 the Oroqen Region in 2000, 2010, and 2020. Results (1) The overall ecological vulnerability of the Oroqen Region was a good-mild fragile state, the distribution area of the general fragile area remained stable for about three years, the moderately and severely fragile areas were mainly distributed in the south of Alihe, the south of Ulubuti, Dayangshu, and Guli, and there was an overall research deterioration trend. (2) The ecological vulnerability trend of the Oroqen Region was positive from 2000 to 2010, and the ecological vulnerability increased significantly from 2010 to 2020 when the ecological environment was damaged. Moreover, the area of severe ecological vulnerability that appeared for the first time in 2020 was 111.72 km², accounting for 0.51% of the study area. (3) The spatial distribution of the ecological vulnerability in the Oroqen area was mainly influenced by the biological abundance (D2), landscape diversity index (D3), elevation (D5), population density (D13), and other factors, and the influencing factors were more diverse in 2020. Furthermore, the two indicators SRPeading index (D4) and average annual precipitation (D12) had a strong driving effect on the local ecological vulnerability. Conclusions The ecological vulnerability of the Oroqen Region was low in the northwest and high in the southeast in 2000, 2010, and 2020, and the ecological environment became less vulnerable from 2000 to 2010 and deteriorated from 2010 to 2020. This was due to the continuous change in the natural conditions and the long-term influence of human activities. The ecological environment of the Oroqen Region is deteriorating in general.

Abstract:This paper is the result of environmetal geological survey engineering. Objective Wuyuan County is located in the Hetao Plain. To find out the heavy metal pollution status of the farmland soil in Wuyuan County, 1985 surface soil samples, 30 crop samples, and 5 drinking water samples were collected, and the contents of eight heavy metal elements, such As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn were analyzed and determined. Methods The heavy metal pollution degree and health risks of the soil, crops, and drinking water were evaluated using the soil accumulation index and Nemerow comprehensive pollution index methods and a health risk assessment model. Results The Nemerow comprehensive pollution index showed that the soil in this area was still largely unpolluted, and there was only light pollution of As in some areas. According to the human health risk assessment, ingestion of soil through the mouth or skin is a carcinogenic risk to residents (9.97×10^-6), and ingestion of As in drinking water is a certain health risk to residents (1.62). Conclusion Hg is greatly influenced by humans, and there were obvious strong anomalies in Sankou near the Ring Road in Wuyuan County. The other elements were mainly controlled by the parent material. The local content of As was high in Jianfeng Farm and other places, which exceeded the risk screening value. Thus, As contributed the most to the drinking water health risk and should be a cause for concern.

Abstract:This paper is the result of environmental geological survey engineering. 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. Conclusions 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.

Abstract:This paper is the result of hydrogeological survey engineering. 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 study 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 Contents 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 contents, pollution levels and potential ecological risks of heavy metals on the right bank were all higher than those on the left bank.

Abstract:This paper is the result of environmental geological survey engineering. 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 (P_Z), 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 P_Cd were at firstclass 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 P_As was at first-class cleanliness (94.24%), slight second-class pollution (5.04%), fourth-class medium pollution (0.72%). P_Z 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.

Abstract:This paper is the result of environmental geological survey engineering. Objective The investigation of the geochemical behavior of heavy metals in the surface geochemical process has important guiding significance for the construction of life community of mountains, rivers, forests, fields, lakes and grasses. The purpose of this study is to investigate the geochemical behavior and driving mechanism of soil heavy metals in the middle-alpine hilly region of southwest China. It will serve the implementation of the strategy of plateau characteristic agricultural development and rural revitalization. Methods Based on 1∶250000 land quality geochemical survey data in Dayao County, Yao'an County and Nanhua County in central Yunnan Province, the source, spatial distribution pattern and driving mechanism of soil heavy metals were analyzed by geostatistics, and the driving model of soil epigenetic geochemical process of heavy metals was established in the middle-alpine hilly region of southwest China. Results The results showed that the average content of Cd and Hg in the surface soil in the study area was higher than the background value of the deep soil, Cr and Ni were higher than the background value of the soil in Yunnan province, and other heavy metals except As, Hg and Sb were significantly higher than the national background value of the soil, and local soil may have ecological risks of As, Cd and Pb. The elements of the constructed minimum dataset are As, Co, Cr, TFe, Ni, Pb, Sb, Sn, V and Zn, and the Moran index shows significant positive spatial autocorrelation. The spatial distribution features high content of heavy metals in metamorphic rocks and intrusive rocks, low content of clastic rocks and quaternary alluvium. Multivariate statistical analysis and spatial distribution characteristics of heavy metals show that Co, Cr, TFe, Mn, Ni and V mainly come from the parent material, As, Sb and Sn are greatly affected by the primary strata and metallogenic geological background, Cd, Pb and Zn are mainly affected by human activities such as industrial and mining activities. Conclusions The distribution of heavy metals is highly coupled with the ground distribution. The spatial distribution pattern of heavy metals in surface soil is controlled by geological background, and the content of heavy metals in soil varies significantly among different soil types and land use types. The vertical migration and enrichment of heavy metals are driven by rock weathering, and the heavy metal content and elevation show a significant polynomial linear fitting trend. Organic matter and pH are the main factors controlling the heavy metal behavior at different elevation intervals. Strong epigenetic geochemistry in the study area reshaped the macroscopic distribution of heavy metals. Restricted by their own chemical properties and influenced by environmental conditions (slope, pH, organic matter, etc.), distribution, migration and enrichment of heavy metals occurred in the soil. Human activities affected the distribution pattern of local heavy metals.

Abstract:This paper is the result of environmental 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 Based on the grid distribution point method, 497 soil samples were collected in June 2021 in typical coal mining areas, and soil pH, SOM, As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were analyzed. The Pollution Load Iindex method (PLI) and the Potential Ecological Risk Index method (PERI) were used to evaluate the status of heavy metal pollution and potential ecological risks. The potential sources of heavy metals were analyzed by using Principal Component Analysis (PCA) and positive definite matrix factor analysis (PMF) models. Results The soil is mainly acidic, the average pH value of the soil is 5.39, and the average of SOM content is 1.20 times that of the background value for soils in Yunnan Province. The average and median values of Cr, Cu, Cd, Ni, Zn and Hg contents exceed the soil background values in Yunnan Province. The vast majority of sampling points have Cd, Cu, Cr, Ni content exceeding the risk screening value, accounting for 94.97%, 93.96%, 91.35%, and 79.28%, respectively. A small number of sampling points have As and Cd content exceeding the control values, accounting for 0.20% and 1.41%, respectively. The evaluation results of the PLI showed that the study area as a whole shows slight pollution. The evalution results of PERI showed that the overall risk of the study area is moderate. The results of the PCA and the PMF model analysis showed 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 risks of Cd and Hg in the soil of the coal mining areas area relatively high, and the heavy metals in the soil 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.

Abstract:This paper is the result of geothermal geological survey engineering. Objective In order to develop and use geothermal water resources in western Sichuan rationally, it is important to study hydrochemical characteristics and genetic models of the geothermal waters spatially linked with the Xianshuihe (XFZ), Anninghe (AFZ), and Longmenshan (LFZ) fault zones. Methods The methods of hydrogeochemistry, reservoir temperature calculation, hydrogen and oxygen isotopes were used to estimate hydrochemical types, hydrochemical processes, reservoir temperatures and depths, and recharge sources of 48 typical localities of geothermal waters (or geothermal springs or drilling holes) located around these three fault zones, and reconstruct the mode of their formation. Results (1) Hydrochemically the geothermal waters are dominated by HCO₃-Na type in the XFZ, SO₄-Na and Cl-Na types in the LFZ and HCO₃·Cl-Na, HCO₃·SO₄-Ca·Mg and Cl·SO₄-Na types in the AFZ. (2) The composition of geothermal waters of the three fault zones are mainly controlled by the dissolution of silicate minerals and ion exchange process. (3) The temperatures of the reservoirs, their depths and the cold water mixing ratio are, respectively, 129.6-210.6℃, 2532-4184 meters, and 66%-82% for the XFZ, 81-121.9℃, 2155-3519 meters, and 52%-95% for the AFZ and 108.2-153℃, 3573-5654 meters, and 68%-89% for the LFZ. (4) The geothermal waters in the three fault zones are recharged by meteoric waters derived from elevations at 2493 to 5034 meters in the XFZ, 3235 to 3839 meters in the AFZ, and 1628 to 4574 meters in the LFZ. (5) The degree of the “δ¹⁸O drift” of geothermal waters in the XFZ is higher than that in the AFZ, and the geothermal waters in the LFZ exhibit characteristics of “δ¹⁸O drift” and “negative drift”. Conclusions Our results show that among the three perspective areas of the Sichuan Province, the Xianshuihe Fault Zone possesses a higher commercial potential for the exploration and utilization of medium-high temperature geothermal resources compared to the Anninghe and Longmenshan fault zones.

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