Abstract:This paper is the result of hydrogeological survey engineering. [Objective] The southern Xinjiang is characterized by an important mineral and energy base and a key area of many national strategies. Water resources shortage is a key factor that hinders the social and economic developments as well as ecological protection and restoration in the southern Xinjiang where the climate is arid. To secure sustainable water resources development and environmental protection, identifying water- related issues and taking countermeasures are required. [Methods] Through a systematic synthesis on previous studies, the current status, issues and countermeasures of water resources development will be discussed. [Results] Water resources originate from the mountainous regions where rivers receive precipitation and snow (glacier) melting water contribution. The interaction between groundwater and surface water is frequent after rivers flow out of the mountains and water resources are consumed by evaporation finally at lowest reaches. The mean annual water resources are 4.51 × 10¹⁰ m³ among which surface water resources are 4.32×10¹⁰ m³, groundwater resources are 2.68×10¹⁰ m³, and the overlapping resources are 2.49 × 10¹⁰ m³. The consumption in recent years reaches 3.27 × 10¹⁰ m³, corresponding to a development level of over 70% that significantly exceeds the alarming level. The development rate indicates that water resources are over-used currently. Surface water quality is good in general, water quality superior to the third category accounts for 94%. Groundwater water quality becomes worse from the piedmont plains to the heart of the basin, and decreases from Ⅰ-Ⅲ level to Ⅳ-Ⅴ level (high total dissolved solids). In some areas, common elements and organic pollutants exceed the safety levels. The main problems related to water resources development are low efficiency and output of water resources, salinization and desertification due to unreasonable water development, high uncertainty on ecological water use and limited studies on the impact of climate change on water resources. [Conclusions] Aiming to solving these questions, water-saving agriculture and saline water use should expand, the water allocation among different reaches (upper, middle and lower) and sectors (human, ecology and production) should be considered and detailed studies on the impact of climate change on water resources and on the ecological water demand should be carried out.

Abstract:This paper is the result of hydrological geological survey engineering. [Objective] As an important first-class tributary of the Yellow River Basin, it is also an important functional area for soil and water conservation, the Qinhe River Basin is facing two sensitive environmental problems, water environment destruction and soil erosion. Environmental sensitivity evaluation is an important measure of external interference with natural ecosystems. It plays an important role in carrying out regional ecological protection. [Methods] Based on the different environmental geological problems faced, the evaluation methods of analytic hierarchy (AHP) and RUSLE models were selected. Moreover, combined with the powerful spatial analysis function of GIS spatial data technology, sensitivity evaluation maps were generated by integrating graph processing and spatial data operation. The evaluation results were intuitive, which provided technical support for environmental sensitivity analysis. [Results] After assessment, it can be divided into four types of sensitive areas, that is, mildly sensitive areas, moderately sensitive areas, highly sensitive areas and extremely sensitive areas. Statistical analysis shows that moderate and highly sensitive areas account for the largest proportion, reaching 33.43% and 48.56% of the total area, respectively. At the same time, based on each tributary basin, the author puts forward the corresponding adjustment plans to the causes and improvement methods of the environmental status, aiming at the main environmental problems facing each type of sensitive areas. [Conclusions] According to the environmental conditions and sensitivities of each region, the ecological environmental protection and restoration idea was put froward, and an ecological network pattern combining mountain and plain ecosystems is constructed to improve the ecological environment of the Qinhe River Basin.

Abstract:This paper is the result of hydrogeological survey engineering. [Objectives] The Yellow River irrigation area of Ningxia is one of the important grain production bases in China. Since the implementation of water-saving irrigation, projects such as canal lining and field water-saving have affected the regional water balance. It is of great significance to study the influence mechanism and ecological effect of water- saving irrigation on water balance for the optimal management of regional water resources. [Methods] By constructing the water- soil- gas- generation diversified database of the Yellow River irrigation area of Ningxia, adopting rank correlation analysis and Spearman correlation analysis methods, the evolution trend of water balance elements, water balance evolution mechanism and ecological effect of the Yellow River irrigation area of Ningxia from 2000 to 2020 were studied. [Results] The economic development of the Yellow River irrigation area of Ningxia mainly depends on the Yellow River water. Since the implementation of water-saving irrigation, the water circulation flux decreased significantly. From 2000 to 2020, the amount of agricultural water intake, water diversion and water discharge decreased by 21.38×10⁸ m³, 19.52×10⁸ m³ and 19.11×10⁸ m³, respectively. Water-saving irrigation is the main driving factor of water balance evolution, and the decrease of agricultural water intake directly leads to the decrease of the amount of water diversion and groundwater recharged by surface water (P<0.01). After the implementation of water-saving irrigation, the amount of groundwater recharged by surface water decreased by 8.68×10⁸ m³, and the amount of groundwater resources decreased by 8.89×10⁸ m³. The groundwater table decreased, and the degree of salinization reduced. In addition, the decline of the groundwater table changed hydraulic connection between lakes and groundwater, resulting in an increase in ecological water demand. [Conclusions] After the implementation of water- saving irrigation, the utilization efficiency of agricultural water has been improved, water circulation flux has been significantly reduced, and the decline of groundwater table has affected the ecological environment. It is suggested to further optimize the water-saving scheme based on ecological security. Relevant research results provide support for regional natural resource management and ecological protection and restoration.

Abstract:This paper is the result of environmental geological survey engineering. [Objective]Small- scale drainage catchment in mining areas usually have natural high geological background values of heavy metals, therefore, the traditional unified reference value or standard value for heavy metal pollution assessment can no longer meet the requirements of ecological environment service function impact assessment, land restoration management, and soil restoration requirements in the process of mine ecological environment supervision. It is of great significance to carry out investigation and evaluation of heavy metal pollution in the mining area of shallow mountain areas under the guidance of scientific theory of earth system. [Methods]The crux of soil heavy metal pollution and ecological risk assessment in mountainous areas lies in the division of survey and evaluation units-the division of survey and evaluation scales, the determination of assessment criteria-the establishment of geochemical baselines, and the establishment of assessment mathematical models.The investigation and evaluation unit dividing method, as well as three methods for determining assessment criteria for heavy metal pollution including environmental quality standard, geochemical baseline and ecological effect method were reviewed in this article. [Results] The classification, applicability and development status of heavy metal pollution and ecological risk assessment models, application of new techniques and methods for geochemistry baseline survey and evaluation of soil heavy metal were summarized for evaluation of heavy metal pollution in the mining area. [Conclusions] All these reviews were aiming to provide reference baseline, quantitative ruler and method support for determine the baseline geochemical characteristics of heavy metals in the disturbed environment, tracing back the background characteristics of heavy metals, revealing the sources of pollution and the mechanism of migration and transformation of heavy metal, and methods for early warning of ecological environment pollution and ecological environment restoration support.

Abstract:This paper is the result of environmental geological survey engineering. [Objective] Effect of pyrolysis temperature and raw materials on adsorption of heavy metals by straw-based biochar. [Methods] Corn straw and rice straw were used as raw materials to prepare straw based biochars (i.e. S450, S600, Y450, Y600) under anoxic conditions at 450℃ and 600℃. And the differences in their surface characteristics and their adsorption capacity for Pb²⁺ and Cd²⁺ in solutions were studied. [Results] The results showed that the pyrolysis temperature had a significant effect on the physicochemical properties of different biochars. With the increase of pyrolysis temperature, the C contents of biochars increased, but N, H, O contents decreased. Besides, their specific surface area, total pore volume and average pore diameter all showed a decreased tendency. As the result of the increase of pyrolysis temperature, the adsorption capacity and rate of Pb²⁺ and Cd²⁺ increased. Meanwhile, the adsorption capacity of Pb²⁺ and Cd²⁺ of corn straw biochar was significantly higher than that of rice straw biochar. The adsorption of Pb²⁺ and Cd²⁺ by the four biochars was dominated by chemical precipitation. [Conclusions] The adsorption of Pb²⁺ and Cd²⁺ was mainly multilayer and monolayer adsorption, respectively. Straw based biochars with higher pyrolysis temperature had higher adsorption capacity for Pb²⁺ and Cd²⁺. This study is useful for straw resource utilization and heavy metal pollution remediation.

Abstract:This paper is the result of environmental geolgical survey engineering. [Objective] In order to support and provide a scientific plan for coastal ecological protection and restoration, it is necessary to figure out the laws and trend of natural coastal evolution processes. [Methods] Based on systematic collection and summarization of achievements on the evolution of the mainland coasts of China, combined with drilling cores comprehensive research, remote sensing interpreting and ArcGIS spatial analysis, the coastal history since the Last Glacial Maximum (LGM) was quantitatively reconstructed. [Results] The results showed that seawater frequently entered and exited the coastal areas since 2 million years ago. The last large- scale transgression- regression occurred in the past 20 ka, which can be divided into three phases: the coasts experienced the LGM-early mid-Holocene transgression, the Early mid-Holocene-1850 CE regression, and a new transgression again since ca. 1850 CE. [Conclusions] According to the analyzed results of the existing instrumental data, the coasts of the Chinese mainland and the world will face accelerating sea-level rise, increasing coastal erosion, and increasing storm surge threats in the future, which will be a key issue of ecological protection and restoration. In view of this, the following suggestions are put forward for the ecological protection and restoration of the coastal zone: First, for sandy coasts, while following the overall natural erosion background, the appropriate restoration strategies should be applied to the shore section with important ecological and economic values, and to avoid large-scale over-repair; The second is to determine scientifically feasible restoration targets in view of the squeezing of the mangrove ecological space caused by sea level rise and coastal erosion; The third is to strengthen the construction of ecological seawalls in the muddy coastal lowland areas.

Abstract:This paper is the result of environmental geological survey engineering. [Objective]Soil heavy metal pollution is the main factor that causes the decline of soil ecological environment quality, crop heavy metal exceeds the national standard and even endangers human health. Mining and smelting activities are the primary source of soil heavy metal pollution. China's domestic metal mines have relatively low-grade and are expensive to process. The mining process produces a large amount of toxic and harmful heavy metals into the soil, which causes severe soil heavy metal pollution due to mining activities. At present, finding suitable methods to remediate heavy metal contaminated soils in mining areas is a hot issue and complex research area in environmental science. [Methods]This paper reviews the characteristics, hazards and remediation technology of heavy metal pollution in mining soils by many relevant literatures. [Results]The current remediation methods for soil heavy metal pollution in mining areas include: (1) engineering remediation technology: guest soil method; (2) physical remediation technology: electro kinetic remediation, vitrification method and heat treatment method; (3) chemical remediation techniques: soil leaching and fixation; (4) bioremediation technology: phytoremediation and microbial remediation method. [Conclusions]The guest soil method is the most widely used and effective treatment technique, and phytoremediation technology is the best application prospect. A single remediation technique often has certain limitations in the actual remediation of heavy metal contaminated soil in mines. It cannot meet the remediation needs, so a combined remediation method combining multiple remediation techniques can complement each other to achieve the best remediation effect.

Abstract:This paper is the result of mineral exploration engineering. [Objective] In recent years, the new energy industry sees a robust growth with strong demand for lithium batteries and fierce competition for lithium resources. Compared with hard rock-type lithium deposits, which are currently the main type for lithium exploitation, salt lake brine-type lithium deposits have the advantages in reserves, environment-friendly and financial benefit. With the continuous improvement of lithium extraction technology from brine, the production capacity of salt lake brine-type lithium deposits will be further released. China is one of the countries where salt lake brine-type lithium deposits are mainly distributed, and the resources reserves is ranked 5th around the world. In the world-wide fierce competition for lithium resources, it is of great significance to summarize distribution regularity, hydrochemical classification and mineral combination of salt lake brine- type lithium deposits, while estimating potential resources and proposing an evaluation methods for salt lake brine-type lithium deposits also contribute to the arrangement of protesting and exploitation investment and the scheduling of new energy resources in our country. [Methods] We collect the published data of salt lake brine-type lithium deposits, analyze the basic characteristics from the aspects of distribution and geological conditions of metallogenesis, and systematically summarize the estimation of potential resources and evaluation the potential in exploitation. [Results] Lithium resources from salt lake brine-type deposits are abundant in the world, but the distribution is uneven. Salt lake brine-type lithium deposits are mainly located in the three major plateaus, namely the Andes Plateau in South America, the western Plateau of the United States and the Qinghai-Tibet Plateau of China. The genesis is mainly controlled by tectonic background, fault activities, climate and altitude. The difference between salt lake brinetype lithium deposits in the Qinghai- Tibet Plateau and those in other two salt lake accumulation areas is that the tectonic background of the Qinghai-Tibet Plateau is continental collision rather than oceanic crust subduction. The salt lakes in the QinghaiTibet Plateau can be further divided into two parts: the Tibet salt lake area and the Qinghai salt lake area from south to north. On the one hand, the salt lakes in Qinghai area has high Mg/Li ratio, so the exploitation is not suitable for the traditional evaporation precipitation method. On the other hand, new emerging lithium extraction methods cost high, as a result, the exploitation and technical conditions need to be evaluated carefully. [Conclusion] Based on the published data, the ore-bearing coefficient“N”and harvest coefficient“HI”of three salt lake accumulation areas are calculated and the general formula for estimating the potential resources is also established. By considering the key points of exploitation evaluation of salt lake brine-type lithium deposits, the quality of lithium deposits in world-famous salt lake areas is evaluated by using the“lg(Li ⁺)-lg(Mg/Li) combining the price of lithium carbonate discriminant diagram”. The results show that if the price of lithium carbonate is below 100,000 yuan/ton, the quality of salt lakes is ranked as follows: Tibet, China > Andean Plateau of South America > Western Plateau of the United States > Qinghai, China; if the price of lithium carbonate goes above 100,000 yuan/ton, the order changes to: Andean Plateau of South America > Tibet China > Qinghai China > Western Plateau of the United States.

Abstract:This paper is the result of mineral exploration engineering. [Objective]In the context of the global energy transition, the demand for nickel is growing rapidly and the price continues to rise. Finding more nickel metal resources to satisfy economic development is an important task of the current geological community. [Methods]The study summarized the genetic type, metallogenic age, metallogenic characteristics and geological background of nickel deposits, sorted out the global nickel reserves and mine production, and estimated the supply current situation and consumption trend of nickel metal, with the aim to provide background knowledge (information) for the search of new nickel deposits. [Results]The economically significant nickel deposits in the world include magmatic and weathered crust types. The magmatic type nickel deposit is mainly distributed in Canada, Australia, Russia and China, and the weathered crust type nickel deposit is mainly distributed in Indonesia, New Caledonia, Brazil and Philippines. [Conclusions]In order to alleviate the contradiction between supply and demand of nickel resources, we should achieve in the allocation of global nickel resources, strengthen the effective supply, increase exploration efforts, improve resource utilization efficiency, and build a recycling system.

Abstract:This paper is the result of mineral exploration engineering. [Objective]The global rhenium resources are unevenly distributed. Chile accounts for more than half of the total global rhenium resources, mainly from porphyry copper deposits. The type of rhenium deposit is closely related to its occurrence state. Since most of the rhenium ore is associated with other minerals, the classification of rhenium deposits has not yet formed a unified standard, which can not provide a basis for ore prospecting. Therefore, it is urgent to carry out relevant research. [Methods]In this paper, from the perspective of global occurrence of rhenium deposits, ore types and other aspects, the enrichment and mineralization rules and deposit types of existing typical rhenium deposits are systematically sorted out and summarized, in order to provide ideas for the exploration and development of this type of deposits. [Results]Rhenium deposits are divided into four types in this paper: rhenium in porphyry copper deposits, rhenium in sedimentary- type strata- bound copper deposits, rhenium in sandstone- type uranium deposits, and rhenium in skarn deposits. Among them, rhenium in porphyry deposits has the highest grade and largest reserves. In terms of metallogenic characteristics, the Yanshanian period is the most developed for rhenium mineralization, followed by the Himalayan, Indosinian, and Caledonian periods. Large associated rhenium deposits mainly developed in the Caledonian, Indosinian, Yanshanian and Himalayas. In terms of rhenium exploration, more than half of the proven rhenium reserves are from Chile, and the remaining major countries are the United States, Russia, Kazakhstan and Armenia in order. Regarding the development of rhenium ore, rhenium ore is likely to exist in porphyry copper deposits formed in a continental arc environment, and many countries have begun to recover rhenium from porphyry copper deposits. [Conclusions]As an emerging resource, rhenium ore will play an active role in the implementation of energy saving, emission reduction, and carbon neutrality in the future. The exploration of independent rhenium deposits and the genetic mechanism of copper-molybdenum- rhenium associated deposits should be strengthened, and the secondary development and utilization of old mines should be emphasized.

Abstract:This paper is the result of mineral exploration engineering. [Objective] Silver is an indispensable material for modern national defense and cutting-edge science and technology. It is also one of the precious metals used by the people to decorate and beautify their lives. [Methods] This paper systematically collected the reserves and distribution of silver deposits in Hunan province. Based on the systematic sorting out of 93 silver deposits in Hunan province, we comprehensively analyze the genetic types and main prediction types of silver deposits in Hunan, and the metallogenic control factors such as strata, structure, magmatic rocks, geochemical anomalies and heavy sand anomalies. Furthermore, the temporal and spatial distribution law of silver deposits in Hunan is also summarized. [Results] By 2018, 93 silver deposits were discovered in Hunan province, with a total of 15,500 tons of resources identified. The identified resources in Hunan accounted for 4.71% of the silver deposits in China. Chenzhou, Hengyang and Yongzhou accounted for 89.40% of the total identified resources in Hunan. Silver is mainly associated with lead, zinc, gold, copper and tungsten, with associated deposits as the main ones, paragenetic deposits and main deposits as the auxiliary ones. These deposits can be divided into six genetic types: skarn type and magmatic hydrothermal type formed by magmatism, epithermal medium- low temperature (MVT Mississippi Valley) type formed by orebearing fluid, mechanical sedimentation (sandstone) type and chemical sedimentation (shale) type formed by sedimentation, and prediction type formed by supergene weathering. Among them, skarn type, magmatic hydrothermal type and epithermal mediumlow temperature type are the main genetic types and prediction types. The distribution map of main prediction types of silver deposits in Hunan is compiled. [Conclusions] Four metallogenic epochs are divided into Caledonian, Indosinian, Yanshanian and Himalayan, and Yanshanian is the main metallogenic epoch. In space, silver mines are distributed all over the Hunan province except from Dongting Lake, mainly distributed in the east of Yueyang—Shaoyang line. The resource reserves are mainly distributed in Qibaoshan, Shuikoushan, Qianlishan, Pingbao and Tongshanling. 23 ore concentration areas are divided, subdivided into 7 metallogenic series and 8 subseries. The distribution map of silver ore concentration areas in Hunan province are compiled.

Abstract:This paper is the result of hydrogeological geological survey engineering. [Objective]In order to study the hydrochemical characteristics and evolution of groundwater in the Ejina plain, Inner Mongolia, 87 water quality samples and 69 hydrogen and oxygen isotope samples were collected in August 2020. [Methods]Based on the methods of mathematical statistics, ion ratio, and hydrogeochemical simulation, the hydrogeochemical characteristics and the hydrochemical evolution rule of groundwater stored in Quaternary aquifer and Cretaceous aquifer were analyzed. [Results]The results showed that: (1) The groundwater was mainly SO₄-Na type. SO₄^2- was the main anion, followed by Cl^-. Na⁺ was the main cation, followed by Ca²⁺ and Mg²⁺, there was little difference between Ca²⁺ and Mg²⁺ concentrations. (2) The concentrations of SO₄^2-, Cl^-, TDS, total hardness, Na+ and Mg²⁺ decreased in the order of Quaternary confined water> Quaternary phreatic water> Cretaceous confined water. (3) Quaternary phreatic ions were mainly controlled by leaching and mixing process, and some areas were significantly affected by evaporation. The ions of Quaternary confined water were mainly controlled by leaching and cation exchange. The ions of the Cretaceous confined water in the northern part of the plain were controlled by leaching and cation exchange. The main ions of groundwater in the study area came from the dissolution of halite, carbonates and gypsum. [Conclusions] Along the direction of groundwater flow, the concentration of ion components in Quaternary phreatic showed an increasing trend. In the Quaternary phreatic and confined water in the Ejina plain, the main water- rock interaction processes were dissolution of halite, dolomite and gypsum, precipitation of calcite, and positive cation exchange. In the interlaced zone between the desert and the plain in the southeast of the study area, the dissolution of halite, dolomite and gypsum, the precipitation of calcite, and reverse cation exchange mainly occurred. Halite, dolomite and gypsum dissolution, calcite precipitation, and positive cation exchange mainly occurred in the Cretaceous confined water in the northern plain.

Abstract:This paper is the result of mineral exploration engineering. [Objective]The potash deposit in Laos is one of the most important potash deposits in the world. To carry out studies of the sedimentary environment during the precipitation of potassium minerals is very significant for a deep understanding of the mineralization of potash deposits here. [Methods]The insoluble minerals in the potash seams, which can retain more original information than soluble salts, is an important carrier for studying the evolution of ore- forming brine. Systematic studies on insoluble minerals in borehole ZK16 from the Haixiafeng mining area of the Vientiane Basin of Laos were conducted through microscopic identification, XRD, and SEM. [Results]Analysis results show that the insoluble materials mainly include anhydrite, boracite, hilgardite, quartz, dolomite, magnesite, calcite, and muscovite, in which anhydrite and boracite are dominant minerals. The existence and distribution characteristics of authigenic quartz and clastic muscovite reveal that continental waters have affected potash deposits to different degrees during deposition. [Conclusions]Comprehensive studies show that the process of potassium salt deposition in the study area can be divided into four distinct stages: fluctuation deposition stage, shallow water deposition stage, stable deposition stage, and reworking stage.

Abstract:This paper is the result of geological survey engineering. [Objective] The groundwater in Lianhuashan area of Changchun is rich in strontium and metasilicic acid. It is important to understand the formation mechanism of strontium and metasilicic acid in groundwater. [Methods] The material basis, hydrodynamic conditions and hydrochemical conditions of the formation of mineral water in the study area were studied in depth by using the Piper three-line diagram method. [Results] It is found that the loose rock, clastic rock and igneous rock developed in Lianhuashan area of Changchun are the material basis for the enrichment of strontium and metasilicic acid in groundwater in this area; Atmospheric precipitation and infiltration recharge of surface water create conditions for the long-term hydrolysis and leaching of groundwater with surrounding rocks (minerals), and for the final enrichment of strontium and metasilicic acid in groundwater. [Conclusions] There is a 16.3- 80 m thick bedrock weathering zone in the regional strata, which makes the groundwater rich in strontium and metasilicic acid distributed in a plane shape. In some areas, two kinds of groundwater exist at the same time, which is different from the linear distribution of mineral water resources found in the bedrock structural belt; No one in history has found mineral water rich in strontium and metasilicic acid in this area. This discovery provides imagination space for local economic development.

Abstract:This paper is the result of ecological geological survey engineering. [Objective]The origin and enrichment of trace elements such as Cd and As in soil- water- atmosphere dust fall are the focus of environmental geology research. The quantitative research on migration and enrichment of trace elements such as Cd and As in soilirrigation-rain-atmosphere dust fall system was carried out in Huishui. It is of great significance for agricultural production and agricultural products planting in this region. [Methods]Taking the samples of surface soil, irrigation water, rainwater and atmospheric dust- fall from Huishui County of Guizhou Province as research objects, this paper analyzes the geochemical characteristics of trace elements such as Cd and As. [Results] The results show that the study area is dominated by acid soil. Cd is positively correlated with As, Cr, Hg, Mn, Ni, Pb, Zn and pH while it is negatively correlated with Cu and Se in the 147 topsoil elements. The 34 irrigation water samples are mainly As, B, F^-, Se and Zn. The single factor pollution index and Nemero composite index of heavy metal elements from irrigation water are Level 1, belonging to the clean range, which indicates that the water quality of irrigation water is up to the standard. Among the 5 rainwater and atmospheric dust-fall samples, the atmospheric dust-fall mainly includes As, Cd, Cr, Hg and Pb and the main components of rainwater are As, B, Cd, Cr⁶⁺, F^-, Ge, Hg, Pb, Se and Zn. [Conclusions] The evaluation results show that the Cd single factor pollution index is the highest, and the Nemero composite pollution index is arranged as followed: Hongqi Village, Xiantang Town>Yangma Village, Lushan Town>Lianjiang Street, Dapo Village>Haohuahong Village, Haohuahong Town>Lixin Village, Baijin Town. The irrigation water quality reaches the standard without heavy metal pollution. The order of the average annual flux density of atmospheric dust- fall is B>Se>Pb>Zn>Cr>As>F>Cd>Ge>Hg. The average total amount of atmospheric dust-fall in the study area is 89 g·m^-2·a^-1, which is slightly lower than that of some cities and provinces in China. The comparison between surface soil and atmospheric dust-fall shows that Cd, Cr, Pb, Zn are rich and Se is poor in terms of the comparison between surface soil and annual rainwater flux, indicating that rainwater contributes largely to Se. Compared with rainwater, elements in the atmospheric dust-fall are higher except Hg. Compared the atmospheric dust-fall annual flux to the average surface soil, all elements are in deficit except Se. And compared the atmospheric dust-fall annual flux to the irrigation water contents, As, Hg, Se are enriched while Cr is depleted. So it can be concluded that the heavy metal element Cd pollution in surface soil comes from geological background, industrial wastes and coal burning while the atmospheric dust- fall mainly comes from coal burning dust and traffic dust.

Abstract:This paper is the result of environmental geological survey engineering. [Objective] Eastern Yunnan is an important coal base in southern China. To reveal the sources and ecological risks of heavy metals in sediments of small watersheds in typical coal mining areas is of great significance for the protection and treatment of ecological environment in coal mining areas. [Methods] The surface sediment samples were collected from small watersheds, and total contents of As, Cd, Cu, Pb, Hg, Mn, Ni, Cr, Zn and V were determined. The pollution degree and potential ecological risk of the heavy metals were evaluated by the geo- accumulation index and potential risk index, and their potential sources were analyzed based on mathematical statistics method. [Results] The results shows that the heavy metals in the sediments of small watershed exceed the soil background value of Yunnan Province except As and Pb, but only the average content of Cu exceed the risk screening value. In terms of spatial distribution, Cr, Ni and V are of medium variation while the other heavy metals are of highly variation. The pollution degree of each heavy metal can be ranked as Cr > Cu > Cd > Mn > Zn > V > Ni > Hg > Pb > As, in which the pollution of Cr is of moderate degree, the pollution of Cu, Cd, Mn, Zn, V and Ni are of mild degree, and the pollution of As, Pb and Hg are clean and pollution-free. The potential ecological risk of heavy metals in sediments presents a low risk to medium risk. Cd and Hg are the main ecological risk factors, showing moderate risk, while the ecological risk of other heavy metals is relatively low. The results of correlation analysis, principal component analysis and cluster analysis show that the contents of heavy metals in sediments are controlled by human activities and natural background, in which Mn, Ni, V and Cr are mainly from natural sources, As, Hg, Cd and Pb are mainly from man-made sources, and Cu and Zn are comprehensively affected by both of natural and manmade sources. [Conclusions] Although the study area is a typical geological high background area in eastern Yunnan, the potential risks caused by human activities such as coal industry to the ecological environment quality of sediments in the basin cannot be ignored, especially the monitoring and treatment of Cd and Hg.

Abstract:This paper is the result of ecological geological survey engineering. [Objective] In order to find out the pollution status of two heavy metals vanadium and cobalt in the surface soil (0- 20 cm) in Tongbai- Biyang area, 5521 topsoil samples were collected to analyze and determine the content of heavy metals V and Co. [Methods] The distribution characteristics, ecological risk, health risk and influencing factors of V and Co in soil were studied by using the single-factor index method, geoaccumulation index method and human health risk assessment method. [Results] The results show that the V and Co in the study area were distributed in patches, and the area with high V and Co content was mainly in the south of the area. By assessing the single-factor pollution index and the geo-accumulation index, we found that there were more Co samples than V ones, and some samples had both elements. The human health risk assessment results show that adults are at a higher risk than children. The non-carcinogenic risk index of all V samples for adults was more than 1, while 99.06% of that for children was more than 1. The main route of non-carcinogenic risk transmission was through respiratory inhalation. 32.95% of Co samples for adults were deemed not acceptable regarding non- carcinogenic risk, while the figure for children was 19.74%. The carcinogenic risk indexes for both adults and children were within acceptable ranges. And the southern part of the area presented high non-carcinogenic and carcinogenic risk indexes for adults and children. [Conclusions] The content of V and Co in soil was affected by not only soil clay, pH value as well as iron and manganese oxides, but also human activities. Mining in the study area may be the main cause of V and Co soil pollution and health risks.

Abstract:This paper is the result of environmental geological survey engineering. [Objective] Copper (Cu) is an essential trace element for humans, while moderate intake of Cu is important, deficiency or overdose of Cu can also be harmful to human health. Therefore, it is important to determine the optimal range of Cu content in agricultural products and soil by knowing the range of daily Cu intake for each person to safeguard human health. [Methods] In this paper, taking the Qintang District of the Guigang City of Guangxi as the study area, based on the investigation results of the dietary structure survey of the residents in Guangxi and the Cu content in the soil, crops, and root soil obtained from the 1∶50000 land quality geochemical survey, the characteristics and spatial distribution of Cu content in the soil and rice were studied, the influencing factors of Cu absorption by rice are analyzed. A prediction model for the Cu content of rice was proposed and derived the optimal range of soil Cu content was for the safe development and cultivation of rice in the study area. [Results] The results showed that the soil Cu content in the study area ranged from 6~74 mg/kg, with mean and median values of 28 mg/kg and 26 mg/kg, respectively. Only 1.6% exceeded the risk screening value of Cu content specified in GB15618, and it is mainly distributed in the carbonate rock outcropping area. Fe-Mn nodules are widely distributed in this area, and the soil's biological activity of heavy metals such as Cu is relatively low. The range of rice Cu content in the study area is 0.790~4.440 mg/kg; the mean and median values are 2.452 mg/kg and 2.718 mg/kg, and 60 rice samples do not exceed the limit value of Cu specified in NY861- 2004. [Conclusions] To protect human health and reduce ecological risks, the optimal range of copper intake in rice is 0.615~8.204 mg/kg. The prediction model of Cu content in rice is established, and it is concluded that the optimal range of safe development of copper in soil and rice cultivation is 6~84 mg/kg.

Abstract:This paper is the result of mineral exploration engineering. [Objective] As a kind of metal mineral, manganese ore is used in many fields of national economy. Qianyang manganese-forming basin is an important manganese ore base in China. Th type of manganese deposit is a set of marine manganese carbonate deposits occurring in the strata of Datangpo Formation of Nanhua System, with large resource reserves and long mining history，but its metallogenic model is still unclear. [Methods] This paper takes Jingzhou area of Hunan Province as an example, where manganese deposits are concentrated. On the basis of field profile measurement and geochemical data analysis, the sources of manganese in manganese ores are analyzed by Co/Zn-(Cu+CO+Ni) diagram, Fe-Mn-(Cu+CO+Ni)×10 three-terminal discriminant diagram, (Zr + Ce + Y) × 100- (Cu + Ni) × 15- (Fe + Mn)/4 ternary diagram, Al/(Fe + Mn + Al) ratio, (Fe + Mn)/Ti ratio and Fe/Ti ratio. The paleoenvironment of manganese ore deposition was analyzed by using V/Cr, Th/U, Ce/La and Ce markers of manganese ore. [Results] The manganese element in the manganese ore in Jingzhou area of Qianyang manganese basin mainly comes from the seafloor hydrothermal system, and the water body is in the oxygen-poor-anoxic environment at the time of deposition. The fault zone formed in the early stage provided a channel for manganese migration. [Conclusions] The manganese ore in Jingzhou area of Qianyang manganese basin is formed by the enrichment of the combination between manganese and CO₃^2- in interglacial period, and the manganese in the sea basin were from the deep crust through fault zones in the glacial period.

Abstract:This paper is the result of mineral exploration engineering. [Objective] In recent years, sandstone type uranium deposits have developed rapidly in North China. The geological exploration of sandstone type uranium deposits in the Tarangaole area has made significant discoveries. Through the study of sandstone type uranium deposits in the Tarangaole area, it is helpful to better explore the distribution rules of deep sandstone type uranium deposits and the occurrence patterns of petrology and mineralogy. The stratigraphic structure of Tarangaole is similar to that of Na Linggou and Da Ying uranium deposits, but the rock characteristics of ore bearing strata and the occurrence of uranium minerals in the study area are not clear. [Methods]In this paper, through core observation, systematic sampling and detailed identification under microscope, the uranium ore in Tarangaole area was analyzed by EPMA. [Results] The results show that the sandstones in the lower member of Zhiluo Formation of Middle Jurassic are mainly feldspathic lithic sandstone and lithic arkose， With low compositional maturity and structural maturity, and have the characteristics of near provenance deposition. [Conclusions] The results of electron microprobe analysis show that the main uranium minerals are pitchblende, uranite and a small amount of ilmenite. The backscatter images show that uranium deposits are mostly distributed together with pyrite and organic matter minerals, indicating that pyrite and organic matter minerals provide reducing agents for the formation of uranium minerals.The development of dissolution and epigenetic alteration during diagenesis provides favorable conditions for uranium enrichment and precipitation. By observing thealteration phenomena and the characteristics of altered minerals in sandstone of ore bearing Tarangaole bed, it is shown that the clay minerals transform each other under certain physical and chemical conditions. The change of geochemical environment causes the mutual transformation of clay minerals and further changes the geochemical environment of ore-bearing sand bodies.

Abstract:This paper is the result of mineral exploration engineering. [Objective] Pyrite is the most common metal mineral of the Pangjiahe gold deposit, and it is also the most important gold-bearing mineral. Its typomorphic characteristics contain abundant geological information. [Methods] This paper conducts systematic analysis and research by selecting the morphological typomorphic characteristic, pyroelectric typomorphic characteristics and compositional typomorphic characteristic of pyrite, which is newly discovered in IV- 2 ore body in the eastern part of the deposit. [Results] It is found that crystal morphology of pyrite is mainly cubic and pentagonal dodecahedron, characterized by high arsenic, iron deficiency and sulfur. The average value of Fe/(S+As) is 0.860, and the ratio of Co/Ni is mainly concentrated between 1 and 10. [Conclusions] The calculation shows that the deposit is formed in a shallow depth, medium-low temperature environment, and the ore-forming fluid has obvious metamorphic properties. The vertical variation of pyroelectricity and morphology of pyrite indicates that there is still potential for deep ore prospecting, and preliminary calculations indicate that there is still an extension of 186 m downward ore at elevation of 861 m.

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