Abstract:Abstract:[Objective]The Yichang area of Hubei Province is one of the important frontier areas of shale gas exploration on the Middle Yangtze platform. Field investigation and drilling works in recent years show that the Cambrian Shuijngtuo Formation in this area is a shale gas exploration target with great potential industrial value. [Methods]Based on the latest borehole data in this area, the characteristics of high-quality shale reservoirs and the hydrocarbon accumulation patterns are identified by means of multidisciplinary methods. [Results]The shale of the Shuijngtuo Formation has high organic matter abundance, with TOC mainly distributed in the range of 0.56%~8.42%. Organic matter is dominated by type II1 and type I kerogen, and Ro equivalent value is distributed in the range of 2.4%~3.2%. Porosity and permeability values of shale reservoirs within the Shuijngtuo formation are mainly in the range of 0.5% ~ 9.1% and 0.019 ~ 0.540×10-3 μm2. Reservoir pore spaces of shales within the Shuijngtuo Formation mainly includes organic pores, inorganic pores and fractures. Occurrence of pore spaces is mainly related to the enrichment degree of organic matter, the content of clay minerals and the development degree of fractures. Natural gas is mainly attached to the shale reservoir in the form of adsorbed gas (45.21%~81.44%) and free gas (18.56%~54.79%), and the proportion of dissolved gas is relatively small. The gas bearing property of the shale reservoir is mainly related to the content of organic carbon, the proportion of brittle minerals and the degree of fracture development. The higher the proportion of organic carbon, the proportion of brittle minerals, and the degree of fracture development, the better the gas bearing property of the reservoir becomes. [Conclusions]Based on the geochemical, petrophysical and field measurement data, this study concluded that the shale gas of the Shuijingtuo Formation in Yichang area has great commercial value and is one of the ideal targets for shale gas exploration and development in southern China.

Abstract:Abstract: [Objective] Peridotite is an important mineral resource in China, which is widely used in building materials, refractory materials and fertilizer raw materials. Studying the origin, distribution and prospecting prospect of peridotite ore deposit is an effective way to solve the shortage of olivine resources in our country, and it is an important guideline for discussing the origin and prospecting direction of chromite ore deposit. [Methods] This paper summarizes the origin,distribution, mineral deposit types, development and utilization of peridotite in China by collecting and sorting out previous research data. [Results] According to the output of olivine, peridotite includes two main types of deposit: peridotite envelope type occurring in basalt and vein filling hydrothermal type occurring in peridotite. The main mineral areas of peridotite in China are Nanyang in Henan Province, Hebei Province, Jiaohe in Jilin Province and Shangnan in Shaanxi Province. Jiaohe olivine gem deposit in Jilin is the main source of olivine gem in China. The calc-magnesium-olivine deposit in Shangluo Mountain area at the border of Henan Province and Shaanxi Province has reserves of about 500 million tons with a grade of 44%. [Conclusions] The known resources of peridotite in China are not very rich, but the ore quality is good. As of 2022, China''s Ministry of Natural Resources statistics, the national reserves of 16008 million tons, the total amount of peridotite ores for fertilizer in the country is 2,492,200 tons, and the total amount of peridotite ores for refractory in the country is 17,766,100 tons. The olivine gem deposit in Jilin Jiaohe and Wanquan County of Hebei Province is an important olivine gem deposit because the olivine gem mine in Hebei Province has been closed. At the same time, the partial melting of peridotite is closely related to the enrichment of chromium, and the liquid phase immiscibility of the melt formed by partial melting of the depleted mantle leads to the formation of silicate magma and chromium-rich pulp. The study of peridotite is of great significance not only for the exploration of peridotite deposits, but also for the deposits with peridotite as the surrounding rock.

Abstract:[Methods]Plant fossils are the best materials to record terrestrial climate change in geological history, especially to the change of the paleo-CO2 concentration. Phoenicopsis (Windwardia) cf. rudinervis was identified due to the study of the morphology of the fossils collected from the Jurassic Yan ''an Formation in well Ningdong 2, Yanchi area, Ordos Basin. [Objective]In order to reconstruct the paleo‐atmospheric CO2 concentration, paleo‐temperature and water use efficiency of plants during the Middle Jurassic, leaf fossils of Phoenicopsis (Windwardia) cf. rudinervis were selected from horizon for calculating the the epidermal stomatal parameters and their isotope carbon composition of leaf cuticles. [Results]The results show that the average stomatal index (SI) of Phoenicopsis (Windwardia) cf. rudinervis is 4.25%, The paleo‐atmospheric CO2 concentration obtained by the stomatal ratio method is 1599 ppm. The paleo‐average temperature of Yanchi is about 1.2℃~31.4℃. The average value of the stable carbon isotope δ13C of plant fossils is -23.6‰, and its water use efficiency (WUE) is calculated to be 348.2 mmol/mol. [Conclusions] In general, the Middle Jurassic of Yanchi area in Ordos Basin belongs to a warm temperate - subtropical humid climate which reflected by the high CO2 concentration. Compared with previous data, we speculate that the paleo-CO2 concentration of the Middle Jurassic in northern China was significantly higher than that of the Early Jurassic, which may be related to the large-scale volcanic activities of the Yanshan Movement.

Abstract:[Objectives]The magnitude and direction of in-situ stress are important parameters for well placement, fracturing design and reservoir evaluation in hot dry rock development. It is of great significance to study reservoir stress state for hot dry rock development. [Methods] In this paper, the characteristics of current stress field in Gonghe Basin are analyzed based on regional geological structure evolution, focal mechanism solution and inversion results, statistics of joints and fissures, and in-situ stress measured data. Combined with the reservoir structure and stratigraphic lithofacies characteristics of Gonghe GR2 well, a three-dimensional model is established, and the three-dimensional in-situ stress data of well GR2 in Gonghe Basin is obtained through numerical simulation by using orthogonal anisotropic elastic constitutive relation. The regional tectonic stress field and occurrence conditions of dry hot rock resources are discussed. [Results] The results show that: ① The simulated stress distribution is consistent with the theoretical value, which meets the requirements of initial displacement accuracy, and finally predicts the distribution characteristics of in-situ stress field in the well. ② In the depth range of 500~4500 m, the relationship of three principal stresses is principal stress is σv> σH >σh, indicating that the stress structure in this region is favorable to normal fault activity. ③ The maximum horizontal principal stress direction of Gonghe Basin in Qinghai province is mainly NE direction compression deformation, which is conducive to low fluid permeability and low heat transfer of granite. ④Under the action of a unified regional stress field, the faults may be come instability near the injecting well, when the continuous injection pressure on the ground reaches or exceeds about 19.9 MPa during the water injection development of 3900~4500 m depth in the study area, leading to the occurrence of medium and small earthquakes, which should be prevented in the development and utilization of the hot dry rock. [Conclusions]This study have certain reference value for geodynamics research and the safe development and utilization of dry hot rock in Gonghe Basin.

Abstract:Abstract: The paper is the result of geothermal geology survey engineering. [Objective]The mountainous areas surrounding the capital city belong to the ecological conservation area of Beijing-Tianjin-Hebei, including the contiguous areas of extreme poverty, and are rich in hot spring resources, but the degree of exploration and development is low. It is of certain guiding significance to carry out research on the distribution pattern and development characteristics of hot springs for the exploration and development of geothermal resources in mountainous areas. [Methods]In this paper, based on the collection of information on hot springs and deep tectonics in the mountainous areas of Beijing, Tianjin and Hebei, superimposed analysis reveals the connection between hot spring distribution and deep tectonic thermal background, and explores in depth the hot spring heat source and its formation. Combined with supplementary surveys, sample collection and comprehensive research, the development characteristics of hot springs were summarized, and prospects for hot spring development and utilization in the study area were proposed according to local conditions. [Results]The results show that hot springs are mainly distributed along NE and EW deep major fractures in the form of bands or beads, 90% of the hot springs are distributed within the deep structural variation zone of the Moho surface in the study area. The temperature of hot springs has a certain negative correlation with the depth of dwelling, the depth of dwelling in the high hot spring area in the northern Yanshan being about 20km, the depth of dwelling in the relatively high hot spring area in the Yanshan-Taihang Mountains junction zone being about 22～24 km and the depth of dwelling in the low hot spring area in the southeast Yanshan being 22～26 km; the heat source of hot springs mainly comes from the mantle heat or "low-velocity-high-conductivity layer", and the upper mantle diapirs and deep large faults provide good channels for the upwelling of deep heat sources; On the regional scale, there is no direct correspondence between the hot spring outcrop temperature and the depth of circulation, and the thermal reservoir temperature of sedimentary rock reservoirs in the intermountain basin is low, with a large flow rate of hot springs, up to about 120 m3/h. The thermal reservoir temperature of metamorphic rocks is generally greater than 100℃, with a smaller flow rate. The hot spring water in the study area generally has medical development and utilization value, among which, the northern Yanshan and intermountain basins, have a better potential for space heating, and areas such as Qijia-Maojingba can be further developed in the direction of thermol-electric integration. [Conclusions]The distribution and development characteristics of hot springs in the mountains area around the capital city are influenced by the deep tectonic and regional geological structure. The northern Yanshan Mountains and intermountain basins have good development and utilization prospects.

Abstract:Abstract:This paper is the result of land quality geochemical survey engineering. [Objective] Metal elements mainly enter the human body through the food chain, thus affecting health. Research on the geochemical characterization of heavy metal elements in the soil-rice system is significant for the scientific management of arable land, the guarantee of food security and the implementation of the strategy of a healthy China.[Methods] A total of 129 sets of rice seeds and root soil samples were systematically collected, analyzed by chemical analysis to obtain geochemical data such as As, Cd, Hg, Pb, Cr, pH, and soil Cd morphology, thus using the human health risk model to assess the health risk in the study area. [Results] (1) The average soil Cd content in the study area was 0.49 mg/kg, which was significantly higher than the background value of Jiangxi surface soil.There were 80 soil samplesCd content higher than the risk screening value, accounting for 62%.There were 57 rice seeds with excessive Cd content, the rate of exceeding the standard was 44%.(2) The results of the pollution evaluation of soil Cd and safety evaluation of rice seeds Cd in the study area were poorly correlated.Soil pH was the major influencing factor, with soil alkalinity increasing, soil Cd content increased by 2.3 times, but rice seeds Cd content decreased by 4.5 times.(3) The three fugitive forms of water-soluble, exchangeable and residual Cd in the soil had a significant effect on the Cd content of rice seeds, and the bio-efficacy of Cd was enhanced in a strongly acidic soil environment.(4) Children in the study area have greater health risks than adults, with non-carcinogenic and carcinogenic risk factors dominated by the heavy metal Cd.[Conclusions] The correlation between soil Cd and rice seeds Cd content in the study area is relatively poor, and there are some limitations of misjudgment and omission according to the current norms; the health risk evaluation results revealed that there is a human health risk caused by rice Cd intake in the study area.

Abstract:[Objective] The slope deformation is common in the mountainous areas, which significantly promotes landslide development and increases landslide risk. So, it is the important factor for the regional landslide assessment. [Methods] By reviewing literatures, the research status of regional landslide assessment integrating slope deformation characteristics were summarized. [Results] The relevant theoretical models and technical methods are not mature and are still in the stage of preliminary research. The temporal resolution of regional slope deformation should be further improved, and key characteristics of the long time series slope deformation should be captured, and the spatio-temporal distribution of regional slope deformation should be deeply analyzed. A preliminary regional landslide assessment system integrating slope deformation was constructed, including process steps, technical methods and factor indicators. The main technical methods include the qualitative judgment based on expert experience, weighted layer overlay based on expert experience and correction matrix, slope deformation as a factor index of regional landslide assessment, slope deformation as a landslide sample of regional landslide assessment. The slope deformation factor can be further divided into slope deformation type, intensity, distribution position and time change. [Conclusions] It is necessary to combine new technologies such as machine learning and artificial intelligence to propose or optimize the new quantitative regional landslide assessment models that integrate the slope deformation characteristics to improve regional landslide assessment accuracy. It is expected to promote the study on regional landslide assessment integrating slope deformation, and support the early landslide prevention in the complex mountainous areas.

Abstract:Abstract: This paper is the result of geological survey engineering. [Objective] A total of 775 soil samples were collected in Longshan County for the purpose of analyzing the content characteristics of soil heavy metals, including As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. Additionally, an evaluation of the health risks caused by soil heavy metals was conducted. [Methods] To assess the level of soil heavy metal pollution, the geo-accumulation index was utilized. The source of soil heavy metals was identified through correlation analysis and principal component analysis. Furthermore, a health risk model was employed to assess the potential risks imposed by soil heavy metals on human health. [Results]The results of the analysis revealed that the average concentration of Cd in the soil of Longshan County was significantly higher than the background value observed in the soil of Hunan Province. This suggests that there is a certain degree of Cd enrichment in the soils of Longshan County. Moreover, the coefficients of variation for Hg, As, and Cd were greater than 0.5, and the coefficient of variation for Hg exceeded 1, indicating that these heavy metals may be influenced by human activities. The presence of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn contamination was observed in the soils of Longshan County. Notably, Cd pollution was widespread, and some areas exhibited severe levels of Hg contamination. The sources of soil heavy metals in Longshan County can be categorized into three groups: Cr, Cu, and Ni primarily originate from the soil parent materials, while As, Cd, Pb, and Zn are predominantly influenced by lead-zinc mining and smelting activities. The source of Cd also has some association with the soil parent materials. Furthermore, Hg is mainly derived from the combustion of fossil fuels. The health risks caused by soil heavy metals were found to be higher for children compared to adults. Additionally, special attention should be given to the health risks caused by soil heavy metals in Liye Town, Miaoertan Town, and Luota Town of Longshan County. Furthermore, non-carcinogenic risks are primarily attributed to As and Cr, whereas carcinogenic risks are primarily linked to Cr and Ni. Oral ingestion was identified as the main exposure route contributing to health risks. [Conclusions] There was a variable degree of heavy metal pollution in the soil of Longshan County, and As, Cr, Ni were the main contributing factors to health risks.

Abstract:[Objective] Dingbei area is rich in tight gas resources of Upper Paleozoic and has great exploration potential. However, faults are widely developed in this area, and the characteristics of geostress field near the fault zone are unknown, which seriously restricts oil and gas exploration and development in this area. [Methods] Therefore, this paper conducts a detailed analysis of the characteristics of the Upper Paleozoic geostress field in the study area based on differential strain experiment, acoustic emission experiment, logging interpretation of geostress size, wave velocity anisotropy experiment, paleomagnetism experiment, imaging logging and dipole acoustic logging data interpretation of geostress direction, numerical simulation and other methods, in order to find out the distribution characteristics and disturbance mechanism of the geostress field in Dingbei area. [Results] The research shows that the three-dimensional stress of Upper Paleozoic in Dingbei area has the characteristics of vertical principal stress > maximum principal stress > minimum principal stress, and the regional geostress field is mainly controlled by the fault zone, and the stress disturbance degree is related to the fault location, fault scale, fault genesis and other factors, among which the three-dimensional stress in the karst fault zone is relatively lowest. The direction of regional principal stress field is N35°E ~ N45°E. The direction of reservoir geostress is mainly controlled by the direction of regional principal stress field and fault zone, and the range and degree of geostress disturbance caused by different types of fault zones are different, among which the range of geostress disturbance is mainly affected by fault strike and fault length. [Conclusions] Based on the research on the characteristics of geostress field, this paper clarifies the distribution characteristics and disturbance law of geostress size and direction in Dingbei area, discusses the disturbance mechanism of different genetic fault zones on geostress size, and establishes a prediction model for the disturbance width of geostress direction in the research area, which has important reference value for subsequent well pattern deployment and fracturing reconstruction.

Abstract:[Objective] The leakage of leachate from a landfill can cause severe groundwater contaminations. Characterization the spatial distribution of the landfill-derived contamination plume is crucial for site remediation and pollution investigation. [Methods] In this paper, a typical case of groundwater pollution investigation at a landfill in Hubei is combined with the implementation of a six-layer groundwater multilevel sampling well (-6 m、-8 m、-10 m、-12 m、-16 m、-20 m), and 14 sets of groundwater chemical samples as well as other hydrogeological survey data to reveal the hydrogeochemical spatial distribution of the contaminated groundwater. [Results] The results indicate that the concentrations of most ions in groundwater such as TDS, COD (Mn), Mg2+, HCO3- and Cl- decrease linearly with increasing vertical depth, thus indicating that surface rainfall infiltration and anthropogenic pollution are the controlling influences on the shallow groundwater. The concentration of NH4+, NO3-, NO2-, Mn, Ni and other ions increases linearly with increasing vertical depth, reflecting groundwater chemical field under the control of natural geological condition and water-rock interaction. In addition, the correlation coefficient matrix analysis characterises the stratified distribution of groundwater chemical components, the correlation coefficient between the groundwater sample from the U-tube groundwater multilevel sampling well and other conventional shallow boreholes decreases from 0.984 to 0.566.[Conclusions]The conclusion indicates that the novel groundwater multilevel sampling technology has the ability, to characterize the hydrogeochemical spatial distribution of groundwater along the vertical depth of the geological layers, to differentiate and reveal the impacts of natural geological factors and human-made pollution, thus to identify the spatial distribution of groundwater plumes. In a word, the groundwater multilevel sampling technology could provide quantities’ data and accurate guidance for site-scale groundwater pollution remediation and risk management.