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  • Regional Geology
    ZHAO Ligang, WANG Wenlong, GAO Xuesheng, WANG Shuqing, XU Yawen, HU Xiaojia
    North China Geology. 2024, 47(2): 1-16.

    This paper is the result of rock geochemistry. [Objective]The Baoerhantu Group is mainly distributed in the northern region of Damao Banner and is a key area for studying the early Paleozoic tectonic evolution of the ancient Asian Ocean. [Methods]This article conducts petrological, geochemical, isotopic geochemical and chronological studies on the basic volcanic rocks in the Baoerhan map of Damaoqi area, in order to explore their formation age and diagenesis. [Results]The LA-ICP-MS zircon U-Pb diagenetic age of the gneiss like plagioclase amphibolite in the Baoerhantu group was 495 ± 2.0 Ma, while metamorphic zircon ages of 242.3 ± 1.1 Ma and 249 ± 3 Ma were obtained in the amphibolite greenstone and plagioclase amphibolite, respectively. [Conclusions]The geochemical characteristics of the gneiss like plagioclase amphibolite are characterized by enrichment of large ion lithophilic elements such as Rb and Th, and depletion of high field strength elements such as Nb, Ta, P, and Ti, indicating that the Baoerhantu Group had volcanic eruptions during the Cambrian (ε3), and its formation is related to the subduction of the ancient Asian Ocean from north to south. The hornblende epidote and plagioclase hornblende exhibit MORB type geochemical characteristics, and the captured zircons contain both the ancient recycled continental crust material of the North China Plate and the newly formed basic lower crust material of the Paleozoic era, which can limit the closure of the ancient Asian Ocean to be earlier than 249 Ma.

    Highlights: Discovery of zircons of Early Middle Triassic metamorphic origin in the Baoerhantu Group, providing new ideas for limiting the closure of the ancient Asian Ocean.

  • Hydrogeology and Envieronmental Geological Survey
    YAN Jiaxian , ZHANG Sen , ZONG Zhenhai , QIN Dongshi , SHEN Jian , LI Hu , YIN Xiaoxiao
    North China Geology. 2024, 47(2): 54-61.
    This paper is the result of geothermal geology. Geothermal is a clean energy source, and local concentrated extraction of geothermal fluid will cause a pressure depression cones. [Objective] Due to the long history of geothermal development, multiple large-scale pressure depression cones have been formed in the Tianjin area. Since 2018, the water level in the center of the cones began to rise rapidly and the thermal reservoir pressure began to recover after the gradual reduction of mining output. However, there are few studies on the correlation between the water level rise and the change of mining output, and what changes will happen to the cone shape, and the understanding of the evolution law is not clear enough. [Methods] This article takes the dynamic changes of water level in the Guantao Formation of the Neogene in Tianjin as an example, analyzes the correlation between extraction and reinjection volume and water level, studies the dynamic evolution law of water level in the cone area, analyzes the cause for pressure recovery, and provides reasonable suggestions for evaluating geothermal recoverable amount in the depression cones. [Results] The study suggests that the continuous "insufficient inflow" of thermal reservoir water is the fundamental cause for the formation of a pressure depression cone, while the combined effect of group wells pumping leads to synchronous fluctuations in thermal reservoir pressure, a sharp decrease in consumption, and the flattening effect of the cone causing the water level in the central area of the cone to rise.[Conclusions] Geothermal evaluation and management should be based on the real-time dynamics of thermal reservoir pressure in the cone area, and reasonable control of consumption and maintenance of water balance are effective ways for the sustainable utilization of geothermal resources.
  • Regional Geology
    HE Peng , GUO Shuo , SU Hang
    North China Geology. 2024, 47(2): 16-27.
    This paper is the result of the research on the geochronology, geochemistry and tectonic setting of volcanic rocks.[Objective] The volcanic rocks of Baiyingaolao Formation in the southern section of Da Hinggan Mountains are the host rocks of the Changtuxili Ag-Pb-Zn-Mn polymetallic deposit. Conducting research on volcanic rock chronology, geochemistry, and tectonic environment is of great significance for identifying the geological background of the deposit and guiding the next exploration of the deposit. [Methods] This study conducted petrological, zircon U-Pb geochronological, and geochemical studies on the volcanic rocks of the Baiyingaolao Formation to clarify their formation age, petrogenesis, and tectonic evolution environment. [Results] The main body of the Baiyingaolao Formation in this area is a set of rhyolite and rhyolite volcanic clastic rocks. The zircon U-Pb dating result is (133.85±0.81 Ma), which was formed in the Early Cretaceous. The main elements have the characteristics of high silicon(SiO2=71.00%~74.43%), rich alkali (ALK=7.10~8.78), rich potassium, high FeOT / MgO ratio(7.51~22.54), poor magnesium(MgO=0.11%~0.45%), and poor calcium(Ca=0.88%~1.83%), belonging to the high potassium calcium alkaline series rocks. All samples have a similar REE pattern with medium total REE contents (ΣREE=156.66~211.81), significant fractionation of LREE and HREE ((La / Yb)N=9.39~16.91), attributed to the enrichment type with strong negative Eu anomalies (δEu=0.38~0.59). Similar REE distribution patterns imply that the volcanic rocks came from the same magma source. The trace element geochemistry shows evident enrichment of LILE Rb, K, Th and U, deficit of HFSE Nb, Ta, Ti, P.[Conclusions] Based on regional geological data and the research results of this article, it is believed that the volcanic magma of the Baiyingaolao Formation in the study area originated from partial melting of crustal rocks and was generated in the post orogenic extensional tectonic background. Its formation is mainly related to the lithospheric extension after the closure of the Mongol-Okhotsk Ocean, and the subduction of the ancient Pacific Plate also has a certain influence on it.
  • Hydrogeology and Envieronmental Geological Survey
    ZHAI Bonan , ZHANG Siyuan , ZHANG Fuchen , YUAN Shuai , HAO Yi , MAO Chen
    North China Geology. 2024, 47(2): 38.
    This paper is the result of geochemistry geology.
    [Objective] Irrigation water is an important input route for elements in soil and crops, in order to identify the geochemical 
    characteristics of irrigation water and major crops in Dashetai area of Inner Mongolia, geochemical evaluation of irrigation water and crop quality was carried out.[Methods] A total of 30 irrigation water samples, 28 corn samples and 13 pepper samples were collected in Dashetai area during September to October of 2021. [Results] Geochemical tests were carried out, and the test results showed that the chemical type of irrigation water in the wells in the survey area was HCO3-Na · K ions are mainly derived from silicate rocks, Ca2+ and Mg2+ ions are mainly derived from the dissolution of carbonate and sulfate minerals such as calcite, dolomite and gypsum, and silicate minerals are also one of the main sources, and strong ion exchange occurs.[Conclusions] The irrigation water is alkaline, the main heavy metal elements and compounds are within the specified limits, which meet the irrigation water quality standards, combined with the evaluation indicators such as SAR, SC, PI and RSC, it is considered that the irrigation water quality in the area is better. The heavy metal content in chili pepper and corn is below the limit value specified in the standard lmit, which is at a safe level. On the whole, the Dashetai area is an excellent agricultural cultivation area.
  • Hydrogeology and Envieronmental Geological Survey
    NING Hang , LIU Futian , WANG Guoing , ZHANG Jing , ZHANG Zhuo , CHEN Sheming
    North China Geology. 2024, 47(2): 62-72.
    This paper is the result of the evaluation of groundwater resources and analysis of geological environment problems.[Objective] In order to improve the understanding of hydrogeology and groundwater resources in Inner Mongolia inland river basin,improve the utilization efficiency of groundwater resources and reduce the geological environment problems. [Methods]Taking In‐ner Mongolia Inland River Basin as the main work area, this paper identified the drainage characteristics and hydrogeological condi‐ tions of the basin, collected and sorted out the meteorological and groundwater development and utilization data of the basin in the past 20 years, updated the hydrogeological parameters related to groundwater resource evaluation, and summarized and analyzed the drainage items of groundwater resources in the basin. The drainage method and recharge method were used to evaluate groundwater resources in hilly and plain areas. At the same time, the characteristics of groundwater dynamic change in the basin are discussed comprehensively, and the ecological and geological environment problems related to groundwater such as lake shrinking and land de‐sertification are discussed. [Results] It is calculated that the total groundwater resources in the inland river basin are 3.794 billion m3. The shallow groundwater level in the upper Bashang area generally experiences a general trend of first rising and then decreas‐ing, and the groundwater level generally presents a cyclical trend during the year. Affected by the groundwater level, the lakes in thebasin shrink seriously, the sandy desertification area decreases, and the saline-alkali desertification gradually increases.[Conclusions]This study provides basic data and scientific basis for sustainable development and utilization of water resources and ecological envi‐ronment protection in this area.
  • Hydrogeology and Envieronmental Geological Survey
    XU Danhong, LIU Jihong, ZHANG Surong, LIU Hongwei, BAI Yaonan, LI Zhuang
    North China Geology. 2024, 47(2): 28-37.
    This paper is the result of geochemistry. [Objective] In recent years, selenium enrichment industry has developed rapidly, but because there is no significant positive correlation between selenium content in soil and selenium content in crop seeds, the planting regionalization of selenium-enriched agricultural products based on soil selenium content has certain uncertainties. Therefore, how to establish the selenium-rich model of agricultural products to predict the production area of selenium-rich agricultural products and make reasonable planning is an urgent scientific problem. [Methods] The crops and soils were collected from Zhangbei county of Hebei province. And pH, organic carbon, silica, aluminum trioxide, calcium oxide, magnesium oxide, ferric oxide, potassium oxide, sodium oxide, selenium, arsenic, mercury, cadmium, lead, copper, zinc, chromium, and nickel were measured. The influencing factors of selenium uptake in crops were studied, and the prediction model of crop selenium content based on neural network was established, and the yield area of seleniumrich crops was predicted, base on the results of measurement and the data of 1/250000 multiple geochemistry collected. [Results] There were only 2.31 percent of topsoil sites reached the standard of selenium-enriched, and they mainly distributed in the northern area of Sanhao Town. There are 6 naked oats which meet the standard of selenium-enriched, and the selenium-enriched rate is 16.67 percent. While there are 7 flaxseeds which meet the standard of selenium-enriched, and the selenium-enriched rate is 21.86 percent. There was a negative relationship between crops' bioconcentration factor for selenium with organic carbon, ferric oxide and aluminum trioxide, a positive relationship with pH in soil. The prediction model of selenium content in flax and naked oat seed was established by machine learning, and the results were reliable. The potential production areas of flax and naked oats were mainly distributed in Zhangbei, Xiaoertai, Tailugou, Youlouou and Haojiaying Town, etc, and the output areas were 2 486 km2 and 2 406 km2, respectively.[Conclusions] The area of selenium-rich crop producing area defined by the prediction model is much larger than the selenium-rich soil area, which is of great significance for the development of selenium-rich agriculture in Zhangbei County.
  • WANG Jiasong, YUAN Guiqin, ZHANG Guoli, LIU Jihong, WANG Liqiang, ZHENG Zhikang
    North China Geology. 2024, 47(2): 80-88.
    This paper is the result of the research on the standard system of geophysical exploration technology [Objective] As an essential technical guarantee for the development of the geological industry, the tendency of refinement and integration in exploration technical standards objectively necessitates the acceleration of digitization of existing standards to meet various demands such as rapid retrieval, analysis, comparison, splitting and reconstruction of standard technical contents.[Methods] Considering that code of practice is the standard type with the largest proportion and similar structure in exploration technical standard system, the code of practice for magnetotelluric sounding (DZ/T 0173-2022) is taken as the research object. Refer to the tagging framwork of national standard, DZ/T 0173-2022 was structured based on extensible markup language XML. [Results] The corresponding relationship between the composition elements and the structural framework of the code of practice in exploration technical filed is established, and the structural description of basic information, auxiliary information, terminology information and technical contents of exploration technical standards was realized based on XML. It is pointed out that the structural framework suffers from deficiencies such as incomplete elements, limited descriptive dimensions and relatively coarse granularity of structured modules. [Conclusions] The research on digitization of exploration technical standards should be strengthened in the aspects of standard structural metamodel, tag set, content template and style sheet of different functional types, so as to realize the standard content structure of all elements, multi-dimension and fine granularity, laying a preliminary foundation for machine readable and transferable exploration technical standards.
  • Hydrogeology and Envieronmental Geological Survey
    HE Shuyan , SONG Mian , GONG Lei , LV Lin , MENG Shunxiang
    North China Geology. 2024, 47(2): 73-79.
    This paper is about the research on the Karst Water system. [Objective] Karst water is the main water source of cities and towns in northern China. In this paper, the hydrogeological characteristics of the karst water system in Shenxian Mountain in Fuping are studied.The research results can provide an important reference for the rational development and utilization of karst water in Fuping. [Methods] This paper mainly takes the karst water system of Shenxian Mountain in Fuping as the research object, and systematically summarizes the hydrogeological characteristics of the karst water system in the study area by studying the geological background of karst formation, karst development characteristics,aquifer structure, groundwater circulation, and karst water chemical characteristics. [Results] The groundwater system of karst of Shenxian Mountain in Fuping is a relatively independent karst hydrologic system. Karst hydrologic system boundary consists of carbonate rock and metamorphic rock boundary ,the water separation boundary formed by water resistance fault structure and the surface underground watershed boundary. The karst water system is divided into dolomite karst fissure aquifer of Jixian system and Changcheng system and the limestone karst fissure aquifer of Ordovician-Cambrian system. The atmospheric precipitation in Shenxian Mountain area of Fuping is the main source of groundwater recharge. The atmospheric precipitation infiltrates along the cracks to recharge the groundwater. The karst groundwater in Fuping Shenxian Mountain is excreted in the form of Jinlongdong spring (underground river), with a water volume of 5382-75466 m3/d.The strontium content in the spring water is 0.58-1.28 mg/l,which reaches the limit index of ' drinking natural mineral water ' (GB 8537-2018). [Conclusions] Karst develops in ShenxianMountain area of Fuping, forming a relatively independent karst water system, and groundwater circulates in the system. It is appropriate to build underground water retaining structures near the Jinlongdong underground river to form underground karst reservoirs, which has considerable development and utilization value.
  • ZHANG Yibin , LIU Hua , XU Siyu , Li Ying , XU Yuwei , SONG Jinhong
    North China Geology. 2024, 47(2): 89-96.
    This paper is the result of the research on geological information techology. [Objective] In order to comprehensively improve the geological environment information service ability of Jilin Province and solve many problems such as scattered geological environment data storage, lack of data sharing service mechanism and weak comprehensive analysis ability, Jilin Province geological environment information data sharing and service platform was developed by adopting the concept of "big integration, big integration and big integration". [Methods] The platform takes Service-Oriented Architecture (SOA) as the overall framework. Net, Geographic Information System (GIS), Virtual Reality (VR), database and other technology support. Based on hash grid improvement of ellipsoid quadtree spatial index and slice database construction technology, SOA and WCF geological environment big data sharing and service technology, C/S and B/S mode information system integration and other key technologies. [Results] The platform highly integrates geological environment survey, monitoring and comprehensive evaluation data, standardizes the whole process of geological environment data from production, collection, integration, management, update, sharing to application, and adopts the personalized functions of work system, service system and science popularization system to enhance the professionalism and universality of geological environment data services. And based on VR technology and geological environment cross-research to improve the breadth and depth of geological environment data application.[Conclusions] The platform has greatly improved the scientific and technological innovation ability and modernization level of the transformation of geological environment achievements, and is of great significance for accurately serving geological environment investigation, monitoring, protection and geological disaster prevention.
  • HE Bolin , LIANG Siwei
    North China Geology. 2024, 47(2): 96-104.
    This paper is the result of engineering geophysical exploration. [Objective] The complex resistivity inversion parameters are four Cole-Cole model parameters, which directly increases the multisolution of complex resistivity inversion. Moreover, the sensitivity of real and imaginary parts of complex resistivity to different Cole-Cole models is different, so the ability of complex resistivity inversion is required. [Methods] In this paper, the regularization idea is introduced into the weighted inversion of the real and imaginary parts of complex resistivity, and four Cole-Cole model parameters are inverted in four steps, and four different weighting coefficients are designed to weight the objective functions of the real and imaginary parts in the inversion of different Cole-Cole parameters, so as to control the proportion of the real and imaginary parts in the inversion. When inverting the same parameter, the inversion results of different initial models are compared, and the influence of the initial models on the inversion results is analyzed. [Results] Model test results show that this algorithm can not only improve the inversion effect of Cole-Cole model parameters, but also reduce the dependence of inversion results on the weighting coefficient and some parameters on the initial model. [Conclusions] The algorithm used in this study has effectively improved the accuracy of the inversion process for the Cole-Cole model parameters.
  • Hydrogeology and Envieronmental Geological Survey
    WANG Yudong , LIU Juan , XIE Jinhang , LI Zhangjie , ZHANG Xiaoliang , ZHANG Jie , LIANG Xingxing
    North China Geology. 2024, 47(2): 45-53.
    This paper is the research on the geological disasters. [Objective] Located in the semi-mountainous region of the Yungui Plateau, Huize County is frequently affected by geological disasters, particularly landslides. This study focused on landslide hazards, with a coupled model being employed for vulnerability assessments, aiming to develop an evaluation model tailored to the unique geographical and environmental characteristics of the semi-mountainous area of the Yungui Plateau.[Methods]Twelve evaluation factors, including topography, slope, and aspect, were carefully selected. The probability of landslide occurrence was calculated using the Coefficient of Determination (CF) and Logistic coupling model. The results were graded using the GIS-based Natural Breaks method. The model underwent rigorous validation through rationality and sensitivity tests.[Results](1) Elevation, distance to faults, distance to roads, and slope were identified as significant influencers on landslide susceptibility in Huize County. (2) The areas categorized as stable, low, moderate, and high susceptibility cover 46.25 km2 (0.61%), 3 095.41 km2 (52.77%), 1 296.64 km2 (21.94%), and 1 446.53 km2 (21.94%), respectively. (3) The Coefficient of Determination (CF) and Logistic coupling model demonstrated high rationality, with an AUC value of 0.927.[Conclusions](1) Moderate to high susceptibility landslide areas are concentrated in the southwest and northeast regions of Huize County, while low susceptibility and stable areas are prevalent in the northwest, central, and southern regions. (2) The application of the CF-Logistic coupling model for landslide vulnerability assessment exhibits superior rationality and accuracy.
  • YU Yang, WU Lei, WANG Na, WU Liangying
    North China Geology. 2024, 47(2): 105-110.
    This paper is the result of ICP-MS. [Objective] Rare earth elements play an important role in geochemistry, and their additive significance is also very prominent,which can be called geochemical indicators. The content of rare earth elements in rock samples was determined by ICP-MS with open acid solution - inductively, which is a common method. In order to improve the accuracy of detection of rare earth elements in rocks, the uncertainty of measurement is analyzed and evaluated from each component in the experiment.[Methods] The layer-bylayer analysis and final evaluation are established based on the source,which is the content of rare earth elements in rock samples was determined by ICP-MS with open acid solution inductively.[Results]The results showed that the combined relative standard un‐certainties ranged from 0.004 9 to 0.009 1. [Conclusions]The uncertainty of this method mainly comes from the standard solution of the sample, and the contribution value of the standard curve fitting is the largest, which is consistent with the actual test situation in the laboratory.
  • TENG Xuejian , WANG Shuqing, HAN Xue, WANG Xingwen, ZHANG Hao, LI Jihong, KANG Jianli
    North China Geology. 2024, 47(4): 1-11.

    This paper is the study on the ore-forming laws and prospecting predictions of chromite deposits in the Hegenshan area, Inner Mongolia. [Objective] Summarize the geological, geophysical, and geochemical characteristics of chromite deposits in the Hegenshan area of Inner Mongolia, summarize the regional ore-forming elements and prospecting indicators, and conduct research on prospecting prediction. [Methods] In the Hegenshan area of Inner Mongolia, regional gravity, magnetic methods, and physical property measurements were carried out. [Results] The results of regional gravity and aeromagnetic surveys show good consistency between high-value anomalies and ultrabasic rocks and major faults, thus identifying 34 areas with local gravity anomalies and inferring 5 faults. [Conclusions] Based on the comprehensive analysis of regional geology, geophysics, geochemistry, and other ore-forming elements and prospecting indicators, summarize the ore-forming laws and delineate 9 prospecting areas.

    Highlights: Summarized the geological characteristics of chromite deposits in the Hegenshan area of Inner Mongolia, identified 34 areas with local gravity anomalies and identified 5 faults, and delineated 9 prospective mining areas.

  • Hydrogeology and Envieronmental Geological Survey
    ZHANG Sen, SUN Shiyu, RUAN Chuanxia, ZHAO Yanting, ZHAO Kan,
    North China Geology. 2024, 47(4): 71-79.

    This paper is the results of geothermal resources exploration, utilization and management. 

    [Objective] Tianjin's geothermal resource endowment has outstanding advantages, and it is in a leading position in geothermal exploration, development, protection and management in China. However, under the background of the construction of ecological civilization, the security of energy resources and the realization of the goal of " double carbon, " the utilization and management of geothermal resources are still deficiency, which needs further research and discussion. [Methods] Based on the history and achievements of the utilization of geothermal resources in Tianjin, this paper discusses the current situation and existing problems of the utilization of geothermal resources, clarifies the challenges faced by geothermal management, and puts forward specific countermeasures and methods to scientifically guide the sustainable utilization. [Results] In the future, the control degree of geothermal exploration in Tianjin should be improved, and the geothermal resources of 4 000~6 000 m should be found out to ensure the supply of resources; Key technologies such as prevention and control of sandstone pore-type reinjection attenuation, reservoir reconstruction and injection of exogenous water should be strengthened to improve resource carrying capacity; It is necessary to promote multi-energy combination, grid-connected interconnection, reduce tail water temperature, improve heat supply efficiency and increase heat supply capacity; Strengthen the unity, integrity and guidance of geothermal resource management, and create a policy environment conducive to the development and utilization of geothermal resources. [Conclusions] Tianjin has a long history of geothermal exploration, and the method is perfect. Geothermal development and protection are equally important, and the management system is increasingly standardized, which has played a leading role in the national geothermal exploration. In the future, we should improve the degree of exploration and tap the deep geothermal resources; Break through the technical difficulties of sandstone reservoir reinjection attenuation, reasonably set the layout and development mode of geothermal resources utilization. Improve the life cycle management mechanism of geothermal wells, innovate the management mode of geothermal resources, and promote the healthy and orderly development of geothermal industry.

    Highlights: The history and achievements of the exploration , utilization of geothermal resources in Tianjin are discussed; The promotion effect of standardized management on the geothermal industry is studied for the first time; and the shortcomings and challenges at the present stage are clarified. The measures for sustainable development and utilization of geothermal resources are put forward from multiple perspectives, which provide a guarantee for the healthy and orderly development of geothermal industry in Tianjin.

  • Hydrogeology and Envieronmental Geological Survey
    WANG Yanyan , LIU Bin , HAN Jian, REN Junru, CHENG Tenghui
    North China Geology. 2024, 47(4): 47-56.

    This paper is the result of ecological environment. 

    [Objective] Ecological environment is the foundation for the survival and development of human beings. Remote sensing technology is used to evaluate and analyze the quality and status of the ecological environment in Chengde City provides scientific basis and technical support for the protection and governance of the ecological environment in Chengde City. [Methods] This study is based on Landsat series remote sensing images, and uses ENVI software to calculate four indicators reflecting the ecological environment: greenness, wetness, dryness, and heat. In addition, the principal component analysis method is used to construct a remote sensing ecological index model to evaluate the ecological environment quality of Chengde City. [Results] The remote sensing ecological index model was constructed by using four indicators calculated from remote sensing images of Chengde City in 2013, 2016, 2019, and 2022, and further analyzed, showing that: (1) The first principal component index in the principal component analysis was used to construct the RSEI model. NDVI (representing greenness) and WET (representing wetness) had a positive effect on the ecological environment quality, while NDBSI (representing dryness) and LST (representing heat) had a negative effect on the ecological environment quality. (2) From 2013 to 2022, the average RSEI value of Chengde City increased from 0.625 to 0.640, and the ecological environment quality showed an overall upward trend, and the ecological environment was basically improved. (3) From 2013 to 2022, the area of ecological environment deterioration in Chengde city is 2 405.562 3 km2 , accounting for about 6.07% of the total area; The unchanged area is 28 769.067 km2 , accounting for 75.54% of the total area. The improved area is 8 483.1885 km2 , accounting for 21.39% of the total area. [Conclusions] From 2013 to 2022, the overall ecological environment quality of Chengde City has shown a significant initial improvement trend. This study can provide a reference basis for regional environmental protection work in Chengde City. 

    Highlights: Based on remote sensing technology, RSEI was used to conduct a time series analysis of the ecological environment quality in Chengde City from 2013 to 2022. By comparing the RSEI values of different years, the dynamic changes in the ecological environment were revealed. Combined with rainfall and temperature factors, the reasons for the changes in the evaluation results were analyzed, and regional environmental protection measures were proposed. This helps Chengde City understand the long-term changes in the ecological environment and provides a scientific basis for formulating long-term ecological protection policies.

  • Regional Geology
    CHEN Kang, JING Yongkang, WANG Yuanwei , ZHANG Long , DENG Nan , WU Junwei , ZHANG Yi , LI Fawang , LIU Peiwen
    North China Geology. 2024, 47(4): 25-36.

    This paper is the result of research on the lithospheric mantle.

    [Objective] In terms of petrological and geochemical studies on a large number of mantle xenoliths, melt-peridotite reactions always occur in subcontinental lithospheric mantles, especially in the North China Craton (NCC). Based on the mineral metasomatic characteristics of mantle xenoliths and the related element geochemical signatures, the reaction between silicate melt and peridotite is the main type of melt-rock reaction within the NCC lithosphere mantle. However, the direct evidence of experimental petrography about the mechanism is insufficient. [Methods] In this contribution, natural olivine of harzburgite from Hebi, Henan province, and tonalite from Sandouping, Huangling, Hubei province were collected as starting material. The Si-rich melt-olivine reaction experiments were performed at conditions of 1 200~1 400 °C, 1.0~1.5 GPa, on LC25-0300/50 piston-cylinder apparatus equipped at Key Laboratory of High-temperature and High-pressure Study of the Earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, which explored the reaction mechanism and kinetics of the melt-peridotite reaction. [Results] The main crystallized phase under experimental conditions is orthopyroxene, its En content ranges from 73 to 100 discriminated into enstatite. After reactions, the MgO content of reacted melts increased and linearly correlated with the temperature, while the contents of SiO2, Al2O3 and K2O decreased linearly with the increase in temperature. As the temperature increased, more forsterite was dissolved in the melts, and with more orthopyroxene generated, the SiO2, Al2O3 and K2O of melts decreased which changed the composition of the melts. Under the pressure of 1.0GPa, the temperature rises from 1 250°C to 1 350°C, the SiO2, Al2O3, and K2O in the residual melt decrease from 66.20%, 17.24% and 1.40% to 61.91%, 16.02%, and 1.28% respectively, however MgO in the residual melt increases from 3.93% to 8.26%. Under the pressure of 1.5 GPa, the temperature rises from 1 250°C to 1 400°C, the SiO2, Al2O3 and K2O in the residual melt decrease from 65.79%, 17.64% and 1.36% to 61.74%, 15.78%, and 1.23% respectively, however MgO in the residual melt increases from 3.11% to 7.07%. [Conclusions] The pressure has a much less influence on the chemical composition change or residual melts than the temperature. In all reactions between Si-rich melt and olivine, orthopyroxene was newly formed the experimental results also explain the composition of the peridotite in NCC and the phenomenon of the orthopyroxene veins in the peridotite, which can transform the lithosphere mantle from refractory into fertile.

    Highlights: Based on High-pressure and temperature experiments, it confirmed that the orthopyroxene veins in the peridotite are the reaction results of the Si-rich melt and olivine reaction , and provided experimental petrological evidence for the lithospheric mantle transforming from“refractory”into“fertile”.

  • Li Dong, Zhu Jianlin, Lei Lian, Zan Fang, Zhuang Renwu, Zhang Heng
    North China Geology. 2024, 47(4): 12-24.

    This paper is the research of uranium deposits prospecting direction. 

    [Objective] The intermittent period of the Huanghu Ridge volcanic activity in Ganhuai belt, Jiangxi Province, China, produced a set of uranium-rich volcanic lava that is disposed in a layered manner within the Maqian Basin. The volcanic lava directly controls the spatial distribution of uranium ore bodies. Therefore, the study of the characteristics of uranium-rich volcanic lava is of great significance for analyzing the volcanic activity of this period, judging the source of mineralization, and indicating the direction of uranium exploration in the basin. [Methods] Based on the petrographic characteristics of the third section of the Yuhu Volcanic Group in the Zhujia Mine area of the Maqian Basin, this paper analyzes and tests the chemical element contents of the uranium-rich volcanic lava, the altered rocks, and the uranium ore stones. [Results] By summarizing the changes of chemical elements in the rocks and comparing and analyzing the characteristics of Andesite in adjacent areas, it is concluded that uranium-rich volcanic lava is Andesitic breccia lava and Andesite, which is rich in alkali, iron and titanium, and rich in light rare earth elements and large ionic lithophile elements (Rb, Ba, K). With the increase of uranium content in the rocks, the content of heavy rare earth elements in the ore of the Andesite series of potassium basalt lavas characterized by the loss of high field strength elements (Nb, Ta, Ti) continues to increase. It is concluded that the uranium-rich volcanic lava is formed by the volcanic eruption caused by the coupling of volcanic magma and deep uranium-bearing hydrothermal at the same period, and there is continuous uranium-bearing hydrothermal transformation in the later period. [Conclusions] Based on the characteristics of uranium-rich volcanic rocks, the search for concealed uranium-rich volcanic rocks of the Ehu Lake Late-Middle Period in the basin should be the focus of the next phase of uranium exploration work using geophysical prospecting methods, mainly magnetic survey.


    Highlights: In Ganhang uranium metallogenic belt, it is very rare to produce Andesitic volcanic lava in the Ehu cycle. For the first time, this study clarified the characteristics of uranium-rich volcanic lava in Maquan Basin from the perspective of petrography and petrogeochemistry, and summarized the corresponding characteristics of volcanic activity and the process of uranium enrichment in rocks, which provided a relatively feasible idea for finding the favorable location of uranium mineralization in the red sand-covered
    area.


  • Regional Geology
    WU Bingwei, SUN Shouliang, ZHANG Jian, ZHOU Tiesuo, ZHANG Haihua, CUI Xiaolei, ZHANG Zijing, SUN Zhuan
    North China Geology. 2024, 47(4): 37-46.

    This paper is the result of geochemical research. 

    [Objective]The volcanic rocks of the Tiaojishan Formation in Western Liaoning not only represent the beginning of the Yanshanian large-scale volcanic eruption, but also are closely related to the time, scope and mechanism of the Craton weakening in North China.In recent years, a lot of new understanding has been obtained on the petrogenesis of the Tiaojishan Formation volcanic rocks, but itstectonic background, magmatic source area are still controversial. [Methods]Zircon U-Pb dating, Hf isotope composition and geochemical characteristics were analyzed in the core samples from the continuous drilling of borehole Yang D1. [Results]The results of zircon U-Pb dating show that the zircon U-Pb age of trachyte in the lower part of Tiaojishan Formation is 162.8±1.7 Ma, and the U-Pb age of tuff at the bottom of Tuchengzi Formation is 153.8 ±1.7 Ma. We believe that the volcanic rocks of Tiaojishan Formation formed in the Late Jurassic. In addition, the trachyte of Tiaojishan Formation is characterized by light rare earth enrichment, heavy rare earth deficit, and low Sr and Yb-type magmatic rocks, which indicates that the trachyte of Tiaojishan Formation is produced by partial melting of crustal magma under high pressure and accompanied by insignificant crystallization differentiation. The εHf (t) values of the zircons range from -22.1 to -15.4, and the two-stage model ages (TDMC) range from 2.182~2.604 Ga, indicating that the Tiaojishan Formation is mainly derived from the late Archean magma source, which indicates that the Tiaojishan formation was formed by the partial melting of the basic rocks in the lower crust under the background of the Pacific plate subduction to Eurasia continent. [Conclusions]The research results define the formation age and magma source area of the Tiaojishan Formation volcanic rocks, and provide a scientific basis for exploring the Mesozoic magmatic and regional tectonic evolution of the Yanshan orogenic belt. 

    Highlights:This article selects reliable continuous drilling core samples for the first time and applies zircon U-Pb geochronology and Lu Hf isotope analysis methods to provide new evidence for clarifying the age attribution and magma source area of the Tiaojishan Formation.The research results obtained provide a scientific basis for exploring the Mesozoic magmatic evolution and regional tectonic evolution of the Yanshan orogenic belt.

  • Hydrogeology and Envieronmental Geological Survey
    BAO Naili
    North China Geology. 2024, 47(4): 64-70.

    This paper is the results of geothermal energy. 

    [Objective]Zhecheng, Shangqiu, is located in a sedimentary basin,the Cenozoic deposits are thic, the thermal reservoir cap rock is good, the thickness of thermal sand layer is relatively large, so it has a good prospect of thermal storage. [Methods] Based on temperature data from 33 boreholes around Zhecheng, and more than 80 borehole geological data and regional 2-d seismic exploration results, the geological structure and geothermal field in this area are analyzed. [Results] This study clarified the cenozoic thickness and geological structure distribution in the study area, and analyzed the development history of geological structure. Through the analysis of borehole temperature measurement data, the geotemperature gradient and distribution law of geotemperature in this region are determined.The main factors controlling temperature distribution in the study area are analyzed. The distribution law of geotemperature gradient in Cenozoic and bedrock,thermal reservoir location and favorable geothermal target area are obtained, [Conclusions] the study shows that the difference of the earth temperature distribution is mainly controlled by the basement structure.The origin of the Cenozoic heat storage is mainly conduction type, and the conduction-convection-conduction plays a major role in the vicinity of bedrock and fault zone. 

    Highlights: Statistically summarized the geothermal gradient and distribution pattern in the region, and analyzed the geothermal genesis mechanism in the area.

  • HU Tianyi, LIU Huan, HE Weirong, KANG Quanquan, TANG Xiaodong, XU Qinglei
    North China Geology. 2024, 47(4): 80-90.

    This paper is the result of ground matrix survey. 

    [Objective] At present, the investigation of black land surface matrix is widely carried out in Northeast China, and various geophysical methods are important means to investigate the vertical structure characteristics of black soil surface matrix. In this paper, the typical surface matrix area in the Molidawa Daur Autonomous Banner ( Moqi for short ) of the Songnen Plain was selected to carry out micro-tremor exploration profile measurement and array measurement,so as to verify , the application effect of micro-tremor exploration method in the vertical structure investigation of black land surface matrix.[Methods] In this paper, the microtremor exploration technology combining artificial source and natural source surface wave is used. By extracting the surface wave dispersion curve of each measuring point for inversion analysis, the wave velocity and vertical spatial structure characteristics of different matrices are inferred by using the apparent shear wave velocity change, and the vertical structure characteristics of the surface matrix layer ( 0 ~ 40 m ) are obtained in combination with drilling verification.[Results] Based on the investigation of the micro-motion profile in the typical area of Moqi Banner, combined with borehole correction and regional physical parameters, the two-dimensional apparent shear wave velocity profile and three-dimensional array model of the study area were drawn. The spatial structure, soil type, soil matrix thickness and distribution characteristics of the surface matrix layer of 0 ~ 40m in these areas were explored, and the geological characteristics and apparent shear wave velocity range of the surface matrix layer in the study area were obtained. [Conclusions] Through this study, it is found that the combined exploration effect of artificial source and natural source surface wave is remarkable. Effectively combining the advantages of both can improve the exploration depth and shallow resolution, enhance the exploration ability of a single method, and is an effective geophysical method suitable for surface matrix layer investigation. It can provide scientific and effective data support for the vertical structure survey of surface matrix survey. 

    Highlights: ( 1 ) In this paper, a dual-source microtremor exploration method combining artificial source and natural source is used to improve the frequency band range of surface wave dispersion curve by mutual verification, thus improving the accuracy of shallow shear wave velocity structure. ( 2 ) Based on this method, the surface matrix investigation in the typical area of Moqi was completed, the spatial structure and soil type of the matrix layer were clarified, and the two-dimensional profile and three-dimensional model were constructed, which can provid scientific data support for surface matrix investigation and black land resource protection.

  • Rock and Mineral Analysis
    LI Guozhan , TU Jiarun , CUI Yurong , BI Junhui , HAO Shuang , LIU Wengang , ZHOU Hongying
    North China Geology. 2024, 47(4): 98-106.
    This paper is the result of maintenance the instrument.

    [Objective] The Inductively coupled plasma source (ICP) in the multi-collector Inductively coupled Plasma Mass Spectrometer (MC-ICP-MS) is a kind of high temperature ionization source under atmospheric pressure, which is produced by the interaction of several sophisticated components and is an important component of MC-ICP-MS, The Plasma Generation Process of the Mass Spectrometer is mainly performed by the ICP. It is necessary to strengthen its routine maintenance and failure analysis. [Methods] Taking the MC-ICP-MS(NEPTUNE) of Thermo Fisher Scientific as an example, This type of mass spectrometer mainly has plasma source fault, electronic fault, vacuum fault, gas support fault, circulating water support fault, etc. among which plasma source ignition fault is particularly common, and the influencing factors are complex. [Results] On the basis of a detailed introduction to the working principle of ICP and the maintenance experience of each of its components, the fault phenomena and treatment methods in the ignition process of this instrument are summarized in detail. [Conclusions]Pay attention to the routine maintenance and failure analysis of the plasma source can greatly improve the utilization of Neptune and ensure the acquisition of high-quality measurement data. It provide reference for the use and maintenance of the instrument.

    Highlights: ICP is the key core component of MC-ICP-MS,it is important to strengthen its daily maintenance and analysis the fault, which is of great practical significance to improve the utilization rate of large precision and valuable instruments and equipment and ensure the acquisition of high-quality measurement data.

  • Hydrogeology and Envieronmental Geological Survey
    LI Xiaoli, WANG Yudong, TIAN Haofei , LIU Henglin, LIANG Xingxing
    North China Geology. 2024, 47(4): 57-63+90.

    This paper is the result of debris flow hazard study.

     [Objective]The debris flow, because of its wide range, rapid disaster and great harm, has caused damage to the basic engineering fa‐cilities in the mountain area, and seriously hindered the regional economic development. In recent years, geological disasters have occurred frequently in the mountainous areas of Beijing. Yanqing District, as the ecological conservation area of Beijing, has many tourist attractions, but there are also many hidden dangers of debris flow. [Methods]In order to reduce the potential threat of debris flow, it is very important to study related debris flow in Yanqing District. In this paper, the debris flow ditch in Chashikou village of Yanqing District is taken as the research object to analyze and forecast the risk. [Results]The results show that loose deposits of Maoshangou can be categorized into three types: alluvial and diluvial deposits, residual-slope deposits, and artificial deposits, with a dynamic reserve of 9.9 × 104 m3 . From the peak flow value and the total amounts of solids washed out by the primary debris flow, it can be determined that the size of this debris flow is medium. By varying rainstorm frequencies (10-, 20-, 50-, 100-year rainfall events), the respective hazardous areas are measured to be 0.004 4, 0.005 1, 0.005 9, and 0.006 8 km2 . The stage of debris flow devel‐opment is considered to be a recession period. [Conclusions]After thorough discussions, it was found that the chances of the debris flow gully erupting into a medium-sized debris flow are high, which will pose a hazard to the residents of the downstream roads and villages. The detailed study of this ditch not only helps to deeply understand the mechanism, dynamic characteristics and develop‐ment trend of the debris flow in this region, but also provides a reference for the study of debris flow and disaster prevention and control of the single ditch under similar geological conditions. 

    Highlights: At present, there is relatively little research on single-channel debris flow in Beijing area, especially in Yanqing area. In this paper, the breeding conditions and basic characteristics of Maoshan Ditch in Yanqing area are studied. In terms of predicting the scope of potential danger areas, this study introduced the influence of terrain change and flood peak discharge on debris flow, so as to make the prediction results more accurate and provide a reference for subsequent scientific research and disaster prevention and mitigation practice.

  • Rock and Mineral Analysis
    ZENG Jiangping, WANG Na, LIU Yibo
    North China Geology. 2024, 47(4): 106-110.

    This paper is the result of titration of total nitrogen content in rocks. [Objective] This article established an analytical method for determining total nitrogen content in rocks using a fully automatic Kjeldahl nitrogen analyzer by conducting research on optimizing digestion procedures, distillation time and other experimental conditions, as well as accuracy of methods. [Methods] This method added sulfuric acid during the digestion process, and the nitrogen-containing organic matter in the sample was transformed into inorganic ammonium nitrosulfate. Under the action of a catalytic plate that made of potassium sulfate and pentahydrate copper sulfate, the reaction was accelerated, and ammonia gas was released by reacting with sodium hydroxide which was collected in a boric acid solution and titrated with standard hydrochloric acid solution for total nitrogen. [Results] The results showed that the detection limit of the method was 23.90 μg/g and the method was validated using the national first-class standard material GBW 07729, with a relative standard deviation (RSD) of 1.07% (n=4), and the recovery rate of the experiment was between 95.40% and 103.8%. [Conclusions] This method used a fully automatic Kjeldahl nitrogen analyzer to determine the total nitrogen content in rocks which is simple and accurate, and could fully meet the testing requirements of the geological industry. 

    Highlights: 1. By optimizing the experimental conditions, a method for determining the total nitrogen content in rocks has been es‐tablished. 2. The use of fully automatic Kjeldahl nitrogen analyzer elimenated the errors caused by human factors in determining thetitration endpoint, and improvd the testing accuracy

  • XU Jianchun, LIU Yanxu, LI Wenyong, QIAO Chungui, CAO Anqi
    North China Geology. 2024, 47(4): 91-97.
    This paper is research of magnetic anomaly.

    [Objective] East Tibet is located in the southwest Sanjiangmetallogenic belt with good metallogenic conditions. In this paper, based on the aeromagnetic survey results of the geotransport project, the aeromagnetic anomalies with good abnormal shape (Zang 16-35) were selected for comprehensive investigation of the geophysical and geochemical surface, and the causes of the anomalies were identified. [Methods]The geological profile survey, high precision ground magnetic survey, soil geochemical profile survey were carried out, and the cause of the anomaly was analyzed by means of profile inversion. [Results]The results show that there is an obvious malachite mineralization alteration zone on the surface, located in quartz diorite, and the shape of the ground magnetic anomaly is regular, the element content is higher than the background value, and the location of the geophysical and geochemical anomaly corresponds well. [Conclusions]It can be inferred that the survey area where the anomaly is located has a good prospecting prospect, and it also has reference significance for the verification and prospecting of other anomalies in this area.

    Highlights: large-scale aeromagnetic survey was carried out for the first time in the study area where the anomaly was located, and high-precision aeromagnetic data was obtained in the study area. Comprehensive ground examination for physical and chemical characteristics of the Zang16-35 anomaly with good shape was carried out, and the cause of the anomaly was identified, providing support for the next step of prospecting in the study area.

  • Hydrogeology and Envieronmental Geological Survey
    ZHANG Xi , HAN Bo , DU Yanan , GONG Xue , LI Houen , ZHEN Zhen
    North China Geology. 2025, 48(1): 78.

    This paper is the research of groundwater monitoring. 

    [Objective] In order to accurately obtain the basic information of groundwater, build a groundwater monitoring system, and ensure the orderly promotion of large-scale engineering construction and the construction of the ecological city of“water city communion”, Xiong’an New Area has implemented a shallow groundwater monitoring well construction project. [Methods] On the basis of the original national and provincial monitoring wells, the construction of shallow groundwater monitoring wells and the online monitoring system for the Xiong’an New Area were carried out in accordance with the distribution, recharge, runoff and discharge conditions of the shallow groundwater. [Results] The groundwater monitoring network consists of 41 groups and 109 wells has constructed in Xiong’an New Area, with a monitoring area of 1770 km2 , the main monitoring layers are the pore water aquifer of the loose sediments of the Quaternary with a shallow depth of 50 m (phreatic water and shallow confined water), and a comprehensive groundwater monitoring network integrating the collection of groundwater information, transmission, analysis and related services has been built. [Conclusions] The implementation of this project can realize comprehensive and systematic monitoring of shallow groundwater up to 50 m in Xiong’an New Area, which greatly improves the monitoring capacity of shallow groundwater, ensures the timeliness and accuracy of shallow groundwater information, and provides important basic data nd technical support for the high-quality construction and management of groundwater in Xiong’an New Area. 

    Highlights: An automatic monitoring network for shallow groundwater stratification was built for the first time in Xiong’an New Area. The monitoring of shallow groundwater in the Xiong’an New Area is divided into 3 to 4 layers, which greatly improves the monitoring accuracy and monitoring capacity of shallow groundwater, and provides important basic data and technical support for the high-standard and high-quality construction of the Xiong’an New Area and the government’s decision-making on water resources management.

  • Regional Geology
    WANG Cunzhu, ZHANG Bin , ZHENG Dahe, LI Guojun, MA Chao
    North China Geology. 2025, 48(1): 11.

    [Objective] The tectonic location of granitic mylonite in Qingling area of Jilin Province is located in the eastern part of the northern margin of the North China plate. The research is the great significance to the evolution of the Paleo-Asian Ocean tectonic domain and its transformation with the tectonic system of the Paleo-Pacific tectonic domain. [Methods] In this paper, it is the first time to study the petrography, LA-ICP-MS zircon U-Pb chronology and geochemical characteristics of the rock to determine its emplacement age, petrogenseis and its tectonic background. [Results]The zircon of granitic mylonite is semi-automorphic-automorphic and the oscillatory growth zone is obvious, suggesting its magmatic origin. The dating results show that the granitic mylonite was formed at 291±3.0 Ma, which is the product of the Early Permian magmatic event. The 40Ar/39Ar plateau age of biotite is 182.01±0.38 Ma, suggesting that the metamorphic deformation age is Early Jurassic. EBSD fabric analysis shows that the rocks in this area have undergone a regressive process of medium-high temperature to medium-low temperature to low temperature.The rock is characterized by high silicon (68.26% - 75.91%), high aluminum (12.32% - 15.17%), poor iron (Fe2O3 is 0.03-3.38), and geochemical characteristics show peraluminous. The rocks are enriched in light rare earth elements, depleted in heavy rare earth elements, and the differentiation of light and heavy rare earth elements is obvious. [Conclusions] The above characteristics indicate that it is the product of partial melting of argillaceous rocks in the lower crust. The 40Ar/39Ar plateau age of biotite is 182.01±0.38 Ma, suggesting that its metamorphic deformation is Early Jurassic. Combined with regional geological characteristics, the emplacement of Early Permian granitic mylonite should be related to the southward subduction of the Paleo-Asian Ocean. The metamorphic deformation of the granitic mylonite occurred in the early Jurassic, which may be related to the subduction of the Paleo-Pacific plate to the Eurasian plate. 

    Highlights: The Early Permian granitic mylonite was identified in the Qingling area of Jilin Province for the first time, and its systematic petrology, petrochemistry, isotope chronology and metamorphic deformation were studied. It is believed that its formation time is 291±3.0 Ma, and the deformation time is 182.01±0.38 Ma. Granitic mylonite was formed in the process of island arc magmatic activity under the background of subduction, indicating that the Early Permian Paleo-Asian Ocean Plate subducted to the North China Plate, and the Early Jurassic Paleo-Pacific Plate may begin to subduct to the Eurasian Plate.

  • Regional Geology
    LIU Yang, TENG Fei, GUO Shuo
    North China Geology. 2025, 48(1): 1.

    This paper is the research of tectonic deformation. [Objective] During the Indosinian orogeny, the collision and convergence of the South China, North China, and Qiangtang terranes triggered extensive granitic magmatic intrusions and fold deformation in the Songpan-Garzê region. To investigate their tectonic setting and evolutionary processes. [Methods] the authors analyzed the mineral compositions and geochemical characteristics of granitic intrusions.[Results] Four main types of granitic intrusions were identified: (1) biotite ± amphibole high-K calc-alkaline type, (2) peraluminous calc-alkaline type;(3) high-K alkaline type; (4) leucogranite type. Based on macro - and micro-structural features and regional unconformities, the tectonic deformation during this period was divided into two principal phases: D1 and D2.[Conclusions] The diverse types of granitic intrusions and structural deformations from different stages correspond to distinct tectonic environments during the syn-orogenic (collisional) and post-orogenic (extension) phases of the Indosinian orogeny. 

    Highlights:This study correlates the Indosinian magmatism with tectonic deformation in the Songpan-Garzê region and systematically investigates the tectonic-magmatic evolutionary processes during the Indosinian period.

  • Regional Geology
    WANG Langlang, WEI Tao, ZENG Zhaoxia, RAN Wenrui, CHEN Qian, LIU Yun
    North China Geology. 2025, 48(1): 44.

    This paper is the result of sedimentary environment. [Objective]The Middle Jurassic Yaopo Formation in the Muchengjian area of Xishan, Beijing, belongs to typical continental lacustrine deposits. This set of strata is the best developed and fully exposed sedimentary of Middle Jurassic sandstone, but its grainsize characteristics are not researched, which restricts the analysis and reconstruction of the Middle Jurassic sedimentary environment in North China. [Methods] Based on the outcrop profile of Panjiagou in Muchengjian area, Western Beijing, this paper calculates the relevant particle size parameters and Sahu function discriminant values through microscope observation, statistics and analysis, and the probability particle size curve, Friedmann particle size parameter scatter plot and C-M diagram were drawn, and the relevant parameters and images were comprehensively studied and analyzed, and the grain size characteristics and sedimentary environment of the sandstone of the Yaopo Formation were summarized. [Results] Relevant grain-size parameters of 18 sandstone samples from the target profile of the study area were as follows: (1) the average particle size ranges from 0.57-3.54 φ; (2) Standard deviation σ ranges from 0.42 to 1.03; (3) Skewness (SK1) range - 2.36-0.79; (4) kurtosis (KG) ranges from 0.90 to 1.27; the probability granularity accumulation curves are typical two-stage, three-stage and multi-stage forms. The C-M diagram of the sample shows that the sediments are mainly suspended and gradually suspended, which represent typical traction flow deposits. [Concluslions] SK1-σ1 scatter plots, probability accumulation curves, C-M plots, show that the sedimentary environment in the study area is shallow lake and delta sedimentation. 

    Highlights: The grain-size analysis method was systematically used to study and analyze the sandstone of Yaopo Formation in Muchengjian area of Xishan, Beijing for the first time, and the characteristic values of relevant grain-size parameters were obtained. At the same time, through comprehensive research analysis, beach-bar deposits in the area was firstly proposed.

  • Regional Geology
    LIU Yankai, LI Kang , XU Shaopu, ZHANG Shaoshuai
    North China Geology. 2025, 48(1): 67.

    This paper is the research on cobalt-nickel deposits. [Objective] Northern Hebei is located near the eastern part of the northern margin of the North China Craton, which is in the metallogenic prospect area of magmatic cobalt-nickel deposits on the northern margin of North China Craton, and there are abundant clues to cobalt-nickel mineralization. The study of the metallogenic conditions and types of cobalt-nickel deposits in Hebei Province is helpful to clarify the metallogenic potential and prospecting prospect of cobalt-nickel deposits in the province.[Methods] By summarizing the typical cobalt-nickel deposits at home and abroad, the ore-forming geological conditions in the province are compared. Based on the comprehensive analysis of relevant geological and mineral data, the metallogenic background, metallogenic regularity and prospecting potential of cobalt-nickel deposits in the province are summarized and analyzed. [Results] There are a large number of basic-ultrabasic rock bodies related to cobalt-nickel mineralization in the province, the strata and regional structures related to cobalt-nickel mineralization are widely distributed, and the cobalt-nickel ore-forming geological conditions are superior. The known cobalt-nickel deposits in the province are divided into nine genetic types of cobalt-nickel deposits related to intrusive magmatism, contact metasomatism, volcanism, ore-bearing fluid and sedimentary diagenesis, and the characteristics of mineralization, distribution and quantity of various types of cobalt-nickel deposits are summarized. [Conclusions] The nickel-cobalt deposits in Hebei Province have superior ore-forming geological conditions, rich and diverse genetic types, especially magmatic and skarn types have good metallogenic potential and prospecting prospect. 

    Highlights: The metallogenic geological conditions of cobalt-nickel deposits in Hebei Province are systematically summarized for the first time, and the genetic types of cobalt-nickel deposits in Hebei Province are comprehensively sorted out and summarized.

  • Regional Geology
    CHENG Xianyu , HE Peng , TENG Fei , WU Haixin , TIAN Hui , SUN Lixin
    North China Geology. 2025, 48(1): 58.

    This article is the result of rock chronological research. [Objective] Multiple periods of granitic magmatic activity have developed in the Qinglong Kuancheng area of eastern Hebei Province, previous studies on the Dashizhu rock mass are relatively weak compared to the Dushan pluton, which is the largest Mesozoic intrusive rock in the eastern Hebei province. The formation age of the Dashizhu rock mass has always been controversial.This article aims to explore the formation age and geological significance of the Dashizhu rock mass in Kuancheng, eastern Hebei Province. [Methods] This article conducted LA-ICP-MS zircon U-Pb dating on the Dashizhu rock mass in Kuancheng County, Chengde, redefine the formation age of the intrusion body of the Dashizhu, which is disintegrated through regional geological survey.[Results] The Dashizhu pluton is divided into three stages. The stage of adamellite is divided into central and marginal phases according to mineral particle size, the authors selected two monzonitic granites diagenetic ages of 226 Ma and 214 Ma, which belong to the Late Triassic of the Mesozoic era. [Conclusions] Based on regional comparison and comprehensive research, it is preliminarily believed that the Kuancheng Dashizhu rock mass is a northeast intrusive extension of the southwestern Dushan pluton, the result will provide new ideas for searching gold mineralization zones in the eastern Hebei Province. 

    Highlights:Through zircon U-Pb geochronology and division of the Dashizhu rock mass, it is determined that the Dashizhu rock mass was formed in the Late Triassic. This result has important indicative significance to search Mesozoic gold deposits in eastern Hebei Province.

  • Regional Geology
    SHI Shujing , KANG Zhiqiang , ZHANG Qinjun , ZHENG Huanjun , FENG Minhao , BEI Weichang
    North China Geology. 2025, 48(1): 103-112.

    This paper is the result of CO2 geological storage research. 

    [Objective] The geological storage of CO2 is an effective approach to address climate change, reduce CO2 emissions, achieve carbon neutrality, support environmental protection and energy resource security, as well as to promote the harmonious coexistence of economic development and ecological protection. [Methods] This study focuses on the Hepu Basin in Guangxi as the research unit. Based on the geological characteristics, the deep saline aquifer was identified as the geological reservoir. The D-level predicted geological potential during the reconnaissance phase was calculated using the mechanisms of residual trapping and solubility trapping. Seven primary indicators and sixteen secondary evaluation indicators were selected to conduct the suitability assessment for CO2 geological storage.[Results]The results indicate that the D-level predicted geological potential for CO2 storage in the saline aquifer of the Hepu Basin is 189.01×10⁶ . The suitability evaluation results for the two assessment units, Xichang Depression and Changle Depression in the Nanliujiang Depression, are "moderately suitable". [Conclusions] The evaluation results provide a scientific basis for the preliminary site selection for CO2 geological storage project construction in Guangxi. 

    Highlights:On the basis of sorting out the geological background conditions, the D-level predictive geological potential for carbon dioxide in saline aquifers during the exploration phase was calculated using the mechanisms of trapped storage and dissolved storage. A comprehensive evaluation system was established, comprising 7 primary indicators and 16 secondary evaluation indicators, for assessing the suitability of CO2 geological storage. This provides a scientific basis for the preliminary site selection of CO2 geological storage engineering construction in Guangxi, and holds significant practical guiding value.

  • Hydrogeology and Envieronmental Geological Survey
    LIU Jihong, ZHANG Surong, GAO Xuesheng, ZHANG Guoli, SU Yongjun, LIU Hongwei
    North China Geology. 2025, 48(1): 113.

    This paper is the study of soil selenium and enrichment factors. [Objective] The spatial variation of selenium in the soils of Xiaoertai Town, Zhangbei County, is significant, with some areas exhibiting clear surface enrichment. Identifying selenium sources and enrichment factors is crucial for the future development and utilization of selenium-rich land resources. [Methods] This study analyzed the soil geochemistry data of Xiaoertai Town, Zhangbei County, using correlation analysis, variance analysis, and GIS spatial analysis methods to explore selenium content, spatial distribution, and enrichment factors. [Results] The results showed that the content of Se in the topsoil of Xiaoertai Town was 0.17 mg / kg), which was higher than that of the background soil (0.15 mg / kg). The area with selenium content above the natural enrichment standard (≥0.3 mg/ kg) accounted for 8% of the study area. Selenium-enriched soils were mainly found in areas along developed river systems and low-lying zones on either side of the rivers. Factors such as parent material, soil type, and land use influenced selenium content and enrichment levels. Correlation analysis revealed a significant negative correlation between selenium and pH, and a significant positive correlation with organic carbon. [Conclusions]This study provides valuable insights for the development and utilization of selenium-rich land in Zhangbei County. 

    Highlights:For the first time, the geochemical characteristics of soil selenium in the study area were systematically summarized, and the sources of soil selenium were preliminarily determined based on the parent material and relevant geological background. Possible factors affecting soil selenium enrichment were analyzed from multiple aspects such as soil type, land use type, and soil physicochemical properties.

  • Regional Geology
    LIU Ruiyang
    North China Geology. 2025, 48(1): 24-43.

    This paper is the result of rock geochemistry. [Objective] Xiaozhushan is located in the eastern extension of the northern Jiaonan Uplift, Sulu orogenic belt, Shandong Province,adjoining the Wulian-Qingdao fault. Mesozoic granites are widely exposed in this area. In the process of field exploration, the lightcolored granite profile with large mineral particles were founded, which determined as highly differentiated granite by geochemical tests. Highly fractionated granite is an important symbol of continental crust composition maturity. This study plays an important leading role in improving the types of granites in the study area, evaluating the ore-bearing potential of the study area, and exploring the large igneous rock province in eastern Shandong Province. [Methods]The petrography, major, trace and rare earth elements in whole rock, Sr-Nd-Pb isotope, zircon U-Pb dating and in-situ Hf isotope, X-ray diffraction and laser Raman spectroscopy, plagioclase electron probe and in-situ elemental scanning analysis of 8 samples obtained in the Xiaozhushan area were carried out, and the following conclusions were obtained. [Results]Petrography shows that the granite in the study area contains S-type granite characteristic mineral-cordierite, with pegmatite veins. The 10 000 Ga/Al-Zr diagram shows the granite rock type, belong to I and S granite. All samples are high-silica granites (SiO2 >71.9%) with high total alkali content (Na2O+K2O >8.5), belonging to the highpotassium calc-alkaline series. Calculation of the index of highly fractionated granites: most samples with obvious Eu negative anomaly (δEu=0.4-0.5) and the aluminum saturation index is higher (A/CNK >1.2), the differentiation index (DI) is above 90, and the saturation temperature of zircon reflects the magma origin temperature is 832-875 °C. Zircon Ti thermometer reflects that the crystallization temperature of magma is 618.8-726.44 ° C, which shows that magma differentiation experienced obvious cooling process. S-Nd-Pb isotopes show high ISr and low εNd(t), indicates that the sample magma source area is crust. Geochronology shows that the samples` age is 116.4 Ma, which belongs to the Early Cretaceous highly fractionated granite. [Conclusions]The above conclusions show that the highly differentiated granite in the study area is mainly crust-derived material, and mixed with mantlederived material. The process of differentiation experiences the separation and crystallization of minerals such as plagioclase and the accessory minerals like zircon and apatite. The magma rises along the cracks in the island arc, forming highly fractionated granite with ore-bearing potential. 

    Highlights: In this study, S-type granite was found in Xiaozhushan area. Through geochemical analysis, the source of rock material and tectonic background were clarified.

  • Hydrogeology and Envieronmental Geological Survey
    LI Jun , LI Zhuang , MIAO Jinjie , LIU Hongwei , LIU Xiao , GAO Yihang
    North China Geology. 2025, 48(1): 95-102.

    This paper is the result of geological hazard survey engineering. [Objective] To systematically analyze the material composition and deformation and failure characteristics of Baiyao landslide, the stability of landslide in the studied area is evaluate, reference is provided for urbanization construction and development, and guidance for regional landslide disaster prevention and control is provide. [Methods] Based on the field geological survey and field drilling, the material composition, deformation and failure characteristics of the landslide in Beiyao village, Yangcheng County, Shanxi Province, are analyzed in this paper. The stability coefficient of the landslide under different working conditions is calculated according to GB/T32864—2016, and the stability evaluation is carried out. [Results] (1) The main sliding direction of the landslide in Beiyao village is about 30°, the top elevation of the landslide slope is 750 m, the foot elevation is 629 m, the height difference is about 121 m, and the slope is about 30°. The landslide body length is about 305 m, the width is about 660 m, the thickness of the landslide body is about 5—10 m, the area is about 201 300 m2 , and the volume of the landslide body is about 1.61 ×106 m3 . (2) According to the geological environment conditions of the landslide area, the stability of the landslide under two working conditions is calculated. Under the conditions of dead weight, the landslide is in a basically stable state; under the conditions of dead weight and heavy rain, the landslide is in an understable state. (3) By collecting the monitoring data of the automated surface displacement monitoring station, the deformation trend of the area where the GNSS01 and GNSS03 monitoring points are located in the landslide profile of Beiyaocun is obvious, with periodic characteristics and experiencing multiple step reduction. In addition, the fractures in this area are also in a continuous deformation stage. (4) This area has the topographic conditions for the formation of landslides. The rock and soil composed of slopes have low strength and are easy to soften when exposed to water. The structural plane is consistent with the slope direction, and the precipitation infiltration increases the sliding weight, decreases the anti-sliding force and increases the sliding force, which destroys the original stress balance of the slope and makes it easy to slip. [Conclusions] The slope deformation of Beiyao Village landslide is obvious, in which the foundation of buildings near the front is disturbed and most of them collapse. In addition, topography is the necessary condition for landslide formation, slope lithology is the material basis of landslide formation, and water plays a catalytic role in landslide formation and is an important inducement factor. The results of this study can provide reference for regional urbanization construction and development, and provide guidance for regional landslide disaster prevention. 

    Highlights: Based on the results of field geological survey and field drilling, the development and deformation characteristics of landslide in Beiyao Village are systematically studied, and the causes and influencing factors of landslide in the study area are discussed and analyzed according to the monitoring data of integrated monitoring equipment.

  • Hydrogeology and Envieronmental Geological Survey
    ZHANG Xi , HAN Bo , DU Yanan , GONG Xue , LI Houen , ZHEN Zhen
    North China Geology. 2025, 48(1): 87-94.

    This paper is the study on the influence of moisture conditions on the frost heave characteristics.

     [Objective] Frost heave is a common disease in the subgrade engineering of seasonal frozen soil areas. The aim of this paper is to systematically understand the frost heave laws of typical soil types in the seasonally frozen soil area. [Methods] This paper takes undisturbed natural silt clay obtained from in-situ drilling as the research object. A multi-channel fiber Bragg grating temperature measurement system is used to monitor the movement of the freezing front. A single-factor frost heave test is adopted to conduct closed/open system freezing comparison tests at temperature gradients of ﹣5 °C, ﹣15 °C, and ﹣25 °C. The characteristics of frost heave under different moisture conditions are explored. A wider range of natural initial moisture contents of undisturbed soil samples is selected to grasp the overall trend of rate changes frost heave. The main conclusions supplement and improve the previous research results. Under the closed system conditions, the change trends are basically the same, but under open system conditions, there are differences in the change trends, change boundary points, and extreme points of the frost heave rate. At the same time, a frost heave prediction equation under the influence of two factors is constructed. [Results] The results show that both the initial moisture content and the water replenishment conditions have a significant impact on the frost heave rate. Under closed system conditions, the frost heave rate of the soil increases first and then tends to be stable as the initial moisture content increases. Under open system conditions, it shows a parabolic response. The frost heave rates under different water replenishment system conditions differ by 2 to 5 times. The intrinsic factor determining the frost heave characteristics of natural silt clay is its structure. [Conclusions] The critical moisture content control indicators (24% for open system and 31% for closed system) and the frost heave prediction equation are proposed, which can provide certain references for the prevention and prediction of frost heave of silt clay in engineering projects in seasonally frozen soil areas with frequent groundwater activities. 

    Highlights:The field drilling of the original silty clay in the seasonal frozen area and different moisture content ranges were selected for frost heave tests to reveal the structural effects of frost heave in undisturbed soil, propose moisture thresholds for frost heave prevention and control, and analyze multimodal frost heave responses. the main conclusions complement the previous research results, and can provide data support for frost heave prevention and controlling and frost heave rate prediction.