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.

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.

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.

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.

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.

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.

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.

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.

[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.

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.

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

[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.

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.

[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.

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.

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.

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.

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.

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.

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.

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.

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.

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.