Most Download articles

Published in last 1 year| In last 2 years| In last 3 years| All| Most Downloaded in Recent Month | Most Downloaded in Recent Year|

Published in last 1 year

Please wait a minute...


For Selected: Download Citations EndNote Ris BibTeX Toggle Thumbnails

Select

Characteristics of Stromatolites and Its Significance in Depositional Environment Reconstruction of the Mesoproterozoic Longjiayuan Formation (2nd Member), Western Henan LI Qianqian, ZHENG Deshun Geoscience    2023, 37 (04): 845-857.   DOI: 10.19657/j.geoscience.1000-8527.2022.023 Abstract （152）   HTML （27）    PDF（pc） （12773KB）（281）       Knowledge map    Save Stromatolites recorded the life activities of early environment, cyanobacteria and microbial community, and their growth morphology was influenced by the sedimentary environment, which is of great significance for the paleo-environmental reconstruction. Stromatolites from the Longjiayuan Formation (2nd member)of the Mesoproterozoic Guandaokou Group in western Henan have various morphological types and concentrated in distribution, which is a typical area for stromatolites development. The distribution of stromatolites is closely related to global events, geochemical environment of the Precambrian ocean and the development of microbiolites, yet detailed research is still lacking. Based on this, we conducted a systematic field investigation and petrological examination on the microbialite structure on these stromatolites, studied the macroscopic and microscopic characteristics of the stromatolites, established the sedimentary environment evolution and sedimentary model, and compared with the stromatolites from other areas. The results show that the macroscopic morphology of the stromatolites can be divided into horizontal laminae, ripple, hilly, cone, and column. Microscopically, the stromatolites are light and dark laminae, with few ooids, spherular and detrital materials locally. The shape and scale of stromatolites are closely related to the hydrodynamic conditions and water depth. Horizontal laminated stromatolites were developed in the intertidal zone, whilst corrugated and mound stromatolites were developed in the intertidal high-energy zone and low-energy zone. Meanwhile, cone and columnar stromatolites were developed in the subtidal zone. Our comprehensive analysis shows that our stromatolite samples were formed in a tidal-flat environment, and were influenced by the sedimentary evolution process of intertidal, subtidal and intertidal zones. It is beneficial to analyze the Early Mesoproterozoic development environment of microbiolites in the southern margin of North China. Besides, we compared our results with the sedimentary environment of microbiolites in Jixian area (northern margin of North China), in order to explore the relationship between marine environment, atmospheric environment, and microbiolites around the North China Craton. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Advances on the Understanding in the Emeishan Mantle Plume and Dynamic Mechanism of the Permian Sichuan Basin Formation SUN Ziming, BIAN Changrong, LIU Guangxiang Geoscience    2023, 37 (05): 1089-1099.   DOI: 10.19657/j.geoscience.1000-8527.2023.043 Abstract （139）   HTML （18）    PDF（pc） （4559KB）（257）       Knowledge map    Save In recent years, significant research progress has been made on the Emeishan Large Igneous Province (ELIP) and its genetic mechanism of mantle plume, but the scope of the mantle plume on the Sichuan Basin and the dynamic mechanism for the Permian sedimentary basin formation remain unclear.Based on a number of literature research and recent studies, and the idea that deep mantle activity controls the evolution of crustal surface system, the characteristics of Emeishan LIP and its deep geology are systematically reviewed.It is recognized that the mantle plume is the dominant factor that induces the large-scale eruption of the Emeishan basalts and formed the LIP, and has direct influence on some parts of the Sichuan Basin, which is manifested by the differential denudation of the top Middle Permian Maokou Formation.This was likely caused by the upwelling of mantle plume and its control on the Permian sedimentation and sedimentary facies distribution in the central-southern part of the basin.Formation of the extensional troughs, and the alternating high-and-low sedimentary-tectonic framework in the central-northern Sichuan Basin during the Permian to Early Triassic may have been mainly controlled by the extension of the southern Qinling Ocean. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Fluvial Geomorphology of the Eastern Altyn Tagh and Its Tectonic Activity Implications LU Fang, GAO Mingxing, ZHOU Shuxian, WANG Shun Geoscience    2023, 37 (05): 1100-1109.   DOI: 10.19657/j.geoscience.1000-8527.2023.020 Abstract （103）   HTML （11）    PDF（pc） （8829KB）（249）       Knowledge map    Save The Altyn Tagh strike-slip fault zone is the major control fault at the northern margin of the Qinghai-Tibet Plateau, and plays a vital role in the Cenozoic crustal deformation of the plateau.We extracted and calculated five geomorphic indices (slope, relief amplitude, fractal dimension, hypsometric integral, and stream length gradient) of 173 sub-basins by ArcGIS software.The geomorphic indices of each sub-basin were classified into five types.Their arithmetic mean values were used as relative tectonic activity indices, in order to quantitatively analyze the topographical features and the tectonic activity intensity.We show that Altyn Tagh strike-slip fault zone is the dividing line for the relative tectonic activity intensity of the whole study area, and the relative tectonic activity index level gradually decreases from south to north, and from high to low mountai-nous areas.From the spatial distribution of the relative activity tectonic index grade, the tectonic activity in the Danghe and Yemahe River basins appears to be stronger, and the intensity gradually decreases from west to east.In addition, we combine the influence of rocks, precipitation, and tectonics on the geomorphic index.Our results show that tectonics is the main factor controlling the geomorphic development in the watershed of the Altyn Tagh strike-slip fault zone, the relative tectonic activity intensity in the watershed where the seismic point is located, the watershed on both sides of the fracture zone, and the stress transition zone are higher than those in other surrounding watersheds. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Route Planning and Ponder of Geoscience Study Travel in Hualong County, Qinghai Province LI Junlei, ZHANG Xujiao, WANG Yifan, ZHANG Xiangge, WANG Chongge, YUAN Xiaoning, LIU Xinlan, WANG Kaiya, RAO Haoshu, LIU Jiang, QIN Yuan Geoscience    2023, 37 (05): 1411-1422.   DOI: 10.19657/j.geoscience.1000-8527.2023.113 Abstract （94）   HTML （11）    PDF（pc） （12118KB）（230）       Knowledge map    Save Geoscience study travel is a new engine to utilize the resources of geological heritage to carry out the popularization of geoscience, which in turn leads to geotourism. Yet, due to the fact that the guiding ideology and methodology of study route planning are still unclear, there are problems such as limited study objects, superficial course contents, insufficient scientific inquiry, and emphasizing on touring but not on studying, etc. in geoscience study in general. Hualong County in Qinghai Province, which is located in the upper reaches of the Yellow River, preserving significant geological heritage such as the convergence of Rodinia supercontinent, the subduction and closure of the Proto-Tethys Ocean, the uplift of the Tibetan Plateau and the Yellow River evolution, etc., which is a unique resource to carry out geoscience study travel. This paper discusses the design ideas of geoscience study planning from the guiding ideology, scientific questions and supporting facilities, taking Huarong County as an example.Based on the detailed field geological survey, the characteristics, types, distribution and scientific value of geological heritage in Hualong County have been systematically researched and deeply excavated. Taking the Early Paleozoic Ophiolite Suite in Laji Mountain, Xining Group-Hualong Complex Angular Unconformity, Danxia landform, Red Soil Forest landform and paleoseismic dammed-lake as the key points of the study, we have planned out the Lamu Gorge-Heshijia “the Meeting of one Billion Years”, Ahetan Village-Gongbo Gorge “Flowing Water-the Sculptor of Nature”, Keba Village-Jinyuan Township “Double-edged Sword of Neotectonic Movement”, Yaoshuiquan-Ansiduo Township “Conversion of Sea and Land with Ophiolite”, Xiaqiong Temple-Gangshan Mountain “the Winding Yellow River, the Forest Sea of Plateau”, a total of five geoscience study routes. It also proposes the methods of planning and designing geoscience study routes oriented by geoscience questions and guided by the earth system view and the theory of harmonious coexistence between man and nature. It can provide a scientific basis for the development of geotourism in Hualong County, and also has a certain reference value for the development of geoscience study in other areas. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics, Genesis and Evolution of Daigu Landform in Yimengshan UNESCO Global Geopark CAI Yinlu, WU Fadong, HAN Jinfang, HUANG Zhen, ZHOU Ying, LIU Baoyin, CHEN Yangyang Geoscience    2023, 37 (04): 1065-1074.   DOI: 10.19657/j.geoscience.1000-8527.2023.085 Abstract （539）   HTML （8）    PDF（pc） （12188KB）（218）       Knowledge map    Save The Yimengshan UNESCO Global Geopark (UGGp) is the origin of the “Daigu Landform”. Through field investigation of the characteristics of Gu landform, based on the measurement of river valley stratigraphy and profiles, and using the OSL dating of the river terrace to calculate the cutting rate, the formation time of Daigu Landform has been determined. The results show that the geomorphological features of the Daigu Landform are related to the strata lithology of the Gu body. Daigu Landform is a type of mesa structure, with a flat top, steep margin and gentle slope. Gu body is mainly composed of two strata with different lithologies: The top comprises Cambrian limestone with strong weathering resistance but develops many joints, while the Gu body with weak erosion resistance is dominated by mudstone and siltstone. We estimated that the formation time is about 1.77 Ma by using the erosion rate, based on the dating results of the river terrace. The Daigu Landform formation and evolution can be divided into four main stages: (1) the material was formed in the Early Cambrian; (2) tectonic uplift, and the strata gradually exhumed and the shaping stage began; (3) long-term weathering and denudation of various external forces, such as surface water that gradually created the mature Daigu Landform; (4) the landform ended its development when the upper limestone collapsed. The systematic study of the Daigu Landform has great importance in understanding the Daigu Landform and its scientific value, which also contributes to the spreading of geoscience knowledge of UGGps. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Controlling Factors and Types of Geomorphologic Landscapes in Danxiashan UNESCO Global Geopark of China GUO Fusheng, LING Yuanyuan, CHEN Liuqin, ZHOU Wanpeng, LI Hongwei, CHENG Liangkai, WU Zhichun, LI Guangrong, GUO Zhen, LI Bin Geoscience    2023, 37 (06): 1665-1679.   DOI: 10.19657/j.geoscience.1000-8527.2023.099 Abstract （39）   HTML （11）    PDF（pc） （50465KB）（215）       Knowledge map    Save Danxiashan UNESCO Global Geopark is characterized by well-developed Danxia landscape in humid climate of South China, where geomorphologic features and genetic analysis of individual landforms have received much attention in previous studies. However, the controlling factors of landscape development across the Danxia Basin remain poorly understood, and the relationship between fault systems and peaks is yet to be well recognized. In this study, methods such as field survey, rock hardness measurement, remote sensing interpretation of liner structures, and experimental analysis of rock samples were used to illustrate the roles of lithology, depositional facies, and tectonic uplift and dissection in shaping the landscape evolution and to propose a gene-tic and morphologic classification of Danxia landscape. The Upper Cretaceous continental red beds in the Danxia Basin consist of the Changba and Danxia formations. The Changba Formation has a larger outcrop area, forming gentle low hills, while the Danxia Formation is concentrated and characterized by well development of cliffs, representing the typical Danxia landscape. The Danxia Formation is composed of coarse clastic rocks of alluvial fans and eolian sandstones, and is featured by having great thickness, tight cementation, high density and hardness, and being resistant to weathering. In contrast, the Changba Formation consists dominantly of fine-grained muddy clastic rocks deposited in river and lake environments, which are less resistant to weathering and cannot support Danxia landscape with cliffs. The Himalayan tectonic movement likely caused the overall uplift of the Danxia Basin, which resulted in the formation of a series of NE-trending faults and NNE-, NW-, and nearly EW-trending joints. The fracture surfaces may have facilitated subsequent weathering and erosion, producing prominent cliffs, reticulated valleys, and peculiar peaks and rocks. The Danxiashan area is in a subtropical humid climate, where weathering, collapse, water erosion, and karst processes are the main landscape-shaping external forces. Accordingly, the genesis of Danxia landscape is classified into five categories, i.e., collapse-scour, collapse-accumulation, weathering-denudation, river erosion, and dissolution-sedimentation types. The cliff development is a key element of Danxia landscape, and the different combinations of cliff quantities and types formed hills and gorges. Based on these features, the morphological types of Danxia landscape in Danxia-shan are divided into six major categories and twenty-two specific types. This paper has theoretical significance and practical values because it provides a better understanding of the formation processes of Danxia landscape in humid climate, and foundational materials for construction of national park, scientific mountain, and geoscience study travel. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Development and Evolution Characteristics of Strike-slip Faults in Tarim Basin and Its Geological Significance: A Case Study of FⅠ17 Fault in Fuman Oilfield LIU Qiang, ZHANG Yintao, CHEN Shi, SONG Xingguo, Li Ting, KANG Pengfei, MA Xiaoping Geoscience    2023, 37 (05): 1123-1135.   DOI: 10.19657/j.geoscience.1000-8527.2023.058 Abstract （99）   HTML （15）    PDF（pc） （16110KB）（195）       Knowledge map    Save The strike-slip fault in the platform Tarim basin has the characteristics of “controlling reservoir, controlling reservoir and controlling wealth”, but because it is developed in ultra-deep layer and its activity intensity is low, the fine analysis and evolution characteristic analysis of the fault is the focus and challenge of the current research.To deepen the fine analysis process of strike-slip fault structure and explore the geological significance of fault activity, we took FⅠ17 fault as a case study.Based on the new high-precision 3D seismic data in the Fuman oilfield, combined with a variety of seismic attributes such as coherence, maximum likelihood and reservoir amplitude change rate, we analyzed the spatial distribution regularity, activity characteristics and evolution process of faults, and the characteristics of fault control and storage in combination with the reservoir development characteristics.Based on the reconstruction of the local structural characteristics of the Precambrian basement, the development mechanism of fault plane strike migration is preliminarily analyzed.The results show that the local FⅠ17 fault plane has changed many times and its strike shifted counterclockwise from south to north.Based on the changing characteristics of the fault strike, the fault can be divided into three segments: North (NE8°), middle (NE33°) and south (NE50°).The fault has the characteristics of vertical delamination defor-mation.According to the fault deformation characteristics, it can be divided into the deep structural deformation layer characterized by vertical strike-slip (below TO3t), and the shallow structural deformation layer with echelon normal fault (above TO3t).The fault has the characteristic of “stratified flowering” in the deep structural deformation layer, and several flower-like structures are developed vertically, which are mainly distributed near the bottom of the Upper Cambrian (T∈3) and the top of the Yijianfang Formation (TO3t).Three groups of echelon normal faults are developed vertically in the shallow structural layer, which are distributed in TO3t-TS, TS-TC and TC-TT from bottom to top.The fault evolution is likely multi-stage, and the evolution can be divided into five stages: early Caledonian, middle Caledonian Ⅰ, middle Caledonian Ⅲ, late Caledonian-early Hercynian, and middle-late Hercynian.The Precambrian basement rift structure likely affected the development and connection of the overlying strike-slip faults, resulting in the fault plane offset. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Progress on Metallogenic Research of Granite-related Uranium Deposits from Luzong Ore District in the Middle and Lower Reaches of Yangtze River Metallogenic Belt ZHANG Shu, ZHANG Zanzan, HU Zhaoqi, SHI Lisheng, ZHOU Taofa, WU Ming'an, DU Jianguo Geoscience    2023, 37 (06): 1435-1448.   DOI: 10.19657/j.geoscience.1000-8527.2023.083 Abstract （81）   HTML （8）    PDF（pc） （12524KB）（178）       Knowledge map    Save The Lujiang-Zongyang ore district is one of the most important ore cluster regiones in the Middle and Lower Reaches of the Yangtze River Metallogenic Belt, and is also an important uranium prospecting area in the South China Uranium Province.Systematic uranium metallogenic study would benefit the understanding of the regional metallogenic theory and uranium prospecting.In this paper, we provide a review of the geological features, uranium-bearing intrusions, magmatic and metallogenic ages, ore-forming fluids, and uranium sources of the typical uranium deposits in the Lujiang-Zongyang ore district.The uranium deposits along the NE-trending A-type granite belt are controlled by intrusive contact, faults, and interlayer structures.The uranium deposits were formed at 114-108 Ma, whereas the ore-bearing granites are A1-type and were formed at 127-123 Ma with 115-110 Ma alkali feldspar granitic stocks.The ore-forming materials were derived from the ore-bearing intrusions and wall-rocks.The ore-forming fluids were the mixture of magmatic water and meteoric water.The uranium was likely originated from the leaching of the ore-bearing intrusions during the fluid circulation, and deposited by changes in the physicochemical condition.The uranium mineralization in the Luzong basin was controlled by concealed syenite and was formed at 131-129 Ma.The ore-bearing intrusions, which provide the ore-material sources, are of shoshonitic and were formed at 131 Ma.The ore-forming fluids were mainly of magmatic water.The uranium was probably fractionated from the F-B-rich melt into the magmatic fluids, and uraniferous veins were formed as the pressure and/or temperature dropped.We suggest that the granite uranium fertility indicator, high-precision dating of uranium deposits, and the genetic link between mantle-derived material and uranium mineralization are important research topics in future. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Sedimentary Environment of the Phosphorus-bearing Layers and Its Phosphate Enrichment Mechanism of the Cambrian Xinji Formation, Western Henan JIA Bingling, ZHANG Biyun, TANG Bin, ZHENG Deshun Geoscience    2023, 37 (04): 858-869.   DOI: 10.19657/j.geoscience.1000-8527.2022.094 Abstract （123）   HTML （16）    PDF（pc） （10935KB）（174）       Knowledge map    Save The Cambrian is an important period for global phosphate deposition, and the Cambrian Xinji Formation is an important phosphorus-bearing sequence on the southern margin of North China Craton. However, the relationship between the phosphorus-bearing stratigraphy and the sedimentary environment is poorly understood, and the phosphate enrichment mechanism needs to be further studied. Here, we studied the middle Xinji Formation at Baofeng, which contains a typical phosphorus-bearing layer. Field observations and laboratory analyses were conducted to reveal its depositional environment and explore its phosphorus source and enrichment mechanism. The results show that phosphorus nodules from the Xinji Formation are black, irregular flat disk-shaped, with size of 2 to 20 mm, and are distributed in the fine sandstone beds. Collophanite is the main mineral in the nodules. There are two forms: (1) cryptocrystalline rounded colloidal phosphorite with no internal structure and locally cracked; (2) microcrystalline oolitic colloidal phosphorite with fine veins. The depositional environment of the Xinji Formation was likely littoral-shallow marine transition. Phosphorus was likely derived from deep oceanic phosphorus-rich water and small shell biological activities. Formation of the phosphorus nodules was likely dominated by chemical deposition with indirect biological involvement. It has undergone syn-deposition and early diagenesis stages, and large amounts of phosphorus nodules were deposited in turbulent shallow water. Compared with the Cambrian phosphorus-bearing facies in the Yangtze Craton, the phosphate-bearing stratigraphy is clearly diachronic, and phosphate deposition occurred after the sedimentary hiatus. Initial deposition of the Cambrian phosphate was dominated by biological and chemical processes, and then the depositional environment and paleotectonics controlled the phosphorus-bearing stratigraphy and promoted the re-enrichment. We point out the relationship between phosphorus enrichment and the Early Cambrian sedimentary environment in the southern North China Craton, and provide abundant data for studying large-scale phosphate deposition. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Value and Excavation of Geological Culture: Taking Ahetan Geological Culture Village in Hualong County, Qinghai Province as An Example WANG Yifan, ZHANG Xujiao, ZHANG Xiangge, LI Junlei, YUAN Xiaoning, WANG Kaiya, LIU Xinlan, WANG Chongge, RAO Haoshu, LIU Jiang, QIN Yuan Geoscience    2023, 37 (05): 1423-1434.   DOI: 10.19657/j.geoscience.1000-8527.2023.114 Abstract （98）   HTML （7）    PDF（pc） （16575KB）（169）       Knowledge map    Save The construction of geological culture villages is in full swing across the country. However, its theoretical basis is not very clear, and especially most villages’ geological culture has not been fully excavated and demonstrated. Therefore, the excavation of geological culture becomes an urgent problem to be solved in the construction of geological culture villages. In 2022, Ahetan Geological Culture Village was awarded the first three-star geological culture villages in Yellow River Basin and Qinghai Province. It has made beneficial attempts and obtained good effects on geological culture excavation and three-dimensional expansion of rural culture revitalization. Based on the investigation and evaluation of heritages in Ahetan, including Yellow River terraces, ancient springs, ancient city, hollow elm tree, etc., and the in-depth excavation of geological culture, this paper systematically summarizes the definition, value, and excavation method of geological culture, and proposes it should be the theoretical basis of the construction of geological culture villages. Geological culture is all the material and spiritual wealth formed by human beings in the process of understanding, adapting, utilizing, and reforming the earth. The excavation of geological culture should focus on the close connection between geological processes and human civilization, reconstructing the history of geological processes and the harmonious relationship between humans and the planet, and demonstrating it to the public by commentary system. Through systematic summarization of geological culture and its excavation method, this paper aims to provide references for the construction and development of geological culture villages across the country. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Structural Characteristics of Strike-Slip Fault and Its Control on Fluid Distribution in the East Ⅱ Block of the Sulige Gas Field, Ordos Basin SONG Qing, SUN Panke, XIANG Jinyuan, TIAN Fajin, LÜ Fengqing, JIA Langbo, JIANG Shiyi, SHEN Yuhao, XU Huaimin, ZHANG Lin, HE Taihong, FANG Xiangyang Geoscience    2023, 37 (05): 1110-1122.   DOI: 10.19657/j.geoscience.1000-8527.2023.045 Abstract （81）   HTML （6）    PDF（pc） （13291KB）（163）       Knowledge map    Save Due to the complex structure of strike-slip faults in the East Ⅱ Block of the Sulige Gas Field in Ordos Basin, the fluid differential enrichment regularity and distribution characteristics under fault control are unclear, which hamper the optimization and development adjustment of favorable target of the local target layer.To resolve the above problems, based on the fine geological interpretation of seismic data, the fault structural analysis was carried out in this study.The staging characteristics of faults and their differential control effect on fluid distribution were defined.The results show that: (1) The local strike-slip faults have two types of 5 type section structural styles,i.e. single fault type and combination type, and five types of plane structural styles, are combined on the plane i.e.linear, oblique, overlapping, feathered and braidedtypes, (2) The strike-slip fault experienced three stages of tectonic evolution: Caledonian-early Yanshanian extrusion, middle and late Yanshanian strike-slip, and Himalayan extension.From deep to shallow strata, the fault structure underwent the evolution of single fault-type, flower-like, and Yanshanian-type.According to the different fault structural styles, three segment of linear shear segment, derived shear segment and mixed shear segment are developed from west to east. (3) Faults with different structural styles control different fluid differential enrichment modes.Four types of fluid differential enrichment modes are developed in the study area, namely the single-fault-closed-stable production rise type, assembly-open and low-yield rapid decline type, and shear-semi-open and low-yield slow decline type.Among them, the single-fault-closed-stable production rising type and the drawing-semi-open and high-yield slow decline type have higher daily gas production and cumulative gas production and stable production, which are the main local natural gas enrichment area.Our results reveal the important controlling effect of strike-slip fault on fluid differential enrichment in tight sandstone reservoirs, and point out the direction for local further development and adjustment. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Sedimentary Characteristics of Late Quaternary Loess in Hexigten Global Geopark and Its Paleoclimatic Implications LIU Xiaohong Geoscience    2023, 37 (03): 821-833.   DOI: 10.19657/j.geoscience.1000-8527.2023.071 Abstract （214）   HTML （17）    PDF（pc） （12425KB）（161）       Knowledge map    Save Loess has various paleoclimatic indicators, among which the particle size and magnetic susceptibility are important objects for paleoclimate research, and detailed studies on loess layers in different regions can faci-litate global climate change comparison and climate cycle division. Taking the Holocene Sanyixiang loess profile and the Upper Pleistocene Tuchengzi loess profile of Hexigten Global Geopark as an example, the loess samples were subjected to 14C dating, photoluminescence dating, grain size and magnetic susceptibility analyses. The regional paleoenvironmental change since the Late Quaternary was reconstructed, which provided a new and strong evidence for studying the climate types in northern China. The 14C dating on the Sanyixiang profile yielded 2.32 ka, 9.05 ka, 9.94 ka and 11.27 ka, whilst the OSL dating on the Tuchengzi profile yielded 21.5 ka, 23.5 ka, 43.9 ka, 53.4 ka, which show that the Sanyixiang and Tuchengzi profiles are Late Quaternary. The Sanyixiang and Tuchengzi profiles are young and old, respectively, forming a relatively complete loess sequence. The study shows that coarse silt(16-63 μm) was a major course-size component in the loess-paleosol deposition, accounting for 61.45%-62.4%, followed by sand(>63 μm) and clay(<4 μm). Based on stratigraphic features and grain-size curve, the Hexigten area underwent cold-hot, dry-humid cycles and at least four summer monsoon intensifying events. The grain size and magnetic susceptibility records of the Sanyi-xiang/Tuchengzi loess profiles are basically similar to those of the Luochuan profile of the loess plateau, with coarser grain size and lower magnetic susceptibility during the glacial period. Meanwhile, the magnetic susceptibility of the interglacial or interglacial step increases significantly, and the grain size becomes significantly smaller, indicating that the paleoenvironmental evolution of the two places was controlled by the East Asian monsoon intensity in a glacial-interglacial timescale. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Genetic Mechanism of Antiformal Negative Flower Structure in the Doseo Depression, Southern Chad Basin ZHOU Xiaorong, CHEN Shi, ZHANG Xinshun, DING Baotong, SONG Xingguo, PAN Chuqi, PENG Zijun Geoscience    2023, 37 (05): 1146-1154.   DOI: 10.19657/j.geoscience.1000-8527.2023.007 Abstract （88）   HTML （6）    PDF（pc） （19929KB）（154）       Knowledge map    Save The Doseo depression in the South Chad Basin is an important petroliferous basin in the Central African Shear Zone.A new kind of flower structure composed of normal faults (termed antiformal negative flower structure), is developed on the ENE-WSW-trending strike-slip fault zone.The faults there exhibit an en echelon arrangement in plane view, and have characteristics of positive flower-like and negative flower-like structures in the seismic profile, which are shown as a flower structure of lower "synform" and upper "antiform" shape.According to the development characteristics of the faults and the regional stress evolution, combined with 2D and 3D seismic data interpretation, the Doseo depression is divided into five evolution stages by the balanced cross-section reconstruction technique.Based on the strike-slip displacement, we analyzed the genetic mechanism of the antiformal negative flower structure in the depression.We considered that it is the result of superposition of the ENE-WSW-trending basement normal fault in the middle part of the depression in the formation stage of negative flower structure in the Early Cretaceous transtension period, and the antiform formation stage in the Paleogene transpression reversal.The early transtension strength is much greater than the later transpression reversal strength, and the difference between the strike-slip displacement components of the two is 10 to 30 times.The difference in strength makes it mainly present the negative flower structural style composed of normal faults, and only the antiform style formed during the inversion period is superimposed. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics and Geological Significance of Geoheritage in the Arxan Global Geopark, Inner Mongolia WANG Lulin, ZHU Qingfeng Geoscience    2023, 37 (04): 1075-1088.   DOI: 10.19657/j.geoscience.1000-8527.2023.086 Abstract （110）   HTML （3）    PDF（pc） （7279KB）（152）       Knowledge map    Save The scientific classification and characterization of geoheritage is the premise and foundation of rational utilization and protection of geoheritage. The Arxan Global Geopark has distinctive and extremely rich geoheritage, which has high touristic value and geological research significance. In this paper, based on geolo-gical survey and evaluation of the geoheritage, we divided the geoheritage resource into two categories,i.e. geomorphological landscape and water landscape,and six landform/landscape types,i.e. volcanic, rock, fluvial, structural, and spring water,and 9 subcategories,i.e. volcanic formation, volcanic lava landform, volcanic lake, granite landform, fluvial erosion landform, fluvial accumulation landform, structural landform, hot spring, and scenic river sections, with 47 geosites in total. Among them, volcanic landforms and hot spring landscapes are of great significance in the comparative analysis of global geoheritage. Additionally, the authors analyzed the characteristics of various geoheritage and discussed the important geotouristic significance of the geoheritage in the Arxan Geo-park. Studies have shown that the geoheritage of Arxan Geopark have important scientific value in the fields of geomorphology, hydrogeology and geotourism. This provides a scientific basis for the protection of geoheritage and tourism route planning, and promotes the sustainable development of geoscience research, science popularization and geoscience tourism in the Arxan Geopark. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Genetic Mechanism of the “Yucheng-Type” High-Grade Skarn Iron Deposits ZHANG Zhaochong, WANG Huaihong, XIE Qiuhong, SHEN Lijun, ZHU Yuzhen, LÜ Yunhe, JIN Bowen Geoscience    2024, 38 (01): 1-12.   DOI: 10.19657/j.geoscience.1000-8527.2024.003 Abstract （73）   HTML （11）    PDF（pc） （16652KB）（152）       Knowledge map    Save The discovery of high-grade skarn iron deposits in the Qihe-Yucheng area of northwestern Shandong Province is a significant breakthrough for iron prospecting in China.It is expected to become another potential important base of high-grade iron ore resource in Shandong Province after Laiwu, Jinling, and Jinan areas.Unlike traditional skarn iron deposits hosted in the contact zone between intrusions and carbonate rocks, the Litun iron orebodies in the Qihe-Yucheng area are hosted in the Carboniferous-Permian coal-bearing strata.The high-grade iron orebodies have a sharp contact with the surrounding rocks, which have been changed to horns in a large range.We attribute the occurrence of the iron orebodies in the Carboniferous-Permian coal-bearing strata far from the contact zone to the extremely low thermal conductivity of the overlying coal rocks, which allow the hydrothermal fluid to maintain a high-temperature state and long-distance migration.The formation of the Litun iron deposit may be ascribed to the rapid precipitation of magnetite due to decreasing temperature and salinity caused by the mixing of high-temperature magmatic fluid and low-temperature meteoric water.In addition, strong albitization commonly occurs near ore bodies, leading to the loss of iron in the dioritic rocks, which lays an important material foundation for the exsolution of iron-rich fluids and the formation of high-grade iron ores.Finally, we propose that the mantle-derived “highly differentiated” diorite and hypabyssal emplacement is favor for the exsolution of magmatic fluids, and is also prerequisites for the formation of the Hanxing-type iron deposit. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Soil Heavy Metal Pollution and Potential Risk Assessment Based on Different Ways of Land Use: A Case Study of Integrated Protection and Restoration Project of Mountains, Rivers, Forests, Fields, Lakes, Grass and Sand in the Liaohe River Basin (Huntai River System) LI Nan, CAO Mingjie, HAO Zhe, HOU Yongli, CHEN Hongdan, ZHANG Ying Geoscience    2023, 37 (06): 1655-1664.   DOI: 10.19657/j.geoscience.1000-8527.2023.034 Abstract （38）   HTML （2）    PDF（pc） （3724KB）（151）       Knowledge map    Save In the project “Liaohe River Basin (Huntai River system) mountain, water, forest, farmland, lake, grass and sand integrated protection and restoration project”, basing on soil monitoring data of construction land and agricultural land in restoration area of upper reaches of Huntai River system, we established a soil heavy metal pollution assessment system.The system integrates correlation analysis, single factor index, compound index, potential ecological risk index, and the inverse distance weight interpolation method.The results show that the elements including arsenic, mercury, lead, nickel, cadmium and zinc in agricultural land have similar pollution source, while arsenic, mercury and lead in construction land have similar pollution source.Soil environmental quality was comprehensively assessed by combining the single factor index and composite index.Agricultural land contains cadmium, copper, nickel, zinc and chromium pollution, while construction land has only lead pollution.Ranking of heavy metal pollution area shows chromium>lead>copper>zinc>nickel>cadmium; Ranking of composite pollution type area shows pollution-free>single-element pollution>two-element pollution>three-element pollution. Composite level area ranking shows clean>alert>light pollution.According to the potential ecological risk index, the potential ecological risk levels of single heavy metal on construction land and agricultural land are determined to be of minor hazard level.The comprehensive potential ecological risk index of construction land is 2.13 to 15.23, and that of agricultural land is 5.79 to 41.99, both are within the minor ecological hazard range.Our results can accurately determine the type, location and area of heavy metal pollution, which can provide a basis for soil environmental control in the upper reaches of Huntai River system, and the established research system can also provide references for soil environmental assessment in other basins. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Evaluation of Geological Disaster in Chengde Area Based on GIS and AHP Coupling Technology WANG Ruifeng, ZHAI Yanliang, ZHANG Baojun, SHEN Guoqiang, ZENG Yifan Geoscience    2023, 37 (04): 1023-1032.   DOI: 10.19657/j.geoscience.1000-8527.2021.160 Abstract （79）   HTML （3）    PDF（pc） （11041KB）（151）       Knowledge map    Save To evaluate the impact of geological disasters, this study selected the Chengde area of Hebei Province as an example. Firstly, we used AHP and ArcGIS to evaluate the susceptibility of geological disaster. Secondly, the geological disaster bearing body vulnerability was established based on the current local land use. Finally, based on the constructing the judgment matrix, the geological disaster impact evaluation was established by overlaying the geological disaster susceptibility zoning map on the geological disaster vulnerability zoning map. The results show that the high-impact and relatively high-impact areas of geological disasters are mainly distributed in the north of Kuancheng county, east of Xinglong county, and south of Pingquan city. The medium-impact areas are mainly distributed in the central and southern parts of Luanping county, the south of Xinglong county, the central and northern parts of Pingquan city, the south of Shuangqiao district, and the south of Shuangluan district. The low-impact and relatively low-impact areas are mainly distributed in the north of Chengde, Longhua, Fengning and Weichang counties. This study comprehensively considers the dual attributes of geological disasters, and accurately evaluates the geological disaster susceptibility and the vulnerability of geological disaster bearing body in different combination states. The evaluation results can effectively avoid the problem of geological disaster prevention and control planning based on the geological disaster vulnerability. In addition, the evaluation results can provide scientific basis and technical guidance for geological disaster prevention and control planning in Chengde area. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Differential Deformation and Evolution Characteristics of the No.17 Strike-slip Fault Zone in the Tarim Basin WANG Qinghua Geoscience    2023, 37 (05): 1136-1145.   DOI: 10.19657/j.geoscience.1000-8527.2022.090 Abstract （86）   HTML （8）    PDF（pc） （8564KB）（148）       Knowledge map    Save The No.17 strike-slip fault zone in Tarim Basin is a large strike-slip fault zone that runs through the transitional zone between the Tazhong Uplift and the Afghani Manchu area.A series of important breakthroughs have been made in oil and gas exploration along this fault zone in recent years.Based on the new 3D seismic data in Fuman oilfield, we analyze the spatial structure and evolution processes of the northern segment of the No.17 strike-slip fault zone, and discuss the relationship between the spatial structure and oil properties.The results show that the No.17 strike-slip fault zone has stratified deformation characteristics in the profile.The fault zone in the Cambrian subsalt structural layer is straight into the basement, a few branch faults are deve-loped in the Middle Cambrian salt structural layer, and the Upper Cambrian-Middle Ordovician carbonate structural layer has strong fault activity and a large deformation range.In the Upper Ordovician-Carboniferous clastic structural layer, normal faults are developed.On plane view, the northern section of the No.17 strike-slip fault zone has variable strike direction, which can be subdivided into the north, middle and south subsections.The north subsection has long linear fault extension, the middle subsection has obvious fault overlapping characteristics, and the south subsection has a braided structure.Under the top surface of Middle Ordovician limestone, the faults are mainly linear extending, while on the top surface of Silurian, they are in an echelon pattern.The No.17 strike-slip fault zone has sinistral strike-slip activity in the Middle Ordovician and Late Ordovician-Carboniferous, and the activity intensity is strong in the north and weak in the south.According to the fault deformation and regional stress field characteristics, the evolution of the fault zone can be divided into the early Caledonian fault initial development stage, the middle Caledonian fault mature stage, and the late Caledonian-Hercynian demise stage. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Development Model of Microbial Reef-shoal in the Lower Cambrian Xiaoerbulak Formation Under Transgression-Regression Transition in the Northern Tarim Basin CHEN Gege, GAO Zhiqian, JIAO Cunli, HU Zongquan, YUAN Yuxuan, WEI Duan, ZHAI Xinqing, CHANG Zhe Geoscience    2023, 37 (05): 1169-1181.   DOI: 10.19657/j.geoscience.1000-8527.2022.093 Abstract （58）   HTML （3）    PDF（pc） （22205KB）（146）       Knowledge map    Save Based on the outcrop observation in Aksu area in the northwestern Tarim Basin, and the analysis of logging data and thin section identification of key exploration wells there, the high-precision sequence stratigraphic framework at north Tarim Basin is established.We analyzed the development model of microbial reef-shoal and carbonate platform evolution in the Xiaoerbulak period, and suggested that the Xiaoerbulak Formation can be subdivided into two third-order sequences (SQ1 and SQ2) and five fourth-order sequences (sq1, sq2, sq3, sq4 and sq5): sq1 and sq2 developed layered microbial mats, which were middle-inner ramp deposition, corresponding to the ramp carbonate platform stage; sq3 is a transition period from ramp carbonate platform to slightly rimmed shelf carbonate platform, and the relative sea-level likely rose first and then fell, and microorganisms began to build reefs in the paleo-geomorphic highlands, and the microbiolites were basically undeveloped in the slope area of low paleo-geomorphic terrain; sq4 and sq5 represent the stage of slightly rimmed shelf carbonate platform with continuous sea-level decline; sq4 developed algal grain shoal and microbial reef deposits, whilst sq5 developed sand shoal, gravel shoal and microbial reef deposits.The high-precision sequence stratigraphic correlation shows that the sea-level change controlled the vertical development of microbial reef shoal, and the paleo-geomorphology controlled the planar microbial reef shoal distribution. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Multi-Source Remote Sensing Recognition of Reactivation Characteristics of An Ancient Landslide Group at Taipingqiao in the Dadu River Catchment, Eastern Tibetan Plateau ZENG Shuai, MA Zhigang, ZHAO Cong, YANG Lei, ZHANG Su, DONG Jihong, LIANG Jingtao, YAN Shengwu Geoscience    2023, 37 (04): 994-1003.   DOI: 10.19657/j.geoscience.1000-8527.2023.060 Abstract （73）   HTML （4）    PDF（pc） （15890KB）（141）       Knowledge map    Save The Dadu River catchment in the eastern Tibetan Plateau is one of the most developed areas of ancient landslides in the world. Due to the increasing human engineering activities and the frequent heavy rainfall occurrence, the problem of ancient landslide resurrection in the Dadu River catchment has become increasingly serious. In this study, we selected the ancient landslide group at Taipingqiao county, and used multi-source remote sensing technology of Unmanned Aerial Remote Sensing (UAV) and Interferometric Synthetic Aperture Radar (InSAR) monitoring to analyze the resurgence deformation characteristics and mechanism of the landslide in the Gulozhai village. Based on the UAV aerial remote sensing images, the landslide deformation characteristics at Gulozhai can be clearly identified. Two sets of large tensional cracks extend horizontally through the upper and middle landslide bodies, and the large secondary landslide on the left of the leading edge indicate that the landslide shows overall resurgence signs. Based on the InSAR time-series monitoring results, we confirmed that the two-month heavy rainfall from May to June 2020 was the main trigger for the resurrection of the ancient landslide, which is still in continuous deformation. Under heavy rainfall or earthquake, the secondary landslide on the left of the leading edge may slide further and even trigger the overall slope destabilization and sliding in the Luozhai village. Our results on the deformation characteristics and mechanism of the landslide resurrection at Gulozhai based on multi-source remote sensing technology can provide effective technical support for disaster prevention and mitigation related to the resurrection of ancient landslides in the Dadu River catchment. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Vegetation Dynamics and Driving Factors in Zhangjiakou-Chengde Area of Hebei Province from 2001 to 2020 WANG Qian, JIN Xiaomei, ZHANG Xucai, YIN Xiulan, JIN Aifang, LUO Xufu Geoscience    2023, 37 (04): 881-891.   DOI: 10.19657/j.geoscience.1000-8527.2023.028 Abstract （101）   HTML （5）    PDF（pc） （8786KB）（140）       Knowledge map    Save As a water conservation function area in the Beijing-Tianjin-Hebei region, the vegetation dynamics of Zhangjiakou-Chengde (Zhang-Cheng) area is of great significance for the ecological/environmental construction and protection. Based on MODIS-NDVI, temperature and precipitation, land use, groundwater depth and measured soil moisture data, Sen+Mann-Kendall trend analysis, partial correlation analysis and other methods, we analyze the spatial-temporal variation characteristics of vegetation and the response characteristics of temperature and precipitation, land use, groundwater depth and soil moisture in Zhang-Cheng area from 2001 to 2020. The results show that the annual mean NDVI value shows an upward fluctuation trend. The vegetation coverage is characterized by being low in the northwest and high in the southeast. Significant vegetation improvement areas were mainly distributed across most of Baxia, accounting for 85.79% of the study area. There are positive correlations between precipitation, temperature, and the vegetation index. Furthermore, the vegetation variation agrees well with the land-use change. The vegetation growth is best when the groundwater depth is around 6.2 m. The spatial distribution of soil moisture is low at Bashang and high at Baxia. The NDVI increases with increasing measured soil moisture. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Zircon U-Pb Isotopic Geochronology,Bulk Geochemistry and Their Geological Significance of the Quartz Monzodiorite from the Taibaihe Region in the South Qinling Orogen WANG Ruiting, LI Qingfeng, QIN Xishe, ZHANG Bin, WANG Bowen, JI Yuefei Geoscience    2023, 37 (03): 562-572.   DOI: 10.19657/j.geoscience.1000-8527.2023.013 Abstract （101）   HTML （19）    PDF（pc） （7090KB）（140）       Knowledge map    Save In order to ascertain the formation time, petrogenesis, magma source and tectonic setting of the intermediate rocks in Taibaihe area of South Qinling, zircon U-Pb geochronology and geochemistry of the quartz monzodiorite have been studied in the thesis. The results of LA-ICP-MS zircon U-Pb gechronology show that the 206Pb/238U weighted mean age of quartz monzodioirte is (216.8±2.2) Ma (MSWD=1.15,n=20), indicating that it was formed in the Late Triassic. According to the lithogeochemistry studies, the quartz monzodioirte belongs to the aluminum unsaturate and high potassium calc-alkaline series. This suite of rocks are rich in LILE (such as K, Rb) and HFSE (such as Zr, Hf), and relatively depleted in Nb, Ta, P, and Ti. The quartz monzodiorite is rich in LREE and poor in HREE, with slightly negative Eu anomalies. The magma source has the characteristics of crust-mantle mixed molten. Based on the tectonic evolution of the South Qinling Orogen, we consider that the Taibaihe quartz monzodioirte may be formed in the syn-collisional to post-collisional stage of the orogeny, belonging to the product of same homologous magmatism activity as Xiba granites. According to the previous studies of regional magmatism, tectonic activity and mineralization, and the new work of magmatic-metallogenic ages modification in our study, it is considered that the metallogenic age of Fengtai ore cluster region is Late Triassic. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Lithofacies Characteristics and Sedimentary Model of the Lower Cambrian Shale in the Northeastern Margin of Tarim Basin LIU Wangwei, LI Yifan, GAO Zhiqian, FAN Tailiang, ZHANG Tan, KUANG Mingzhi Geoscience    2023, 37 (05): 1155-1168.   DOI: 10.19657/j.geoscience.1000-8527.2023.006 Abstract （94）   HTML （2）    PDF（pc） （17719KB）（138）       Knowledge map    Save The study of shale facies characteristics and sedimentary model can help to reveal the characteristics and distribution of fine-grained source rocks.The lithofacies assemblage and sedimentary model of the Lower Cambrian shale in the northeastern margin of the Tarim Basin are analyzed by means of outcrop description, thin-section petrographic observation and organic matter content measurement.The sea-level of the Lower Cambrian in northeastern Tarim Basin was characterized by rapid transgression, continuous deepening and rapid shallowing.The sea-level change may have directly affected the shale development.Six lithofacies and three lithofacies assemblages are developed from bottom to top in the Lower Cambrian in the study area: (1)the semi deep-water shelf lithofacies assemblage includes siliceous shale facies, siliceous clay-shale mixed facies and phosphorous shale facies; (2)the deep-water shelf lithofacies assemblage includes siliceous shale facies and clayey shale facies; (3)the shallow water shelf lithofacies assemblage includes calcareous shale facies and siliceous calcareous shale facies.In the Early Cambrian, the northeastern Tarim region was likely in a semi-deep-water shelf environment, with strong extension and frequent hydrothermal activity.The hydrothermal activity has a dual role in the enrichment of organic matter, which is not conducive to organic matter enrichment in the siliceous shale in the semi-deep-water shelf environment, and to the organic matter enrichment in the phosphorous shale in the semi-deep-water shelf environment.With the continuous sea-level rise, tectonic activity and hydrothermal activity decreased, and the deep-water shelf lithofacies assemblages began to develop.During this period, the organic matter was well preserved.The sedimentation rate was slow, and the paleoproductivity was high.The total organic carbon (TOC) content in the shale was relatively high.During the sedimentation of the Xidashan Formation, the environment was generally of shallow water shelf.During this period, the content of silicic minerals in the sediments decreased, while that of calcareous minerals increased.The preservation conditions of organic matter were poor, the sedimentation rate was high, and the TOC content in the shale was relatively low.We considered that Lower Cambrian phosphorous shale facies and the deep-water shelf lithofacies assemblage in the northeastern Tarim basin represent favorable intervals. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Ecological Vulnerability Evaluation and Countermeasures of Ecological Restoration in Ecological Restoration Areas of Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands,Tai’an City XU Fei, JIAO Yuguo, TANG Liwei, WEI Kai, YIN Yanpeng, HU Qingling, ZHAI Daiting, ZHAO Xinchu Geoscience    2023, 37 (04): 892-902.   DOI: 10.19657/j.geoscience.1000-8527.2021.152 Abstract （89）   HTML （8）    PDF（pc） （3047KB）（135）       Knowledge map    Save Ecological protection and restoration has become a core content for the construction of ecological civilization in China. The study of ecological vulnerability is an important basis for evaluating ecological environmental problems, and for performing ecological protection and restoration. To scientifically identify the formation mechanism and ecosystem vulnerability variation in the ecological restoration area of mountains-rivers-forests-farmlands-lakes-grasslands in Tai’an City, and to clarify the direction of ecological protection and restoration, we used the pressure state response (PSR) framework model to evaluate the local ecological vulnerability. We further diagnosed the ecological environment problems in combination with the evaluation results, thus put forward countermeasures for ecological protection and restoration. The results show that the low vulnerability areas account for the highest proportion (37.97%), indicating that the overall local ecosystem is relatively stable. Among the investigated counties, cities and districts, there is higher proportion of vulnerability areas in the Taishan (48.77%) and Daiyue (37.15%) districts and Feicheng (30.97%) city, indicating that the ecosystem of the three counties is unstable. Considering the local situation, we put forward five ecological restoration suggestions, including (1) promote mine ecological restoration, (2) improve forest and grass coverage, (3) comprehensively regulate the watershed system, (4) increase biodiversity and improve ecological security system. The evaluation results and the proposed ecological restoration countermeasures are helpful to the rational layout of the project. It can also facilitate the targeted planning of the construction of ecological civilization in the implementation of the local ecological protection and restoration project of mountains-rivers-forests-farmlands-lakes-grasslands, and provide reference for the implementation of the ecological restoration project of mountains-rivers-forests-farmlands-lakes-grasslands in China. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Influence of Geological Formation on the Ecological Spatial Pattern of Soil and Vegetation in the Danjiang River Source Region QIAN Xinyu, BIAN Xiaowei, ZHANG Yafeng, WANG Yingwei, YANG Yunjun, YOU Jun Geoscience    2023, 37 (04): 903-913.   DOI: 10.19657/j.geoscience.1000-8527.2023.004 Abstract （72）   HTML （6）    PDF（pc） （11545KB）（133）       Knowledge map    Save To explore the major factors affecting the ecological spatial pattern of soil and vegetation in the Danjiang River source region, and support the ecological management of the basin, we analyze the contributions of different geological formations on the soil properties and vegetation coverage. The study encompasses the aspects of the type, nutrient content and joint by combining GIS, RS and elemental geochemical analysis methods. Soil texture, physical and chemical properties, and nutrient element content in soil and vegetation have clear correlations with the rock type, and the joint development has a significant impact on forest type and vegetation coverage. The joint density of the Paleozoic mafic volcanic rock and mafic magmatic rock formation, the Triassic and Precambrian felsic magmatic rock formation is over 4 m/m2. The occurrence is steep, and the content of P and other nutrient elements is high, which is conducive to the growth of deep-rooted trees. The joint density of the Precambrian clastic rock formation and the Paleozoic felsic magmatic rock formation is 3-4 m/m2, and the occurrence is relatively slow. Thus, the forest type is dominated by thickets, and minor Pinus tabulaeformis grows on the slope top. The Cretaceous-Paleogene clastic rock formation is mainly composed of glutenite and mudstone interbeds, with the joint density below 1 m/m2 and poor penetration, i.e., the forest type is a small number of low shrubs. The formation type plays a vital role in controlling soil properties and ecological vegetation patterns, providing the scientific basis for local governments to implement land spatial zoning control based on geological construction. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geoscience    2023, 37 (05): 0-0.   Abstract （81）      PDF（pc） （5406KB）（132）       Knowledge map    Save Related Articles | Metrics | Comments（0）

Select

Middle Late-Pleistocene Sporopollen Records of Ake River III Terrace in Southern Margin of Aba Basin, Western Sichuan ZHU Ting, HE Zhengwei, YANG Zhenjing, KANG Guichuan, GUAN Sensen, ZHU Yuting Geoscience    2023, 37 (04): 870-880.   DOI: 10.19657/j.geoscience.1000-8527.2022.037 Abstract （99）   HTML （8）    PDF（pc） （6369KB）（131）       Knowledge map    Save Vegetation growth and change have important implications for climatic evolution. In this study, we used sporopollen record to reconstruct paleovegetation and paleoclimate. Based on the sporopollen study of the Ake River III-level terrace in the southern margin of Aba basin in western Sichuan (eastern Qinghai-Tibet Pla-teau)and OSL dating, the results show that PM01 is (78.4±7.1) to (71.6±6.2) ka B.P. (middle Late Pleistocene). According to the palynological assemblage and mathematical analysis, the PM01 profile was divi-ded into three palynological zones. The results show that vegetation in the Aba Basin was sparse forest and grassland from (78.4±7.1) to (71.6±6.2) ka B.P. in the middle Late Pleistocene. The paleoclimate evolution can be divided into three stages: (1) cold and arid; (2)warmer than the first stage, but still cold and dry; (3)warmer and then cooler and drier. The results are consistent with the climate evolution trend of the last ice age, and provide new data for the study of the Quaternary regional vegetation and climate evolution, which is of great significance for studying Quaternary paleoclimate in the eastern Qinghai-Tibetan Plateau. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Regional Geochemical Data Analysis Using Isometric Log-ratio Transformation and Mixture Distribution LI Zhu, ZHANG Dehui, YANG Fan, LIU Xiangchong Geoscience    2023, 37 (03): 662-673.   DOI: 10.19657/j.geoscience.1000-8527.2023.009 Abstract （118）   HTML （9）    PDF（pc） （12589KB）（129）       Knowledge map    Save Regional geochemical exploration data are typical compositional data. Isometric log-ratio transformation (ILR) produces an orthonormal basis of geochemical data, which can eliminate the data closure effect and account for the data compositional nature. However, it is still difficult to interpret ILR-transformed variables. To make ILR transformations easier to understand, geological knowledge and data-driven methods are used to construct the interpretable ILR-transformed variables. This method was applied to extract geo-information from stream sediment geochemical data in the central and southern Da Hinggan Mountains, Inner Mongolia, northern China. Based on these geological information and hierarchical cluster analysis, sequential binary partition was constructed among the Sn, W, Cr, and Ni concentrations, and expressed as variables b1, b2 and b3 by ILR transformation. Furthermore, the expectation-maximization (EM) algorithm modified by a minimum message length criterion (MML) was employed to investigate the variables mixture distributions.The ILR-transformed variables follow either a bi-normal or tri-normal distribution, which were interpreted as fingerprints inherited from mafic magmatic, Sn-W hydrothermal, and later geological processes. The high-average subpopulation of b1, b2 and b3 variables of ILR transformation corresponds to the anomalies of W-Sn metallogenic system, and four areas were predicted to have high Sn-W prospecting potential. This study shows that the ILR transformation and MML-EM algorithm are promising tools to effectively extract geo-information from geochemical data and delineate anomalies. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

New Perspectives of the Features, Formation, and Evolution of the Special Danxia Landscape in Chenzhou, Hunan HUANG Leqing, WU Chihua, ZHOU Liyun, JIN Ni, PENG Shiliang, HU Nengyong, YANG Changming, CHEN Jie Geoscience    2023, 37 (06): 1680-1694.   DOI: 10.19657/j.geoscience.1000-8527.2023.118 Abstract （47）   HTML （13）    PDF（pc） （21126KB）（126）       Knowledge map    Save The Feitianshan-Gaoyiling area in Chenzhou (Hunan Province) is a prominent attraction in South China, known for its distinctive Danxia landform. Unlike typical Danxia landscapes, this area features distinct dome mounds. However, despite its social popularity and scientific value of its unique geomorphology, detailed studies on its geomorphological features, internal genetic mechanism, and evolution have long been overlooked. Through field investigations, we discovered that the Danxia landform in the Feitianshan-Gaoyiling area has seven geomorphological subtypes, including stone village, rock mound, Chibi, stone column, stone wall, cave, and linear trench. Notably, the eastern and western sides of the study area display distinct differences in the Danxia landscape. The eastern side is dominated by dome mounds and stone villages, where the structural strata comprise of eolian desert-facies sandstone, characterized by significant eolian sedimentary structures such as giant staggered bedding, small-scale granular flow layers, and corrugated layers. Meanwhile, the western side of the area features a “top slope, steep slope, foot gentle” peak forest-type Danxia landscape, primarily composed of alluvial fan massive conglomerates. The variations in lithofacies types between the eastern and western sides are the main factors contributing to the diverse geomorphological forms, developed through multistage tectonic transformation, water erosion, weathering, and collapse in the Himalayan period. Using the analysis of the area elevation integral model (HI), we determined that the local Danxia landform is in the early residual hill stage of old age. Accordingly, we propose a three-stage landscape model of “sedimentation pregnant landscape-tectonic uplift landscaping-surface force carving landscape”, to analyze the Danxia landform origin and enhance the brand connotation of Danxia scenic landforms. We aim to better understanding in the distinctive landscape of rock-like Danxia in the humid South China climatic region, and to provide scientific guidance and reference for the development and utilization of Cretaceous Danxia landform geological heritage in South China. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Depositional Environment and Sedimentary Model of the Fengcheng Formation in Mahu sag, Junggar Basin NI Minjie, ZHU Hexuan, HE Wenjun, YANG Sen, ZOU Yang, ZHANG Yuanyuan Geoscience    2023, 37 (05): 1194-1207.   DOI: 10.19657/j.geoscience.1000-8527.2023.061 Abstract （102）   HTML （6）    PDF（pc） （31168KB）（124）       Knowledge map    Save The Mahu sag is one of the most prolific oil-gas sags in the Junggar Basin.The Lower Permian Fengcheng Formation is the main high-quality lacustrine source rocks, and is considered as the key exploration target in the Mahu sag.The lithofacies distribution and sedimentary environment of the Fengcheng Formation are of great significance in studying the tectonic evolution and further oil-gas exploration of the Mahu sag.Based on the latest logging data, we established a comprehensive stratigraphic column for the Fengcheng Formation from well Maye 1, and clarified the lithofacies distribution of the Fengcheng Formation.The tectonic sedimentary environment and sedimentary model of the Fengcheng Formation are constructed subsequently.The Fengcheng Formation is mainly composed of dark fine-grained sedimentary rocks in well Maye 1, with a large number of soft-sediment deformation structures.The middle member of the Fengcheng Formation was likely deposited in (semi-)deep lacustrine facies.According to the lithofacies profile in the Fengcheng Formation, the cyclic characteristics of progradation-retrogradation-progradation developed from bottom to top, and the sedimentary facies changed from fan delta, lacustrine to river delta facies from southwest to northeast.Volcanism likely played a key role in the lower member of the Fengcheng Formation of shallow lacustrine facies in the northern part of Mahu sag.In the middle member of the Fengcheng Formation, the southern part of Mahu sag developed fan-delta deposits, which is transformed into delta-shore shallow lacustrine deposit to the west of Mahu sag, and semi-deep to deep lacustrine deposits are developed in the northern part.The middle member of (semi-)deep lacustrine facies is characterized with extensive distribution and abundant alkaline minerals in the depocenter.The chemical precipitation in the middle member of the Fengcheng Formation is the most widely distributed, indicating the maximum flooding surface.The progradation in the upper member of the Fengcheng Formation may have resulted from shrinking of the sag.Fan delta deposits are developed in the southern and western parts of the Mahu sag, and semi-deep lacustrine to shore-shallow lacustrine facies are developed in the northern part.Combined with its sedimentary evolution process, the Fengcheng Formation is likely deposited and multiple-sourced, including terrigenous clastic deposits, endogenous chemical precipitates and pyroclastic material. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Strontium in Soil-crop Migration and Enrichment Discussion on the Standard of Strontium Enrichment in Crops:A Case Study from the Shihe Area in Gushi, Henan WANG Dongxiao, YUAN Dezhi Geoscience    2023, 37 (03): 767-777.   DOI: 10.19657/j.geoscience.1000-8527.2023.024 Abstract （224）   HTML （4）    PDF（pc） （4917KB）（123）       Knowledge map    Save By systematically collecting and analyzing soil and crop samples in the Shihe river basin of Gushi (Henan Province), and conducting geochemical evaluation of land quality, we identified regional soil Sr geochemical characteristics, influencing factors, and migration and enrichment mechanisms in soil and crops, i.e., residue state>strongly organic bound state>ion-exchange state>ferromanganese oxidation state>humic acid bound state>carbonate bound state>water-soluble state account for 98%. Strontium exists primarily in the soil in an insoluble stable form. In a weakly acidic environment, the insoluble Sr-bearing minerals (SrSO4 and SrCO3) hydrate and hydrolyze to form water-soluble Sr(HCO3)2 and SrCl2, which are absorbed and utilized by plants to facilitate Sr migration in soil and crops. The Sr-rich standard for peanut, wheat, corn, rice, and other crops was proposed by comparing the Sr content of related crops (domestic and international), i.e., the lower limit is 0.65 mg/kg for Sr-rich rice, and 1.08 mg/kg for Sr-rich peanut, wheat, and corn. According to this Sr content standard, our wheat and peanut (and some rice) samples are Sr-rich. Our results provide a new reference for the development of Sr-rich land resource and Sr-rich agricultural products in the Shihe river basin. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Petrogenesis and Tectonic Implications of Granite Porphyry in the Beidashan Area,Alxa Block: Constraints from Geochemistry, Zircon U-Pb Geochronology and Hf Isotopes SU Hui, ZENG Renyu, GAN Debin, YAN Jie Geoscience    2023, 37 (06): 1580-1596.   DOI: 10.19657/j.geoscience.1000-8527.2023.063 Abstract （53）   HTML （13）    PDF（pc） （10994KB）（122）       Knowledge map    Save The Beidashan Complex is located in the Beidashan area of the Alxa block,and represents an Early Precambrian metamorphic basement.These magmatic-metamorphic events are of great significance for studying the tectonic evolution and tectonic affinity of the Early Precambrian Alxa block.Here,we studied the petrography,geochemistry,zircon geochronology and Hf isotopes of the Cijingzi granite porphyry in the Beidashan area.The geochemical data shows that Cijingzi granite porphyry is characterized by high SiO2(73.85%-75.41%),Al2O3(13.40%-14.19%) and K2O(3.83%-4.80%),and low Na2O(2.10%-3.31%) and $\mathrm{Fe}_{2} \mathrm{O}_{3}{ }^{\mathrm{T}}$(0.93%-1.33%).The rocks have obvious negative Eu anomalies(δEu=0.15-0.29),with obvious enrichment of light rare earth elements(LREE)and depletion in heavy rare earth elements(HREE)in the chondrite-normalized REE patterns.It is also depleted in Nb, Ta,Ti and other high field strength elements(HFSEs)in the primitive mantle-normalized trace element patterns,similar to highly fractional I-type granite.LA-ICP-MS zircon U-Pb dating of the Cijingzi granite porphyry yielded an emplacement age of 2,035.6±8.4 Ma.The Cijingzi granite porphyry has εHf(t)=0.48-7.04 and Hf model age=2,627-2,222 Ma,indicating that the characteristics of the mixing of crust-derived magmas with mantle-derived ones.Combined with the previous studies,the magmatic event at Ca.2.0 Ga in the Alxa block exhibits the bimodal volcanic assemblage,and the felsic rocks are mostly of A-type,which were formed in an extensional environment.Zircon ages and Hf isotope compositions shows that the Alxa block and the Khondalite belt of the North China Craton have clear affinity in the Paleoproterozoic. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geochronology and Geochemistry of the Intermediate-basic Dikes in the Beishan Area, Inner Mongolia: Implications for Tectonic Evolution of the Northern Margin of the Tarim Plate XUE Zhongkai, FAN Baocheng, HUANG Haoqing, TANG Weidong, GE Zhanlin, LI Pengwei, HU Jianhui, YANG Xiaoqi, GUO Yongchao, LI Kong Geoscience    2023, 37 (03): 627-644.   DOI: 10.19657/j.geoscience.1000-8527.2022.089 Abstract （95）   HTML （15）    PDF（pc） （13710KB）（121）       Knowledge map    Save The formation age and genesis of the altered intermediate bedrock dike in the Laodonggou gold depo-sit (Ejin Banner, northern margin of Tarim terrane) provide a window to study the gold mineralization constraints and the Paleo-Asian Ocean evolution. In this study, a series of gold ore-related diabase dike and altered diorite porphyrite dike samples were collected from the Laodonggou ore section II, on which we conducted LA-ICP-MS zircon U-Pb dating, Hf isotope and whole-rock geochemical analyses. The results showed that the emplacement of diabase dikes and diorite porphyrite dikes occurred in the Early Permian (286.5±1.7 Ma) and Middle Triassic (243.2±1.1 Ma), respectively, and such age sequence is consistent with the observed field crosscutting relationship. According to the characteristics of diorite porphyrite dikes interlaced with gold orebo-dies, the gold mineralization is suggested to be slightly after 243 Ma. Zircon εHf(t) value of the diabase dikes ranges from -3.67 to 0.97, and the whole-rock element composition shows that the rocks are peraluminous calc-alkaline. This indicates that the magma source region contains both Neoproterozoic juvenile crustal components and Mesoproterozoic ancient crustal components. Altered diorite porphyrite dike εHf(t)=-0.07 to -4.76, and the whole-rock element composition is the peraluminous K-rich basalt series (K-rich characteristics affected by the potassic alteration in the mining area), indicating that the magma is mainly derived from the Mesoproterozoic crustal melting. Based on the Late Paleozoic to Early Mesozoic tectonic evolution in the northern margin of the Tarim block, we proposed that the Late Carboniferous-Early Permian paleo-oceanic basin subduction in the Beishan region may have led to partial melting of the mantle wedge, and that the magma may have ascended into shallow faults and cooled to form diabase dikes. In the end Early Permian, the Beishan region entered an intracontinental tectonic stage, and post-orogenic extension occurred in the Middle Triassic. This likely resulted in the decompression and melting of Mesoproterozoic crustal materials, and magma emplacement along crustal faults to form diorite porphyrite dikes. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geochronological and Geochemical Characteristics of the Tianchitang Granodiorite in Southwestern Fujian Province: Indications for the Regional Metallogeny ZHOU Yan, FAN Feipeng, KANG Congxuan, ZHAO Xilin, XIAO Fan, XU Mincheng, SHEN Mangting, ZHU Yiping Geoscience    2023, 37 (06): 1467-1481.   DOI: 10.19657/j.geoscience.1000-8527.2023.001 Abstract （58）   HTML （11）    PDF（pc） （12911KB）（119）       Knowledge map    Save Granodiorite,emplaced at the transition of Early to Late Cretaceous,is the most important Cu-polymetallic metallogenic intrusion in southwestern Fujian province.The Tianchitang granodiorite,located in the transition zone between the Cretaceous Zijinshan volcanic basin and the Late Paleozoic SW Fujian depression,presents a Cu-Fe skarn affinity at the outer contact zone.LA-ICP-MS magmatic zircon U-Pb dating of the granodiorite has been conducted to understand the regional magmatic mineralization,yielding weighted average 206Pb /238U ages of (100.7±1.0) Ma and (99.6±0.7) Ma. The result indicate that the granodiorite was emplaced early Late Cretaceous.Petrogeochemistry shows the intrusion is metaluminous-peraluminous and high-K calc-alkaline.The rocks are enriched in LILEs(Rb,Th,Zr and Hf) and depleted in HFSEs(Nb,Ta,Sr,Ti and P) with a weak negative Eu anomaly.The comparison with ore-forming intrusions in the Zijinshan orefield indicates that all of these intrusions were simultaneously formed in an extensional tectonic setting,and were the products of mixing of the granitul magma by partial melting of crustal material and mantle-derived mafic magma modified/influenced by subduction components. The ca.100 Ma granodiorite could resultsin different forms of mineralization in various locations.Therefore,it is a critical factor for the mineralization and prospecting of Cu-polymetallic deposits in southwestern Fujian province. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics of Multiphase Mineralization of Jinzhuping Tungsten Deposit in Southern Jiangxi Province and Its Geological Significance YANG Junfeng, ZHANG Juan, LIU Xinxing, QIU Jiawei, WANG Meng, CHENG Jiawei, LU Kexuan, WANG Yingxue Geoscience    2023, 37 (06): 1449-1466.   DOI: 10.19657/j.geoscience.1000-8527.2023.068 Abstract （56）   HTML （17）    PDF（pc） （8885KB）（116）       Knowledge map    Save The Jinzhuping quartz vein-type tungsten deposit is located in the tungsten-polymetallic metallogenic belt in the eastern Nanling region, southern Jiangxi Province.The Yanshanian concealed granite is associated with the Tungsten mineralization, and the lithology is medium-coarse-grained (or porphyritic) biotite monzogranite.The early orebody was strongly affected by late hydrothermal metasomatism, showing multi-generational characteristics.At present, there is still a lack of precise chronology on the time of buried pluton and multi-stage mineralization.In this paper, zircon and wolframite LA-ICP-MS U-Pb dating methods are used to date the porphyrotic biotite monzolitic granite and three generations of wolframites in the deposit.Our data reveal the multistage metallogenic evolution, and we further discuss the mineralization process.The results show that porphyritic biotite monzogranite was formed at (155.2±0.7) Ma, whilst the three generationgs of wolframites were formed at (164.9±2.4) Ma, (157.4±1.0) Ma and (144.8±1.8) Ma.We considered that the concealed rock of Jinzhuping tungsten deposit was emplaced in 159-155 Ma, and the three stages of hydrothermal tungsten mineralization were formed in 164.9-144.8 Ma, which were the products of large-scale magmatism and mineralization in the Yanshanian Nanling tungsten-tin polymetallic metallogenic belt.The first two generations of tungsten mineralization age and granite emplacement age are within error, and is between the previously reported Middle to Late Jurassic for the Nanling metallogenic peak.Meanwhile, the tungsten mineralization age of the third generation is about 10 Ma later than the granite formation, which may represent the newfound Early Cretaceous tungsten mineralization after the Middle and Late Jurassic mineralization. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Characteristics of Structural Superimposed Halo and Deep Prospecting Prediction of Yongxin Gold Deposit, Duobaoshan Area,Heilongjiang Province LI Chenglu, FU Anzong, XU Wenxi, YUAN Maowen, LIU Baoshan, YANG Wenpeng, ZHAO Ruijun, ZHAO Zhonghai Geoscience    2023, 37 (03): 674-689.   DOI: 10.19657/j.geoscience.1000-8527.2023.012 Abstract （187）   HTML （7）    PDF（pc） （8511KB）（114）       Knowledge map    Save The Yongxin gold deposit is one of the major prospecting achievements in recent years in the periphery of the Duobaoshan ore concentration area in Heilongjiang Province. It is the first discovered large-scale epithermal-type gold deposit related to the Nenjiang-Heihe mélange belt. The orebody has dip angle of 20°-30°, strictly controlled by structures, and extends over 400-meter long and nearly 1,600-meter deep. Deep exploration shows that the orebody is obviously thinner and the grade is lower. To further clarify the mineralization potential at depth and guide future exploration, the tectonic superimposed halo samples were taken in different exploration lines of the mining area for geochemical analyses. The geochemical statistical analysis shows that the element assemblage at Yongxin comprises Au, Ag, Pb, Mo, W, Bi, Mn and Te, among which Au is the most direct and important indicator for the formation of gold orebodies and Ag-Te is an important associated element. Based on the axial distribution characteristics of the inner, middle, and outer zone anomalies of each indicator element in the orebody, the axial zoning sequence of orebody halo at Yongxin is established: Sb-As-Hg → Ag-Au-Te-Pb-Zn-Cu → (Bi)-Mo-Mn-Co. Among them, Sb-As-Hg are the frontal halo indicator elements, Ag-Au-Te-Pb-Zn-Cu are the near-ore indicator elements, Mo-Mn-Co are the terminal halo indicator elements. The orebody axial characteristics show that the frontal-terminal halo coexists in the margin of orebody, indicating possible existence of orebody in deep structures. According to the prediction mark of tectonic superimposed halo and geological mark, a concealed ore prediction target and a favorable ore-forming site are proposed on the horizontal projection map. The targets are located between No. 205 and 225 exploration lines, whilst the favorable ore-forming sites are located between No. 235 and 245 exploration lines. Both show the coexistence of frontal and terminal halo in the middle and lower parts of the orebody, and the anomalies of frontal and near-ore elements are obviously stronger than those of the terminal halo elements. This indicates that the orebody extends downward significantly, which shows that it is worthy of further deep exploration. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Research Progress and Prospect of Groundwater Pump and Treat Technology ZHANG Li, LIU Fei, YUAN Huiqing, LIANG Kaixuan Geoscience    2023, 37 (04): 977-985.   DOI: 10.19657/j.geoscience.1000-8527.2022.030 Abstract （113）   HTML （4）    PDF（pc） （5730KB）（114）       Knowledge map    Save Groundwater pump and treat technology (P&T) is a representative technology of groundwater reme-diation, and is at present widely used also to control and repair groundwater pollution. However, in the practical application of P&T technology, it is often interfered by the complexity of hydrogeological conditions and the special behavior of ground pollutant migration and transformation. The most important problem is tailing or rebound, which leads to low efficiency and high cost in the later stage of treatment. Based on expounding the development and evolution of P&T technology, we systematically analyzed its application conditions, technological pros and cons, system design optimization methods and its combined use with other technologies. We concluded that with the application of pumping treatment, it is more used for the pump of high concentration pollutants in the initial stage of pollution and hydraulic control to avoid pollutant diffusion. Currently, the goal of pumping changes from treatment to flow field control. The pumping/injecting wells are often located at the contamination source and plume and their upstream and downstream. The purposes of controlling pollutant diffusion and clean water diversion were achieved by pumping the contaminated water or injecting uncontaminated water into the ground to form a watershed. Our results provide suggestions for the flexible application of groundwater pump technology and the selection of prevention and control solutions for site groundwater pollution in China. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geoscience    2023, 37 (06): 0-0.   Abstract （50）      PDF（pc） （28724KB）（112）       Knowledge map    Save Related Articles | Metrics | Comments（0）

Select

Distribution Characteristics of Oolitic Beach in the 2nd and 3rd Members of Lower Triassic Feixianguan Formation, Southeastern Chongqing ZHAO Lingli, SONG Jinmin, YUAN Haifeng, XU Guaosheng, DENG Shuanglin, ZHAO Cong, JIN Xin, LI Liji, LI Pengwu, REN Jiaxin, LI Keran, FENG Yuxiang, FAN Jianping Geoscience    2023, 37 (05): 1208-1220.   DOI: 10.19657/j.geoscience.1000-8527.2022.100 Abstract （67）   HTML （4）    PDF（pc） （23362KB）（111）       Knowledge map    Save The Feixianguan Formation (FXGF) subdivision in southeastern Chongqing is established based on the lithologic-electrical identification mark by the outcrop measurement, thin-section microscopic observation, logging data and seismic data analysis.The distribution patterns of oolitic beach in the 2nd and 3rd members of FXGF are discussed.The results show that the stratigraphic framework of FXGF in southeastern Chongqing can be divided into four parts.The FXGF 1st Member is mainly composed of limestone with the characteristics of 80~105 API GR value and 75~200 Ω·m LLD value.The FXGF 2nd Member is mainly composed of micritic limestone and silty oolitic limestone.The GR value reduced to 11~31 API, and the resistivity value increased to 200~4205 Ω· m compared with the FXGF 2nd Member.While the FXGF 3rd Member is mainly composed of oolitic limestone and silty limestone.The logging value has little change compared with the FXGF 2nd Member.Only the top and bottom of the FXGF 3rd Member can be seen with high GR value.Argillaceous dolomite and argillaceous limestone are developed in the FXGF 4th Member with GR value increasing to 35~66 API and resistivity decreasing to 74~280 Ω·m (compared with the FXGF 3rd Member).In the study area, oolitic beach in the FXGF 2nd Member is developed in Quxian-Liangping and Fengdu-Zhongxian-Lichuan areas.Oolitic beaches of the FXGF 3rd Member were mainly developed around the Dianjiang-Liangping intertidal depression, which were distributed in a ring belt.The oolitic beach developed in the FXGF 3rd Member is thicker, more connectivity, more widely distributed, and larger in scale than that in the FXGF 2nd Member.The local sedimentary model during Feixianguan period is a rimmed carbonate platform.After clarifying the stratification scheme, we considered that the beach center in the platform migrated eastward with the regression during the 3rd Member of Feixianguan period. Table and Figures | Reference | Related Articles | Metrics | Comments（0）

Select

Geochemical Characteristics of Stream Sediments and Prospecting in the Middle Reach of the Nalinggele River, Qinghai Province ZHANG Wei, AN Maoguo, WANG Zhipeng, YANG Qi, CHEN Huaixin, MA Xiaofeng, ZHI Chenglong, XING Qitao, PEI Changshi, WANG Na, LIU Ming Geoscience    2023, 37 (03): 690-707.   DOI: 10.19657/j.geoscience.1000-8527.2022.042 Abstract （96）   HTML （11）    PDF（pc） （6460KB）（111）       Knowledge map    Save The middle reach of the Nalinggele River in Qinghai Province is located in the Qin-Qi-Kun ore domain and the Variscan Qimantag Dulan Fe-Co-Cu-Pb-Zn-Sn-W ore belt in the eastern Kunlun mineral province. Over ten metal deposits/prospects have been discovered in/around this area, with good prospects for gold, iron, lead, zinc, copper, and nickel exploration. This study is based on the new 20-element analysis on stream sediment samples, and statistical analysis of element distribution and characteristic parameters to summarize the enrichment and dispersion regularities, element assemblage characteristics, and their relationship with metallogenic conditions. The results show that Pb, Bi, and Zn are significantly enriched in the Baishahe Formation, with a high mineralization index. Cu, Cr, Ni, Co, and V are significantly enriched in the Tanjianshan Group. The high-temperature Indosinian felsic magmatic activity could provide sufficient heat for the metal remobilization (e.g., Cu, Pb, Zn)in the formation. The skarn belt formed by contact metamorphism and metasomatism between the strata and the Indosinian felsic magma represents a favorable site for skarn-type Cu, Pb, Zn polymetallic mineral exploration. In combination with the geological conditions and geochemical characteristics of mineralization, a total of 39 geochemical comprehensive anomalies have been delineated, and 5 prospects have been defined. Among them, the Yemaquan-Niukutou-Heishan Cu-Au-Sb and the Ketihar-Hongweishan Cu-Co-Ni-V polymetallic prospects can be regarded as the key Cu polymetallic metallogenic prospect zone in the region with relatively high metallogenic potential. This study provides a reference for the optimization of multiple non-ferrous metal mineral target areas in the region, resource potential evaluation, and further geological exploration work. Table and Figures | Reference | Related Articles | Metrics | Comments（0）