China Geology最新文献

{"title":"Timing, geometry, and kinematics of the Yilan-Yitong fault zone in the Northern Tan-Lu fault system of Northeast Asia","authors":"Liang Qiu ,&nbsp;Yu Fu ,&nbsp;Dan-Ping Yan ,&nbsp;Tian-heng Wang ,&nbsp;Wei Gan ,&nbsp;Cheng-ming Li ,&nbsp;Ruo-yan Kong ,&nbsp;Rong Chu ,&nbsp;Xiao-yu Chen ,&nbsp;Rui Zhang ,&nbsp;Shou-heng Sun ,&nbsp;Xiao-yu Dong","doi":"10.31035/cg20230060","DOIUrl":"10.31035/cg20230060","url":null,"abstract":"<div><div>The largest Tan-Lu active fault system in northeastern Asia, spans approximately 3500 km in length and varies in width from 10 km to 200 km. In 1668, an earthquake with a magnitude of 8.5 occurred in Tancheng, causing the loss of over 50000 lives. To constrain the timing and process of the Tan-Lu fault system on eastern Asian margin, this study presents the field mapping, thin section observation, geochronology, and microanalysis of Weiyuanpu-Yehe ductile shear zone (WYSZ) of the northern Tan-Lu fault system. Kinematic indicators and microstructures suggest a sense of sinistral strike-slip. The deformation temperature of the mylonite is mediate to high based on the quartz deformation, c-axis fabrics. The differential stress of the shear zone is 20‒40 MPa using quartz paleopiezometry. The dikes within the shear zone yielded zircon U-Pb ages of 165‒163 Ma. However, due to the ambiguous geological relationship between the dikes and shear zone, additional geochronology is warranted. Since the Mesozoic era, based on the exposure of mylonite and dikes, the upper crust has been extensively eroded, exposing the ductile shear zone. Moreover, the understanding of the geometry and process of pre-existing structures has fundamental implications for predicating the potential earthquakes for the Tan-Lu fault system.</div></div>","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 265-280"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution and role of fluorine in the aquatic ecosystem (mineral springs, groundwater, tributaries, Baikal water, and the Angara water source) of Lake Baikal, Russia","authors":"Valentina Grebenshchikova ,&nbsp;Mikhail Kuzmin ,&nbsp;Anna Novopashina ,&nbsp;Elena Kuz'mina","doi":"10.31035/cg20230100","DOIUrl":"10.31035/cg20230100","url":null,"abstract":"<div><div>Several conjugate components represent the aquatic ecosystem of Lake Baikal: Baikal water (surface and deep water), groundwater from boreholes, water of numerous Baikal tributaries, cold and hot mineral springs around Lake Baikal, and the Angara River, the only runoff reflecting all this aquatic diversity. River waters in the Baikal region are known to be deficient in some vital elements, including fluorine. This article discusses the features of the fluorine distribution in the water from the conjugate components of the Baikal ecosystem. Fluorine ion concentrations in the water of the Baikal ecosystem was determined using the potentiometric method. The study represents the monitoring that was carried out between 1997 and 2022 years. We determine likely causes of high and low fluorine concentrations in the water from different components, propose and substantiate the fluorine sources, geological and geochemical model of its influx and distribution features in the water of the Baikal ecosystem.</div></div>","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 303-313"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geology, mineralization and model of the giant Maoping carbonate-hosted Pb-Zn deposit (5 Mt), South China","authors":"Ye He ,&nbsp;Bang-Tao Sun ,&nbsp;Hai-Peng Wang ,&nbsp;Jia-Xi Zhou ,&nbsp;Yan-Jun Li ,&nbsp;Foteini Drakou ,&nbsp;Kai Luo ,&nbsp;Saleh Ibrahim Bute","doi":"10.31035/cg2024142","DOIUrl":"10.31035/cg2024142","url":null,"abstract":"<div><div>The giant Upper Yangtze Pb-Zn metallogenic province, also known as the Sichuan-Yunnan-Guizhou (SYG) Pb-Zn province hosting &gt;500 carbonate-hosted epigenetic Pb-Zn deposits that contain &gt;20 Mt Pb + Zn base metal reserves. The giant Maoping Pb-Zn deposit is the second largest deposit in this province and owns &gt;5 Mt Pb + Zn metal reserves with ore grades of 12 wt.%-30 wt.% Pb + Zn. Such large tonnages and high grades make it among the top 100 similar mineral deposits in the world. The ore bodies are predominantly located within the strata of the Upper Devonian (Zaige Formation) and Lower (Baizuo Formation)-Upper (Weining Formation) Carboniferous. The principal ore minerals consist of galena (Gn), sphalerite (Sp), and pyrite (Py), while the primary gangue minerals include dolomite (Dol), calcite (Cal), and quartz (Qtz). Three mineralization stages of carbonate minerals have been identified: (1) pre-sulfide stage 1, (2) syn-sulfide stage 2, and (3) post-sulfide stage 3. Trace elements and C-O-Sr isotopes of three stages’ carbonate minerals, together with S-Pb isotopes of sulfides, revealing that the metamorphic basement rocks played the role of the metal source during the early stage of Pb-Zn mineralization, whereas the metal contribution of the sedimentary wall rocks found to be more prominent during the late stage of Pb-Zn mineralization. In addition, the dissolution of marine carbonate rocks and CO₂ degassing may have also played an important role in the formation of the Maoping deposit. Furthermore, syn-sulfide stage 2 calcite has a U-Pb age of 214 ± 20 Ma obtained by LA-ICPMS in-situ analyses, suggesting that the hydrothermal mineralization occurred during the Triassic. Our study proposes a new coupled metallogenic model of fluid-structure-lithology assemblage and provides new insights about the formation and evolution of the Maoping deposit with significant implication for understanding and exploration of similar Pb-Zn deposits worldwide.</div></div>","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 431-453"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LA-ICP-MS zircon U-Pb dating of dacite in the Sangthong Au mining area, Luang Prabang-Loei metallogenetic belt, SW Laos","authors":"Lin-nan Guo ,&nbsp;Zhen-wen Liao ,&nbsp;Chun-mei Huang ,&nbsp;Yong-fei Yang ,&nbsp;Bin Zhang ,&nbsp;Si-wei Xu ,&nbsp;Hui-min Liang ,&nbsp;Xiang-ting Zeng","doi":"10.31035/cg20240051","DOIUrl":"10.31035/cg20240051","url":null,"abstract":"","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 454-456"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First discovery of Cretaceous tuffs in the Zhenyuan area, southwestern Ordos Basin, China: Constraints from zircon U-Pb dating","authors":"Yin Chen ,&nbsp;Lu-lu Chen ,&nbsp;Jian-guo Li ,&nbsp;Hua-lei Zhao","doi":"10.31035/cg2023109","DOIUrl":"10.31035/cg2023109","url":null,"abstract":"","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 457-459"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithofacies palaeogeography, depositional model and shale gas potential evaluation in the O3-S1 Wufeng-Longmaxi Formation in the Sichuan Basin, China","authors":"Xiang-ying Ge ,&nbsp;Chuan-long Mou ,&nbsp;Xin Men ,&nbsp;Qian Hou ,&nbsp;Bin-song Zheng ,&nbsp;Wei Liang","doi":"10.31035/cg20230015","DOIUrl":"10.31035/cg20230015","url":null,"abstract":"<div><div>The black shales of Wufeng and Longmaxi Formation (Late Ordovician-Early Silurian period) in Sichuan Basin are the main strata for marine shale gas exploration, which have a yearly shale gas production of 228×10⁸ m³ and cumulative shale gas production of 919×10⁸ m³. According to the lithological and biological features, filling sequences, sedimentary structures and lab analysis, the authors divided the Wufeng /Guanyinqiao and Longmaxi Formations into shore, tidal flat, shoal, shallow water shelf and deep water shelf facies, and confirmed that a shallow water deposition between the two sets of shales. Although both Formations contain similar shales, their formation mechanisms differ. During the deposition of Wufeng shale, influenced by the Caledonian Movement, the Central Sichuan and Guizhou Uplifts led to the transformation of the Sichuan Basin into a back-bulge basin. Coinstantaneous volcanic activity provided significant nutrients, contributing to the deposition of Wufeng Formation black shales. In contrast, during the deposition of Longmaxi shale, collisions caused basement subsidence, melting glaciers raised sea levels, and renewed volcanic activity provided additional nutrients, leading to Longmaxi Formation black shale accumulation. Considering the basic sedimentary geology and shale gas characteristics, areas such as Suijiang-Leibo-Daguan, Luzhou-Zigong, Weirong-Yongchuan, and Nanchuan-Dingshan are identified as key prospects for future shale gas exploration in the Wufeng-Longmaxi Formations.</div></div>","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 338-359"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochronology, petrogenesis, and tectonic characteristics of a volcanic–intrusive complex on the northern margin of North China Craton and its limitation on the closing time of the Paleo-Asian Ocean (245 Ma)","authors":"Sen Wang ,&nbsp;Hong-jie Qu ,&nbsp;Shuan-hong Zhang ,&nbsp;Huan Wang ,&nbsp;Meng-ying Cai ,&nbsp;Ge-xue Zhao","doi":"10.31035/cg2023090","DOIUrl":"10.31035/cg2023090","url":null,"abstract":"<div><div>The Central Asian Orogenic Belt (CAOB) is one of the largest and best preserved accretionary type orogenic belts in the world. Due to its complex tectonic history, the timing and location of the final closure of the Paleo-Asian Ocean and its tectonic evolution have been hotly discussed. To determine the petrogenesis and tectonic characteristics of the poorly exposed Triassic volcanic-intrusive complex on the northern margin of the eastern North China Craton, the authors conducted a study of zircon Lu-Hf isotopes, integrated with zircon U-Pb dating and whole-rock geochemistry. Zircons from eight representative volcanic and intrusive samples yielded concordant U-Pb ages of 251–245 Ma. The volcanic and intrusive rocks are all characterized by enrichments in large ion lithophile elements and depletions in high field strength elements, and they have features similar to those of highly fractionated I-type granites. The <em>ε</em>_Hf(<em>t</em>) values for the volcanic and intrusive rocks, respectively, range from –1.69 to +3.75 (mean=+1.22) and –2.17 to +3.15 (mean=+0.38), with two-stage model ages of 1035–1345 Ma (mean=1196 Ma) and 1073–1401 Ma (mean=1250 Ma). The Hf isotopic features indicate that these rocks were formed by partial melting of young crustal material that was newly accreted from the depleted mantle, together with a degree of contamination by other crustal material. The volcanic–intrusive complex was related to an active continental margin in a volcanic arc and syn-collisional setting, indicating that the Paleo-Asian Ocean was closed after the Middle Triassic (245 Ma) along the northern margin of the North China Craton. This provides a constraint on the timing of the change in tectonic setting in this area from compression to extension. The results enhance our understanding of the evolution of the Paleo-Asian Ocean.</div></div>","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 373-388"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landslide susceptibility assessment based on an interpretable coupled FR-RF model: A case study of Longyan City, Fujian Province, Southeast China","authors":"Zong-yue Lu ,&nbsp;Gen-yuan Liu ,&nbsp;Xi-dong Zhao ,&nbsp;Kang Sun ,&nbsp;Yan-si Chen ,&nbsp;Zhi-hong Song ,&nbsp;Kai Xue ,&nbsp;Ming-shan Yang","doi":"10.31035/cg2024123","DOIUrl":"10.31035/cg2024123","url":null,"abstract":"<div><div>To enhance the prediction accuracy of landslides in in Longyan City, China, this study developed a methodology for geologic hazard susceptibility assessment based on a coupled model composed of a Geographic Information System (GIS) with integrated spatial data, a frequency ratio (FR) model, and a random forest (RF) model (also referred to as the coupled FR-RF model). The coupled FR-RF model was constructed based on the analysis of nine influential factors, including distance from roads, normalized difference vegetation index (NDVI), and slope. The performance of the coupled FR-RF model was assessed using metrics such as Receiver Operating Characteristic (ROC) and Precision-Recall (PR) curves, yielding Area Under the Curve (AUC) values of 0.93 and 0.95, which indicate high predictive accuracy and reliability for geological hazard forecasting. Based on the model predictions, five susceptibility levels were determined in the study area, providing crucial spatial information for geologic hazard prevention and control. The contributions of various influential factors to landslide susceptibility were determined using SHapley Additive exPlanations (SHAP) analysis and the Gini index, enhancing the model interpretability and transparency. Additionally, this study discussed the limitations of the coupled FR-RF model and the prospects for its improvement using new technologies. This study provides an innovative method and theoretical support for geologic hazard prediction and management, holding promising prospects for application.</div></div>","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 281-294"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heavy metal pollution in water and soil and associated health risks in a tin mining region of Hunan Province, Central China","authors":"Lan Wang,&nbsp;Jian-feng Li,&nbsp;Xiu-wen Liu,&nbsp;Li-xiao Feng","doi":"10.31035/cg2023141","DOIUrl":"10.31035/cg2023141","url":null,"abstract":"<div><div>To assess the effect of mining activity on heavy metal pollution and associated health risks in tin mining regions, water and soil sampling was conducted near a tin mining site in Hunan Province. The content and distribution of heavy metals were determined. Pollution, ecological risks, and potential health hazards were evaluated using the ground accumulation index, potential ecological risk index, and health risk assessment models, respectively. The results indicated elevated levels of heavy metals in water and soil samples compared to acceptable background values. Ground accumulation index assessment revealed extreme pollution of soil with As and Cd and moderate pollution with Cu, Pb, and Zn. Cr and Hg were categorized as non-pollutants. Water samples exhibited extreme pollution levels of Hg, Cr, Cd, and As; moderate pollution levels of Pb; and moderate to high pollution levels of Cu and Zn. The tin mining area demonstrated a significantly high level of potential ecological risk, where As and Cd were the primary risk elements in soil, whereas Cr, Cd, and As contributed predominantly to water ecological risk. The human health risk assessment highlighted As, Cd, Cr, Hg, Pb, and Cu in water and As and Pb in soil as the principal non-carcinogenic factors. The primary carcinogenic factors were As, Cr, and Cd in water and As in soil, with As posing the greatest risk for non-carcinogenic and carcinogenic effects. Furthermore, oral intake was the primary exposure route, with children being particularly vulnerable to the adverse effects of heavy metal pollution.</div></div>","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 314-324"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tight sandstone diageneses, evolution, and controls on high-graded reservoirs in slope zones of foreland basins: A case study of the fourth Member of Xujiahe Formation, Tianfu gas field, Sichuan Basin","authors":"Zhi-min Jin ,&nbsp;Ji-rong Xie ,&nbsp;Zheng-lin Cao ,&nbsp;Yu-chao Qiu ,&nbsp;Chao Zheng ,&nbsp;Liang-biao Lin ,&nbsp;Yu Yu","doi":"10.31035/cg20230072","DOIUrl":"10.31035/cg20230072","url":null,"abstract":"<div><div>The Triassic Xujiahe Formation in the slope zone of the Sichuan foreland basin is a new field of continental tight gas exploration in recent years. The fourth member of the Xujiahe Formation (Xu4 Member), the major interval in the Jianyang Block of the Tianfu gas field in the basin, is characterized by considerable buried depth, tight reservoirs, and strong heterogeneity. By using cast thin section, X-ray diffraction (XRD), scanning electron microscopy (SEM), fluid inclusion thermometry, and core analysis, the reservoir rock types, dominant diageneses, diagenetic history, and controls on high-graded reservoirs were investigated. It is found that the Xu4 Member in Jianyang mainly consists of lithic feldspar sandstones and feldspar lithic sandstones, followed by lithic quartz sandstones. High-energy hydrodynamic conditions in the microfacies of underwater distributary channels and mouth bars are beneficial to the preservation of primary pores and the occurrence of secondary pores, and there are no significant differences in petrophysical properties between these two microfacies. Compaction and calcareous cementation are the dominant controls on reservoir porosity decrease in the Xujiahe Formation; corrosion is the major contributor to porosity increase by generating secondary dissolved pores, e.g. intragranular dissolved pores and intergranular dissolved pores, as major reservoir space in the study area. Fracture zones around the faults inside the Xujiahe Formation (fourth−order faults) are favorable for proximal tight gas accumulation, preservation, and production. The research findings have been successfully applied to explore the Xujiahe Formation in the slope zone of the Sichuan foreland basin. They can be referential for other similar tight sandstone gas accumulations.</div></div>","PeriodicalId":45329,"journal":{"name":"China Geology","volume":"8 2","pages":"Pages 325-337"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}