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China Geology 2024年第2期7卷 237-247页

作者： Yu-feng Wang Qian-gong Cheng Qi Zhu Department of geological Engineering Southwest Jiaotong UniversityChengdu 610031China Sichuan Highway Planning SurveyDesign and Research Institute LtdChengdu 610041China

Airblasts,as one common phenomenon accompanied by rapid movements of landslides or rock/snow avalanches,commonly result in catastrophic damages and are attracting more and more scientific *** quantitatively analyze the intensity of airblast initiated by landslides,the Wangjiayan landslide,occurred in the Wenchuan earthquake,is selected here with the landslide propagation and airblast evolution being studied using FLUENT by introducing the Voellmy rheological *** results reveal that:(1)For the Wangjiayan landslide,its whole travelling duration is only 12 s with its maximum velocity reaching 36 m/s at t=10 s;(2)corresponding to the landslide propagation,the maximum velocity,28 m/s,of the airblast initiated by the landslide also appears at t=10 s with its maximum pressure reaching594.8 Pa,which is equivalent to violent storm;(3)under the attack of airblast,the load suffered by buildings in the airblast zone increases to 1300 Pa at t=9.4 s and sharply decreased to-7000 Pa as the rapid decrease of the velocity of the sliding mass at t=10 s,which is seriously unfavorable for buildings and might be the key reason for the destructive collapse of buildings in the airblast zone of the Wangjiayan landslide.

关键词： Landslide Voellmy rheological law 3D FLUENT simulation Airblast Intensity Building destructive collapse Wenchuan earthquake geological hazards survey engineering

Thermal and exhumation history of the Songnan Low Uplift,Qiongdongnan Basin:constraints from the apatite fission-track and zircon(U-Th)/He thermochronology

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Acta Oceanologica Sinica 2024年第4期43卷 40-49页

作者： Xiaoyin Tang Kaixun Zhang Shuchun Yang Shuai Guo Xinyan Zhao Zhizhao Bai Institute of Geomechanics Chinese Academy of Geological SciencesBeijing 100081China Key Laboratory of Paleomagnetism and Tectonic Reconstruction Ministry of Natural ResourcesBeijing 100081China Key Laboratory of Petroleum Geomechanics China Geological SurveyBeijing 100081China China National Offshore Oil Corporation(CNOOC)Research Center Beijing 100028China

Significant advancements have been made in the study of Mesozoic granite buried hills in the Songnan Low Uplift(SNLU)of the Qiongdongnan *** findings indicate that the bedrock buried hills in this basin hold great potential for *** samples taken from the granite buried hills in the SNLU were analyzed using apatite fission track(AFT)and zircon(U-Th)/He data to unravel the thermal history of the basement *** information is crucial for understanding the processes of exhumation and alteration that occurred after its *** modeling of a sample from the western bulge of the SNLU revealed a prolonged cooling event from the late Mesozoic to the Oligocene period(~80-23.8 Ma),followed by a heating stage from the Miocene epoch until the present(~23.8 Ma to present).In contrast,the sample from the eastern bulge experienced a more complex thermal *** underwent two cooling stages during the late Mesozoic to late Eocene period(~80-36.4 Ma)and the late Oligocene period(~30-23.8 Ma),interspersed with two heating phases during the late Eocene to early Oligocene period(~36.4-30 Ma)and the Miocene epoch to recent times(~23.8-0 Ma),*** differences in exhumation histories between the western and eastern bulges during the late Eocene to Oligocene period in the SNLU can likely be attributed to differences in fault *** typical passive continental margin basins,the SNLU has experienced accelerated subsidence after the rifting phase,which began around 5.2 Ma *** possible mechanism for this abnormal post-rifting subsidence may be the decay or movement of the deep thermal source and the rapid cooling of the ***-term and multi-episodic cooling and exhumation processes play a key role in the alteration of bedrock and contribute to the formation of *** the other hand,rapid post-rifting subsidence(sedimentation)promotes the formation of cap rocks.

关键词： granite buried hills (U-Th)/He dating fission-track dating exhumation Songnan Low Uplift

Stratigraphic framework and sedimentary evolution during the Cryogenian-Ediacaran transition in northeastern Sichuan Basin,South China

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Petroleum Science 2024年第2期21卷 823-835页

作者： Yi Zhang Hong-Wei Kuang Yong-Qing Liu Qiang Shi Dong-Ge Wang Ke-Ning Qi Yu-Chong Wang Da-Wei Qiao Xiao-Shuai Chen Li-Zhi Wu Meng Tian Long Chen Yi Wei Liao-Yuan Song Jian Li Zi-Gang Wu Yun-Qian Liu Xuan-Chun Liu An-Qing Chen Zhi-Wei Liao Institute of Geology Chinese Academy of Geological SciencesBeijing100037China State Key Laboratory of Coal Mine Disaster Dynamics and Control School of Resources and Safety EngineeringChongqing UniversityChongqing400044China No.205 geological Team Chongqing Bureau of Geology and Minerals ExplorationChongqing401121China Chongqing Institute of geological survey Chongqing401122China Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources Chengdu University of TechnologyChengdu610059SichuanChina

The northeastern Sichuan area in the northern Yangtze margin has unique Ediacaran geological records,especially the Doushantuo Formation(DST),and become a hot research area in recent ***,the Cryogenian-Ediacaran(C-E)boundary has not been precisely identified,which restricts the in-depth study of geological information during this crucial transitional period and is unfavorable for a systematic and complete understanding of the Yangtze Block and even the global paleogeographic *** study conducted stratigraphy,sedimentology,and chronostratigraphy to establish the stratigraphic framework and sedimentary evolution of the C-E transition strata in northeastern *** results showed that the Ediacaran sediments,without the cap dolomite,unconformably overlaid the Cryogenian sediments in the studied *** Member II of the DST,characterized by 50-160 m of red-green sandstone(approximately equivalent to the original Chengkou“Guanyinya Formation”),directly overlaid the Cryogenian sediments and displayed a 623±2.3 Ma maximum depositional age from the detrital zircon U-Pb *** stratigraphic correlations indicate that the C-E transition strata in northeastern Sichuan had a consistent lithological association and sedimentary sequence characteristics but differed from the Three ***,the upper Nantuo massive glacial diamictites transition to the icebergs rafted lonestone-bearing mudstones at the top,then change upward to DST barrier coast *** proposed DST of the northeastern Sichuan Basin was divided into three lithostratigraphic members without the regional Member I cap dolomite:(i)Member II purple-red,gray-green sandstone strata,(ii)MemberⅢblack mudstone strata,and(iii)Member IV P-Mn bearing *** the C-E transition,the study area experienced(i)the global deglaciation stage in the terminal Marinoan glaciation and(ii)the filling-leveling up stage with clastic rocks in the early ***,the early Ediacaran

关键词： Marinoan glaciation Doushantuo formation Cap dolomite Deglacial and coastal deposits Detrital zircon U-Pb dating

Multiple isotopes reveal the driving mechanism of high NO_(3)^(-) level and key processes of nitrogen cycling in the lower reaches of Yellow River

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Journal of Environmental Sciences 2024年第4期138卷 597-606页

作者： Qianqian Zhang Huiwei Wang Lu Liu Tianlun Zhai Xueqing Zhang Hebei and China geological survey Key Laboratory of Groundwater Remediation Institute of Hydrogeology and Environmental GeologyChinese Academy of Geological SciencesHebei 050061China Geo-Environmental Monitoring Institute of Hebei Province Hebei 050011China Hebei Provincial Laboratory of Water Environmental Science Hebei 050037China Hebei Provincial Academy of Ecological Environmental Science Hebei 050037China

The continuous increase of nitrate(NO_(3)^(-))level in rivers is a hot issue in the ***,the driving mechanism of high NO_(3)^(-)level in large rivers is still lacking,which has limited the use of river water and increased the cost of water *** this study,multiple isotopes and source resolution models are applied to identify the driving mechanism of high NO_(3)^(-)level and key processes of nitrogen cycling in the lower reaches of the Yellow River(LRYR).The major sources of NO_(3)^(-)were sewage and manure(SAM)in the low-flow season and soil nitrogen(SN)and chemical fertilizer(CF)in the high-flow *** was the most key process of nitrogen cycling in the ***,in the biological removal processes,denitrification may not occur *** temporal variation of contributions of NO_(3)^(-)sources were estimated by a source resolution model in the *** proportional contributions of SAM and CF to NO_(3)^(-)in the low-flow and high-flow season were 32.5%-52.3%,44.2%-46.2%and 36.0%-40.8%,54.9%-56.9%,*** driving mechanisms of high NO_(3)^(-)level were unreasonable sewage discharge,intensity rainfall runoff,nitrification and lack of nitrate removal *** control the NO_(3)^(-)concentration,targeted measures should be implemented to improve the capacity of sewage and wastewater treatment,increase the utilization efficiency of nitrogen fertilizer and construct ecological *** study deepens the understanding of the driving mechanism of high nitrate level and provides a vital reference for nitrogen pollution control in rivers to other area of the world.

关键词： Nitrate Driving mechanism Nitrogen cycle Source apportionment Transformation Yellow River

Groundwater Quality and Vulnerability Assessment in a Semiarid Karst Region of Northern China

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Journal of Earth Science 2024年第1期35卷 313-316页

作者： Ran An Shu Wang Zongjun Gao Zhenyan Wang Wei Li Qijun Deng Lü Lin Yuanqing Liu Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Shandong University of Science and Technology Qingdao 266510China Center for Hydrogeology and Environmental Geology survey China Geological SurveyBaoding 071051China

Groundwater plays a critical role in maintaining ecological balance and ensuring social operations,especially in arid and semiarid regions(Hu et al.,2023;Han et al.,2022;Ma et al.,2014).The over-exploitation of groundwater,coupled with the influx of pollutants from human activities into the soil,significantly degrades the environment in certain regions(Jia et al.,2019;Famiglietti,2014;Giordano,2009;Konikow and Kendy,2005;Bohlke,2002;Shah et al.,2000).

关键词： groundwater Groundwater Vul

Influence of tectonic preservation conditions on the nanopore structure of shale reservoir: A case study of Wufeng-Longmaxi Formation shale in western Hubei area, south China

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Petroleum Science 2024年第4期21卷 2203-2217页

作者： Meng Xiang Shang Xu Ya-Ru Wen Qi-Yang Gou Bing-Chang Liu National Key Laboratory of Deep Oil and Gas China University of Petroleum (East China) Hubei Key Laboratory of Resources and Eco-environment Geology Hubei Geological Survey Key Laboratory of Tectonics and Petroleum Resources Ministry of Education China University of Geosciences

Tectonism is one of the dominant factors affecting the shale pore structure. However, the control of shale pore structure by tectonic movements is still controversial, which limits the research progress of shale gas accumulation mechanism in the complex tectonic region of southern China. In this study, 34 samples were collected from two exploratory wells located in different tectonic locations. Diverse experiments,e.g., organic geochemistry, XRD analysis, FE-SEM, low-pressure gas adsorption, and high-pressure mercury intrusion, were conducted to fully characterize the shale reservoir. The TOC, Ro, and mineral composition of the shale samples between the two wells are similar, which reflects that the shale samples of the two wells have proximate pores-generating capacity and pores-supporting ***, the pore characteristics of shale samples from two wells are significantly different. Compared with the stabilized zone shale, the porosity, pore volume, and specific surface area of the deformed zone shale were reduced by 60.61%, 64.85%, and 27.81%, respectively. Moreover, the macroscopic and fine pores were reduced by 54.01% and 84.95%, respectively. Fault activity and uplift denudation are not conducive to pore preservation, and the rigid basement of Huangling uplift can promote pore preservation. These three factors are important reasons for controlling the difference in pore structure between two wells shales. We established a conceptual model of shale pores evolution under different tectonic preservation conditions. This study is significant to clarify the scale of shale gas formation and enrichment in complex tectonic regions, and helps in the selection of shale sweet spots.

关键词： Shale gas Pore structure Tectonic preservation conditions Shale gas enrichment mechanism

Petrogenesis and tectonic implications of the Silurian adakitic granitoids in the eastern segment of the Qilian Orogenic Belt,Northwest China

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Acta Geochimica 2024年第1期43卷 72-86页

作者： Jiao-Long Zhao Xiao-Jun Huang Pei-Qing Hu Zhen-Xi Yang Ying Fan Er-Teng Wang Fu-Bo Yang Jing-Yu Zhang School of Earth Sciences Key Laboratory of Mineral Resources in Western China(Gansu Province)Lanzhou UniversityLanzhou 730000China Nuclear Industry 247 Brigade Tianjin North China Geological Survey BureauTianjin 301800China Fourth Institute of geological and Mineral Exploration of Gansu Provincial Bureau of Geology and Mineral Resources Jiuquan 735000China

Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon U–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline *** are peraluminous in composition and have relatively depleted Nd isotopic [ε_(Nd)(t) =(-3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Postcollisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.

关键词： Silurian adakitic granitoids Petrogenesis Tectonic setting Qilian Orogenic Belt

Enhancing geological Understanding and Identifying Gold Anomalies in the Ailaoshan Orogen

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 441-453页

作者： ZHAO Shiyu YANG Lin SONG Yiwei DONG Yuntao FENG Lihao LI Huajian WU Junyu WANG Qingfei State Key Laboratory of geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China Xi’an Center of Mineral Resources survey China Geological SurveyXi’an 710010China Yunnan Gold Mining Industry Group Kunming 650299China Jiangxi Provincial Key Laboratory of Genesis and Prospect for Strategic Minerals East China University of TechnologyNanchang 330013China Frontiers Science Center for Deep-time Digital Earth China University of Geosciences(Beijing)Beijing 100083China

The Ailaoshan Orogen in the southeastern Tibet Plateau,situated between the Yangtze and Simao blocks,underwent a complex structural,magmatic,and metamorphic evolution resulting in different tectonic subzones with varying structural lineaments and elemental *** elements can conceal or reduce anomalies due to the mutual effect between different anomaly *** the whole zone into subzones based on tectonic settings,ore cluster areas,or sample catchment basins(Scb),geochemical and structural anomalies associated with gold(Au)mineralization have been identified utilizing mean plus twice standard deviations(Mean+2STD),factor analysis(FA),concentration-area(CA)modeling of stream sediment geochemical data,and lineament density in both the Ailaoshan Orogen and the individual *** FA in the divided 98 Scbs with 6 Scbs containing Au deposits can roughly ascertain unknown rock types,identify specific element associations of known rocks and discern the porphyry or skarn-type Au *** with methods of Mean+2STD and C-A model of data in the whole orogen,which mistake the anomalies as background or act the background as anomalies,the combined methods of FA and C-A in the separate subzones or Scbs works well in regional metallogenic potential *** of lineament densities with a 10-km circle diameter is not suitable to locate Au deposits because of the delineated large areas of medium-high lineament *** contrast,the use of circle diameters of 1.3 km or 1.7 km in the ore cluster scale delineates areas with a higher concentration of lineament density,consistent with the locations of known Au *** analyzing the map of faults and Au anomalies,two potential prospecting targets,Scbs 1 and 63 with a sandstone as a potential host rock for Au,have been identified in the Ailaoshan *** use of combined methods in the divided subzones proved to be more effective in improving geological understanding and identifying

关键词： minerology geochemistry gold stream sediment sample catchment basin concentration-area model lineament density Ailaoshan Orogen

Geochronology,Geochemistry,and Sr-Nd-Hf Isotopes of the Diorite Porphyrites from the Weining Beishan Area,Ningxia Hui Autonomous Region:Constraints on Their Source and Tectonic Implications

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Journal of Earth Science 2024年第2期35卷 462-475页

作者： Anlu Liu Lianfu Hai Jinke Liu Xiaojun Zhang Haifeng Li Fengshun Zhao Guoliang Zhao Jinhe Bai Yifu Museum China University of GeosciencesWuhan430074China School of Earth Resources China University of GeosciencesWuhan430074China Mineral geological survey Institute of Ningxia Hui Autonomous Region Yinchuan750021China National Demonstration Center for Experimental Mineral Exploration Education China University of GeosciencesWuhan430074China Coal geological survey Institute of Ningxia Hui Autonomous Region Yinchuan750021China Zhuhai Engineering Investigation Institute of Guangdong Province Zhuhai519000China

The Weining Beishan area of Ningxia Hui Autonomous Region is located at on the western edge of the Helanshan tectonic belt,which is a tectonic joint among Alxa Block,Ordos Block,and North Qilian orogenic ***,the tectonic evolution of this area remains unclear due to the lack of magmatic *** paper conducted researches on geochronology,geochemistry,and Sr-Nd-Hf isotopes of the diorite porphyrites exposed in the Weining Beishan *** zircon U-Pb dating yields two ages of 145.0±1.1 and 146.2±1.5 Ma,and the whole-rock geochemical data indicate that the diorite porphyrites are metaluminous to weakly peraluminous and high-K calc-alkaline *** characteristics of highly initial^(87)Sr/^(86)Sr ratios(0.70816 to 0.71047),negativeε_(Nd)(t)(−8.9 to−8.4),and negativeε_(Hf)(t)(−13.8 to−21.2)indicate that the diorite porphyrites originated from partial melting of the middle-lower ancient crust related to the North China *** with the regional geology,we suggested that partial melting was triggered by a tectonic activity of deep faults cutting through the crust under the regional stress transformation from compressing to extension during the Late Jurassic–Early Cretaceous,which is probably related to the westward subduction of the Paleo-Pacific Plate.

关键词： zircon U-Pb dating Sr-Nd-Hf isotopes magma source diorite porphyrite Weining Beishan area Ningxia Hui Autonomous Region geochronology geochemistry

Organic Matter Accumulation in the Upper Permian Dalong Formation from the Lower Yangtze Region,South China

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 150-167页

作者： FANG Chaogang ZHANG Chengcheng MENG Guixi XU Jinlong XU Naicen LI Hualing LIU Mu LIU Bo Institute of International Rivers and Eco-Security Yunnan UniversityKunming 650500China Nanjing Center China Geological SurveyNanjing 210016China Exploration Research Institute Anhui Provincial Bureau of Coal GeologyHefei 230088China China United Coalbed Methane Corporation Ltd. Beijing 100015China geological survey of Anhui Province Hefei 230001China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source ***,the mechanism of organic matter(OM)enrichment throughout this period is still *** on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM *** Phases are distinguished based on the TOC and environmental *** Phase I,anoxic conditions driven by water restriction enhanced OM *** Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM *** Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation *** IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic *** Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary *** I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.

关键词： geochemistry redox condition primary productivity OM accumulation Lopingian/Changhsingian Lower Yangtze region