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Depositional model of Permian Luodianian volcanic island and its impact on the distribution of fusulinid assemblage in southern Qinghai,Northwest China

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Science China Earth Sciences 2008年第4期51卷 594-607页

作者： niu zhijun XU AnWu WANG JianXiong DUAN QiFa ZHAO XiaoMing YAO HuaZhou Yichang Institute of Geology and Mineral Resources China Geological SurveyYichang 443003China

Pan-riftizational tectonic activity reached climax at Luodianian (Permian) in the East Tethyan Domain, Qinghai-Tibet Plateau. Because of eruptive volcanics and influence of terrigenous materials, a complex volcanic-sedimentary landform formed on the sea floor in southern Qinghai. Four sedimentary facies types were recognized based on detailed field mapping. Spatially, platform facies volcanic-limestone type was located at the center belt approximately trending NWW, surrounded by shallow water slope facies tuff/tuffite type at the two flanks and deep water slope facies breccia/calcirudite at the most outside. The depression facies sandstone-mudstone type, which comprised mainly mudstone, de-posited between volcanic islands (platform facies volcanic-limestone type). Based on the field map-ping and stratigraphic section data, seven rift-related sedimentary facies were recognized and a depo-sitional model for volcanic island was proposed. It is revealed that some volcanic island chain formed quickly and intermittently in the Qamdo Block during violent eruption, and small carbonate reef, shoal, platform occurred above or on edge of volcanic island, and some slope sedimentary facies surrounded volcano island chain during dormant period of volcanic activities. Three types of fusulinid assemblages were distinguished in the carbonate rocks, which deposited in varied positions of a palaeo-volcanic island: (1) Misellina-Schwagerina assemblage occurred above or on edge of volcanic island, (2) Para-fusulina assemblage was located at restricted depression facies among volcanic islands or carbonate platform, and (3) the reworked Pseudofusulina-Schwagerina assemblage occurred at slope facies near margin of volcanic island, which originally deposited in the shallow-water carbonate platform, then collapsed along the volcanic island margin with fusulinid-bearing grain-supported carbonate con-glomerate or calcirudite, and finally re-deposited on the deeper slope. The sedimentary sequen

关键词： volcanic rocks sedimentary facies depositional model fusulinid Permian Qinghai

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The Norian megalodontid fauna in Qinghai-Tibet Plateau,western China

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Science China Earth Sciences 2012年第10期55卷 1620-1626页

作者： YAO HuaZhou ZHANG RenJie SHA JingGen WANG JianXiong niu zhijun DUAN QiFa Wuhan Institute of Geology and Mineral Resources China Geological Survey Wuhan 430223 China Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China

Many well-preserved silicified megalodontids found from the Jiapila Formation of the Upper Triassic in western China show great variations in the amorphous teeth and the massive hinge plate,making the internal molds vary greatly in size and ***,the internal molds of megalodontids do not always provide reliable taxonomic *** a result,about 3/4 of the 132 species and 6 of 9 genera of Triassic Megalodontidae erected on the basis of internal molds have to be *** revised definitions of genera Neomegalodon,Triadomegalodon,and Conchodon are given in this paper.

关键词： Qinghai-Tibet Plateau western China Norian megalodontids

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Jurassic rocks,bivalves,and depositional environments of the source area of the Yangtze River,Qinghai Province,western China

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Science China Earth Sciences 2011年第8期54卷 1136-1148页

作者： YAO HuaZhou ZHANG RenJie DUAN QiFa SHENG XianCai niu zhijun WANG JianXiong ZENG BoFu WU JianHui Wuhan Center of Geological Survey China Geological Survey Wuhan 430223 China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China Institute of Exploration and Development Jianghan Petroleum Administration Bureau Qianjiang 443124 China Hubei Vocational College of Land and Resources Jingzhou 434000 China

Jurassic rocks are abundantly developed in the source area of the Yangtze River,South Qinghai,with the greatest thickness of 6311 m,including five stratigraphic units:Qoimaco Formation,Buqu Formation,Xiali Formation,Suowa Formation,and Xueshan *** on sufficient fossils of bivalves,ammonites,and brachiopods,the major part of these formations is ascribed to the Middle Jurassic Bathonian to *** diagnostic fossils have been found from the Lower Qoimaco Formation or Upper Xueshan Formation,which could possibly contain in part Bajocian and Oxfordian taxa respectively.

关键词： Source area of Yangtze River Jurassic rocks bivalves depositional environments

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Latest Wuchiapingian to Earliest Triassic Conodont Zones and δ13 Ccarb Isotope Excursions from Deep-Water Sections in Western Hubei Province, South China

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Journal of Earth Science 2019年第5期30卷 1059-1074页

作者： Bo Yang Hanxiao Li Paul B. Wignall Haishui Jiang zhijun niu Qian Ye Qiong Wu Xulong Lai School of Earth Sciences China University of Geosciences Wuhan 430074 China Wuhan Center of Geological Survey Wuhan 430205 China School of Earth & Environment University of Leeds Leeds LS2 9JT UK State Laboratory of Geobiology and Environmental Geology China University of Geosciences Wuhan 430074 China Non-ferrous Metals Geological Exploration Bureau of Zhejiang Province Shaoxing 312000 China State Laboratory of Paleontology and Stratigraphy Nanjing Institute of Geology and Paleontology Nanjing 210008 China

Deep-water facies sections have advantages of recording complete information across the Permian-Triassic boundary(PTB). Here we present a detailed study on the conodont biostratigraphy and carbon isotope profile ranges from the Wuchiapingian-Changhsingian boundary(WCB) to the PTB of two deep-water facies sections at Zhuqiao and Shiligou in the Middle Yangtze region, western Hubei, South China. Fifteen species and three genera are identified. Eight conodont zones are recognized which in ascending order are the Clarkina orientalis, C. wangi, C. subcarinata, C. changxingensis, C. yini, C. meishanensis, Hindeodus parvus and Isarcicella isarcica zones. The onset of deposition of the deep-water siliceous strata of Dalong Formation in western Hubei began in the Late Wuchiapingian and persisted to the Late Changhsingian. Carbon isotope negative excursions occur near both the WCB and PTB in both sections. The WCB δ13 Ccarb negative excursion is in the C. orientalis and C. wangi zones. The PTB δ13 Ccarb negative excursion began in the C. yini Zone and extended to the I. isarcica Zone. The absence of several Changhsingian zones may indicate the difficulty of extracting conodonts from siliceous strata or the presence of an intra-Changhsingian hiatus.

关键词： Dalong Formation conodonts δ13Ccarb isotope Wuchiapingian-Changhsingian boundary Permian-Triassic boundary

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The Silurian A-Type Granites in Northeastern Guangxi,South China Block:New Evidence of Transition from Compression to Post-orogenic Extension of the Kwangsian Orogen

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Acta Geologica Sinica(English Edition) 2016年第5期90卷 1913-1914页

作者： JIA Xiaohui WANG Xiaodi TANG Gongjian YANG Wenqiang niu zhijun Wuhan Center of Geological Survey China Geological Survey State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of Sciences

Objective More and more evidence suggests that the Kwangsian orogen is probably an intraplate orogen, which is one of the few examples of intraplate orogenesis worldwide. However, the initiation time, size and scope of the Kwangsian orogeny have not been determined yet. This study analyzed the Silurian A-type granites in northeastern Guangxi, South China Block, which may provide new evidence for the transition from compression to post- orogenic extension of the Kwangsian orogen.

关键词： The Silurian A-Type Granites in Northeastern Guangxi South China Block

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青海南部二叠纪■类生物古地理区系

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地球科学（中国地质大学学报） 2015年第2期40卷 346-356页

作者：牛志军吴俊武汉地质矿产研究所湖北武汉430223

冈瓦纳与欧亚大陆间的昌都地块构造属性存在争议,解决问题的关键是生物古地理区系判别.青海南部二叠纪类化石群的研究表明昌都地块该生物群一直表现为暖水的特提斯型,与华南地区始终表现出更多的相似性,其生物古地理归属应为特提斯大区... 详细信息

冈瓦纳与欧亚大陆间的昌都地块构造属性存在争议,解决问题的关键是生物古地理区系判别.青海南部二叠纪类化石群的研究表明昌都地块该生物群一直表现为暖水的特提斯型,与华南地区始终表现出更多的相似性,其生物古地理归属应为特提斯大区华夏-特提斯区华南亚区.昌都地块南界龙木错-双湖-澜沧江缝合带在早二叠世为划分青藏高原暖水型特提斯区的南界,不仅是华南亚区与藏北冷暖混合亚区的分界线,也是特提斯大区与冈瓦纳大区的分界线.中二叠世以后该带不再构成大区界线,但在确定次一级分区界线上仍是一个很好的划分标志;北界金沙江缝合带二叠纪两侧生物群表现出一致性,未形成浅海底栖生物自由迁移的障碍,不具有生物古地理分区意义.

关键词：昌都地块二叠纪 ■类古生物地理地理分布地层学

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Contemporary crustal deformation of the Chinese continent and tectonic block model

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Science China Earth Sciences 2003年第z2期46卷 25-40页

作者： WANG Min (王敏) SHEN Zhengkang (沈正康) niu zhijun (牛之俊) ZHANG Zusheng (张祖胜) SUN Hanrong (孙汉荣) GAN Weijun (甘卫军) WANG Qi (王琪) REN Qun (任群) Center for Earthquake Analysis and Prediction China Seismological Bureau Beijing 100036 China Crustal Deformation Research Center Institute of Geology China Seismological Bureau Beijing 100029 China Department of Earth and Space Sciences University of California Los Angeles CA 90095-1567 USA Crustal Deformation Research Center Institute of Geology China Seismological Bureau Beijing 100029 China First Crustal Deformation Monitoring Center China Seismological Bureau Tianjin 300180 China Center for Earthquake Analysis and Prediction China Seismological Bureau Beijing 100036 China Crustal Deformation Research Center Institute of Geology China Seismological Bureau Beijing 100029 China Institute of Seismology China Seismological Bureau Wuhan 430071 China Crustal Deformation Research Center Institute of Geology China Seismological Bureau Beijing 100029 China

We obtain the preliminary result of crustal deformation velocity field for the Chinese con-tinent by analyzing GPS data from the Crustal Motion Observation Network of China (CMONOC), particularly the data from the regional networks of CMONOC observed in 1999 and 2001. We de-lineate 9 tectonically active blocks and 2 broadly distributed deformation zones out of a denseGPS velocity field, and derive block motion Euler poles for the blocks and their relative motionrates. Our result reveals that there are 3 categories of deformation patterns in the Chinese conti-nent. The first category, associated with the interior of the Tibetan Plateau and the Tianshan oro-genic belt, shows broadly distributed deformation within the regions. The third category, associatedwith the Tarim Basin and the region east of the north-south seismic belt of China, shows block-likemotion, with deformation accommodated along the block boundaries only. The second category, mainly associated with the borderland of the Tibetan Plateau, such as the Qaidam, Qilian, Xining(in eastern Qinghai), and the Diamond-shaped (in western Sichuan and Yunnan) blocks, has thedeformation pattern between the first and the third, i.e. these regions appear to deform block-like,but with smaller sizes and less strength for the blocks. Based on the analysis of the lithosphericstructures and the deformation patterns of the regions above, we come to the inference that thedeformation modes of the Chinese continental crust are mainly controlled by the crustal *** crust of the eastern China and the Tarim Basin is mechanically strong, and its deformationtakes the form of relative motion between rigid blocks. On the other hand, the northward indentation of the Indian plate into the Asia continent has created the uplift of the Tibetan Plateau and the Tianshan Mountains, thickened their crust, and raised the temperature in the crust. The lower crust thus has become ductile, evidenced in low seismic velocity and high elect

关键词： GPS, continental crustal motion, tectonic blocks, significance test.

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直流电动机装配质量检测方法

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电机与控制应用 2012年第12期39卷 38-40页

作者：牛志钧永济新时速电机电器有限责任公司山西永济044502

较系统地介绍了直流电动机整机装配质量的检测控制方法,包括了整机装配、电机刷握等分度、转轴轴锥面等方面检测评价方法。提出了提高电动机装配质量的注意事项。

关键词：直流电动机装配刷握等分度轴锥接触面

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湘中地区南华系沉积序列、物源特征及区域对比

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地球科学 2019年第9期44卷 3074-3087页

作者：宋芳牛志军何垚砚杨文强中国地质调查局武汉地质调查中心湖北武汉430205 中国地质大学地质调查研究院湖北武汉430074 中国地质调查局古生物与生命.环境协同演化重点实验室湖北武汉430205

新元古代晚期湘中地区为扬子地台向盆地过渡的区域,是进行南华系地层对比的重要研究区.通过对宁乡菜花田及桃源马金洞剖面的测制并结合区域地质资料,厘定研究区南华系地层沉积序列为长安组、富禄组(局部地区顶部为古城组)、大塘坡组、... 详细信息

新元古代晚期湘中地区为扬子地台向盆地过渡的区域,是进行南华系地层对比的重要研究区.通过对宁乡菜花田及桃源马金洞剖面的测制并结合区域地质资料,厘定研究区南华系地层沉积序列为长安组、富禄组(局部地区顶部为古城组)、大塘坡组、南沱组(洪江组),宁乡菜花田剖面为长安组出现的北界.在宁乡菜花田剖面长安组底部取得的碎屑锆石最年轻一组锆石谐和年龄为752.5±4.2 Ma(n=3,MSWD=2.4),可限定长安组沉积下限不早于760 Ma,碎屑锆石年龄谱显示长安组物源来自扬子地台.对比沉积特征并结合已发表的研究成果,认为长安组为明确的冰期地层,沉积下限可对应Sturtian冰期,区域上古城组冰期沉积可作为富禄组顶部,与下伏长安组一起构成一个冰期→间冰期→冰期的沉积体系,共同组成Sturtian冰期在区域上的沉积记录.由于冰期的阶段性和区域性,沉积显示在各地有所不同;大塘坡组是温暖气候下的间冰期沉积,南沱组/洪江组代表了一次分布范围很广的冰期,对应Marinoan冰期.虽然由于缺少同位素年龄的卡定,大塘坡组之下的地层精细对比还有待新的研究材料支撑,但Sturtian冰期在华南的多次沉积响应对认识当时古气候及早期生命演变历史仍有重要意义.

关键词：湘中地区南华系沉积序列物源碎屑锆石地层学

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中扬子地区南华纪早期碎屑锆石U-Pb年龄及其对物源特征和古地理格局的约束

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地质学报 2016年第10期90卷 2661-2680页

作者：宋芳牛志军何垚砚杨文强中国地质调查局武汉地质调查中心武汉430205 中国地质调查局古生物与生命-环境协同演化重点实验室武汉430205 中国地质大学(武汉) 武汉430074

南华纪早期中扬子地区以鄂中古陆为主体,在其周缘发育以莲沱组为代表、以河流相为主的沉积。本文通过对湖北通山、长阳以及湖南杨家坪3个地区代表性剖面的莲沱组及相应层位碎屑锆石年龄谱的研究,结合研究区已发表的相关成果,对中扬子地... 详细信息

南华纪早期中扬子地区以鄂中古陆为主体,在其周缘发育以莲沱组为代表、以河流相为主的沉积。本文通过对湖北通山、长阳以及湖南杨家坪3个地区代表性剖面的莲沱组及相应层位碎屑锆石年龄谱的研究,结合研究区已发表的相关成果,对中扬子地区不同地理位置南华纪早期物源特征及其对古地理格局的约束进行探讨。根据研究区碎屑锆石年龄谱~810Ma、~860Ma、~2000Ma及~2500Ma的年龄峰值,认为其物源为典型的亲扬子型,主要物源区为鄂中古陆的隆起剥蚀区;>3000Ma的崆岭杂岩物源只分布于宜昌莲沱、长阳以及随州大洪山地区,在该线南东方向应存在一个地势较低的区域。

关键词：碎屑锆石中扬子南华纪物源特征古地理格局

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