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Possible impact event in the Late Cambrian

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Global Geology 2007年第1期10卷 78-82页

作者： O.A.Korchagin S.V.Dubinina V.A.Tsel'movich i.i.pospelov Geological institute Russian Academy of SciencesMoscow 109017Russia Geophysical Observatory Borok-Branch of institute of Physics of the Earth Russian Academy ofSciencesBorokRussia

The repeated investigation of the Batyrbay section has been done by the authors. Today we see in- creasing of interest to revising of volumes and boundaries of Stages and Series in the Cambrian and Ordovician, as well as to the events of this time. in this work the description of iron spherules and particles, found in the deep-water limestone layer of the conodont Cordylodus prirnitivus Zone in the middle Upper Cambrian of the Batyrbay section, Malyi Karatau of South Kazakhstan, and formed during the time of global sea-level changes known as a world-wide Lange Ranch Eustatic event, have been done. From our point of view, finds of iron spherules and particles may evidence about new unknown yet Event of cosmic origin, i.e. falling of a meteorite on Earth in the middle Late Cambrian.

关键词： Batyrbay Kazakhstan Upper Cambrian spherules iron meteorite event

东昆仑南带中元古代晚期—新元古代早期叠层石组合的发现

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东昆仑南带中元古代晚期—新元古代早期叠层石组合的发现

Discovery of Ordovician acri-tarchs in Buqingshan ophio-lite complex, East Kunlun Mountains and its significance

中国科学院地质与地球物理研究所2006学术年会

作者：边千韬朱士兴 i.i.pospelov M.A.Sem ikhatov 孙淑芬陈代钊那春光中国科学院地质与地球物理研究所中国地质调查局天津地质矿产研究所 Geological institute Russian Academy of SciencesMoscow 109017Russia

东昆仑南带加嗡门地区碳酸盐岩地层中发现的中元古代晚期2新元古代早期叠层石组合以大型锥叠层石及其相关的分子Conophy ton garganicus ***,C ***,Jacutophy ton f.和Conicodom enia f.等最丰富,并与Baicalia共生,故可视之为Conophyton... 详细信息

东昆仑南带加嗡门地区碳酸盐岩地层中发现的中元古代晚期2新元古代早期叠层石组合以大型锥叠层石及其相关的分子Conophy ton garganicus ***,C ***,Jacutophy ton f.和Conicodom enia f.等最丰富,并与Baicalia共生,故可视之为Conophyton—Baicalia组合。该叠层石组合可以与天山和华北等地蓟县系中部—青白口系中部叠层石组合对比,尤其酷似于天山地区蓟县系的爱尔基干组合和华北蓟县系的闪坡岭叠层石组合,而显著有别于华南地块。它还可以与南乌拉尔、西伯利亚、北美、北非和阿拉斯加半岛等地区的中里菲界上部—上里菲界下部层位中的叠层石组合对比。加嗡门叠层石组合的时限为距今1 300～850Ma,大致为蓟县纪中期—青白口纪中期或中里菲晚期—晚里菲早期。东昆仑南带存在前寒武纪微地块,当时此微地块的古地理和古环境与天山、华北、西伯利亚和阿拉斯加半岛等地区的前寒武纪地块相似,均位于低纬度区,其上均广泛发育适宜叠层石繁育的温暖陆表海,它们可能共同处于罗迪尼亚超大陆的低纬度大陆边缘部位,与华南地块的不同。这对本区和东昆仑地层和大地构造研究,以及对罗迪尼亚超大陆重建提供了新的古生物约束。

关键词：叠层石中元古代晚期—新元古代早期罗迪尼亚超大陆东昆仑

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Chinese Science Bulletin 2001年第4期46卷 341-345页

作者： i.pospelov O.Astrakhantsev N.Chamov institute of Geology and Geophysics Chinese Academy of Sciences Beijing China Nanjing institute of Geology and Paleontology Chinese Academy of Sciences Nanjing China Tianjin institute of Geology and Mineral Resources Chinese Academy of Geological Sciences Tianjin China Geological institute Russian Academy of Sciences Moscow Russia

This note reports the first discovery of Middle-Late Ordovician acritarchs from the Buqingshan ophio-lite complex of the southern ophiolite zone of East Kunlun. The acritarch assemblage is dominated with acanthomor-phids (approx. 32%) and sphaeromorphds (approx. 63%) and contains more characteristic forms, such as Lophos-phaeridium edenense, L. varum, Nothooidium sp.,? Bued-ingiisphaaeridium sp., Visbysphaera sp., Strophomorpha sp., etc. in addition, some tube-like fragments and tetrads, which are recognized as affinity to terrestrial plants and usual occurrence in Late Ordovician-Early Silurian strata, are preserved together with acritarchs. All the known fossil evi-dence indicates that the strata should be Middle-Late Ordo-vician in age. it not only provides paleontological proof for the existence of Ordovician ophiolite, but also challenges the usual ideas on strata composition of the studied area and the southern ophiolite zone of East Kunlun, and the models on tectonic framework and evolution of

关键词： acritarch Ordovician stratum ophiolite complex Bu-qingshan East Kunlun orogen.

Discovery of the Jiawengmen Stromatolite Assemblage in the Southern Belt of Eastern Kunlun, NW China and its Significance

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Acta Geologica Sinica(English Edition) 2005年第4期79卷 471-480页

作者： BiAN Qiantao ZHU Shixing i. i. pospelov M. A. SEMiKHATOV SUN Shufen CHEN Daizhao NA Chunguang institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Tianjin institute of Geology and Mineral Resources China Geological Survey Tianjin 300170 China Geological institute Russian Academy of Sciences Moscow 119017 Russia

This paper reports a newly discovered Late Mesoproterozoic-Early Neoproterozoic stromatolite assemblage, named here the ＂Jiawengmen stromatolite assemblage＂, represented by a Conophyton-Baicalia association in the Jiawenmen area in the southern belt of the Eastern Kunlun. This stromatolite assemblage is dominated by large-scale conical stromatolites and related elements, i.e., Conophyton garganicus var. inkeni, C. cf. ressoti Menchikov, Jacutophyton cf., Conicodomenia f., which commonly co-exist with elements of the group of Baicalia. This assemblage can be correlated with that of the middle Jixian-middle Qingbaikou System in North and Northwest China, but is different from that in South China. Correlation can also be made with that in the upper horizon of the Middle Riphean-lower horizon of the Upper Riphean in the South Ural Mountains and Siberia of Russia, in North Africa, and in the Alaskan Peninsula of North America. These facts suggest that the Jiawengmen stromatolite assemblage probably colonized during 1300-850 Ma ago. Accordingly, the stromatolite-bearing carbonate rocks are then proposed to correspond to the middle Jixian System-middle Qingbaikou System or the upper Middle Riphean-lower Upper Riphean. Our stromatolite data further suggest that a Precambrian microblock, named the Xialawen microblock here, occurred in the southern belt of Eastern Kunlun, the western part of the Maqên microblock. Similar stromatolite assemblages in the Maqên microblock and those blocks that occurred in North China, Siberia and North Africa point to similar paleogeographic and paleoenvironmental conditions. These microblock and blocks were probably located at low latitudes and on the continental margins of the Rodinian supercontinent, where warm epicontinental seas were favorable to widespread colonization of stromatolites during the Late Mesoproterozoic-Eady Neoproterozoic. However, these stromatolite assemblages are quite different from those of the South China block, which

关键词： stromatolite Precambrian Rodinia supercontinent Eastern Kunlun Tibetan Plateau

青海省布青山早古生代末期埃达克岩的发现及其构造意义

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岩石学报 2007年第5期23卷 925-934页

作者：边千韬 pospelov i.i. 李惠民常承法李继亮中国科学院地质与地球物理研究所 Geological institute Russian Academy of SciencesMoscow 109017Russia 中国地质调查局天津地质矿产研究所

在青藏高原北部阿尼玛卿蛇绿岩带布青山段首次发现了埃达克岩,它们多呈不规则岩脉状侵入于布青山地区北部早古生代蛇绿混杂岩中。其岩性为花岗-英云闪长岩,主矿物有斜长石、石英、黑云母、角闪石、少量钾长石和辉石;副矿物有榍石、磷灰... 详细信息

在青藏高原北部阿尼玛卿蛇绿岩带布青山段首次发现了埃达克岩,它们多呈不规则岩脉状侵入于布青山地区北部早古生代蛇绿混杂岩中。其岩性为花岗-英云闪长岩,主矿物有斜长石、石英、黑云母、角闪石、少量钾长石和辉石;副矿物有榍石、磷灰石、锆石和磁铁矿等。属钙碱系列,具典型(Ⅰ类、O型、HSA)埃达克岩的地球化学特征,表现为:高SiO_2(63. 65%～71.59%),高Al_2O_3(14.81%～16.11%),高Na_2O(4.68%～5.33%)和Na_2O/K_2O(1.48～3.08,平均2.39),高Sr (444.08×10^(-6)～560.41×10^(-6))和Sr/Y(50.8～105.3),HREE强烈亏损,低Yb(0.38×10^(-6)～0.74×10^(-6)),高La/Yb(44.93～90.97),弱负Eu异常(δEu=0.74～0.90),富集大离子亲石元素(LiLE),亏损高场强元素(HFSE),Ba、Pb正异常而Nb、P负异常。获得布青山埃达克岩的锆石TiMS U-Pb年龄为402±24Ma。布青山埃达克岩熔体来自俯冲的昆祁秦洋壳(含海洋沉积物)在石榴石角闪岩相条件下部分熔融,主要残留相为石榴石(±角闪石)。布青山埃达克岩的发现指示早古生代末期洋壳(昆祁秦多岛洋的一部分)俯冲作用的存在,俯冲方向朝北(现在方位),此前,俯冲带发生长时间的向洋迁移,早古生代末期俯冲带已后退到阿尼玛卿蛇绿混杂岩带以南;暗示典型埃达克岩也可以形成于洋壳俯冲晚期;提示阿尼玛卿蛇绿岩带可能有与典型埃达克岩有关的Au、Ag、Cu、Mo等热液和斑岩矿床。

关键词：埃达克岩地球化学早古生代末期青藏高原阿尼玛卿蛇绿岩带

东昆仑南缘早三叠世洪水川组的源区特征：来自碎屑组成、重矿物和岩石地球化学的证据

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岩石学报 2008年第5期24卷 1068-1078页

作者：闫臻边千韬 Oleg A. Korchagin igor i. pospelov 李继亮王宗起中国地质科学院地质研究所北京100037 中国科学院地质与地球物理研究所北京100029 俄罗斯科学院地质研究所莫斯科119017

分布于东昆仑南缘的早三叠世洪水川组系一套由砾岩、砂岩、页岩和鲕粒灰岩等浅海相和河流相沉积物构成的弧前盆地沉积组合。砂岩碎屑组成、重矿物组合、岩石地球化学和古水流综合研究结果表明,洪水川组砂岩物源主要来自于北侧的岛弧带,... 详细信息

分布于东昆仑南缘的早三叠世洪水川组系一套由砾岩、砂岩、页岩和鲕粒灰岩等浅海相和河流相沉积物构成的弧前盆地沉积组合。砂岩碎屑组成、重矿物组合、岩石地球化学和古水流综合研究结果表明,洪水川组砂岩物源主要来自于北侧的岛弧带,同时南侧的阿尼玛卿蛇绿混杂带也为其形成提供了部分物源;源区主要出露长英质岩石、变质岩和硅质岩。

关键词：早三叠世洪水川组源区背景东昆仑

Lower Permian formations of different geodynamic environments in A'nyemaqen ophiolitic zone (Buqingshan Mts., eastern Kunlun, Qinghai Province, China)

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Journal of Geoscientific Research in Northeast Asia 2005年第1期8卷 15-32页

作者： i. i. pospelov E. Ya. Leven BiAN Qian-tao O. A. Korchagin Geological institute Russian Academy of Sciences Moscow 119017 Russia institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Lower Permian formations within the Buqingshan Mountains （A＇nyemaqen ophiolitic zone, eastem sector of the eastern Kunlun） were formed in the following paleogeodynamic environments （from north to south）：（ 1 ） shelf and slope of a passive continental margin in a marginal sea; （2）partially Permian metamorphic rocks of subduction-accretion complexes and volcanogenic rocks of an ensimatic island arc, of the age limited from above by the Asselian - Sakmarian; and （3） an island are slope and oceanic trench. Subduction-accretion complexes and the island are volcanites are overlain with a sharp angular unconformity by a carbonate-conglomerate sequence, which presents as local molasse of the Early Permian age. Based on fusulinids from the basal limestone, the age of the local molasse is first defined as the Yakhtashian-Bolorian, i.e, Artinskian-Kungurian （？）. The thorough investigations revealed that the initial closure of the eastern Paleotethys within the eastern Kunlun corresponded to the Sakmarian-Yakhtashian （Artinskian） boundary, whereas in the western Paleotethys sector （Northern Pamirs） the closure occurred considerably earlier, prior to the Late Bashkirian. Thus, the idea that the Paleotethys in the eastern Kunlun reached its maximum width in the Permian, is highly questionable. During the Early Permian the A＇nyernaqen branch of the Paleotethys intensely decreased. Beginning from the Bolorian （Kungurian） and up to the end of the Permian this branch represented its relict in the form of a marginal sea depression. it may be suggested that the Paleotethys closure in the A＇nyemaqen took place gradually from the west to the east and covered a long period from the Late Carboniferous to the terminal Early Permian.

关键词： Lower Permian formations ophiolitic zone Paleotethys eastern Kunlun China

Discovery of Ordovician acritarchs in Buqingshan ophiolite complex,East Kunlun Mountains and its significance

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Discovery of Ordovician acritarchs in Buqingshan ophiolite c...

Age,geochemistry and tectonic setting of Buqingshan ophiolites,North Qinghai-Tibet Plateau,China

中国科学院地质与地球物理研究所2001学术年会

作者： i.pospelov O.Astrakhantsev N.Chamov Geological institute Russian Academy of Sciences

This note reports the first discovery of Middle -Late Ordovician acritarchs from the Buqingshan ophiolite complex of the southern ophiolite zone of East Kunlun. The acritarch assemblage is dominated with acanthomor-phids (approx.32%) and sphaeromorphds(approx.63%) and contains more characteristic forms,such as Lophos-phaeridium edenense,***,Nothooidium sp.,? Bued-ingiisphaaeridium sp.,Visbysphaera sp.,Strophomorpha sp., *** addition,some tube-like fragments and tetrads,which are recognized as affinity to terrestrial plants and usual occurrence in Late Ordovician-Early Silurian strata,are preserved together with *** the known fossil evidence indicates that the strata should be Middle-Late Ordovician in *** not only provides paleontologicai proof for the existence of Ordovician ophiolite,but also challenges the usual ideas on strata composition of the studied area and the southern ophiolite zone of East Kunlun,and the models on tectonic framework and evolution of this area and the northern part of the Qinghai-Tibetan Plateau.

关键词： acritarch Ordovician stratum ophiolite complex Buqingshan East Kunlun orogen

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Age,geochemistry and tectonic setting of Buqingshan ophiolit...