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Earthquake events in Neoproterozoic and Early Paleozoic and its relationship with supercontinental Rodinia in North China

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Chinese Science Bulletin 2000年第10期45卷 931-935页

作者： Xiufu Qiao linzhi gao Chinese Acad Geol Sci Inst Geol Beijing 100037 Peoples R China

Carbonate liquefied veins in limestone and liquefied mud veins in mudstone are the result by earthquake, which is liquefied in sediments and a strong earthquake event remains clearly records in strata. 24 strata units with earthquake events (molar tooth), which are subdivided into 11 seismic periods, have been distinguished from Mid-Proterozoic to Early Paleozoic strata in the Sino-Korean platform. The distributions of them represent paleo-seismic tectonic zones in different periods, which is tallied with convergent continental block before Proterozoic supercontinental Rodinia and the evidence of the breakup or splitting developed in the inner Sino-Korean Platform in 700 Ma.

关键词： seismites carbonate liquefied veins paleo-Tanlu zone rodinia.

Mesoproterozoic Earthquake Events and Breakup of the Sino-Korean Plate

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Acta Geologica Sinica(English Edition) 2007年第3期81卷 385-397页

作者： QIAO Xiufu gao linzhi PENG Yang Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 School of Earth and Space Sciences Peking University Beijing 100871

In the Mesoproterozoic time, the northern part of the Sino-Korean Plate experienced a period of intensive tectonic extension and breakup. 1. An abundance of sedimentary earthquake records is preserved in the Chuanlinggou, Tuanshanzi and gaoyuzhuang formations in the Mesoproterozoic Changcheng System （1800-1400 Ma） and in the Mesoproterozoic Wumishan Formation of the Jixian System （1400-1000 Ma）. These earthquake records are characterized by various liquefied sand-veins, carbonate microspar and coarser spar veins, limestone dikes, liquefied breccia and various forms of liquefied contorted bedding. This deformation is always associated with synsedimentary faults and igneous activity. 2. Three liquefaction models for soft carbonate sediments are recognized, including liquefaction in laminated carbonate rocks, liquefaction in thin-bedded carbonates and large-scale liquefaction along huge carbonate dikes. 3. Based on the record of earthquake and volcanic activities, the Sino-Korean Plate experienced at least twice intraplate breakups. One occurred between 1800-1400 Ma, and the other occurred at about 1200 Ma. The last breakup resulted in formation of the Yan-Liao aulacogen, a tectonic zone characterized by deeper material vibrancy, active faults, major igneous activity and frequent earthquakes.

关键词： earthquake events Mesoproterozoic Sino-Korean Plate breakup intraplate

Discovery of phosphatized gastrula fossils from the Dou-shantuo Formation,Weng'an,Guizhou Province,China

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Chinese Science Bulletin 2001年第20期46卷 1713-1716页

作者： Yin Chongyu Yue Zhao gao linzhi Institute of Geology Chinese Academy of Geological Sciences Beijing China

Globular fossils from Doushantuo phosphorites at the Weng’an area are for the first time identified as a gas-trulation stage of phosphatized embryos. They are got from the fossiliferous remains after acetic acid maceration. The fossils are found together with formerly reported animal resting eggs and embryos of the earlier cleavage stage. The oblate-shaped fossils with the same size as those reported embryos and invaginate at the middle part into the embryos, show the characteristics of the late blastula to the early gas-trula stage of the embryo development. This discovery convinces the existence of animal embryos at Doushantuo age and offers new facts for the studying of the affinity of related fossils, which are still controversial at present.

关键词： Doushantuo Formation phosphorites gastrulation phosphatization resting eggs embryos.

Neoproterozoic Molar-tooth Structure and Constraint of Depositional Facies and Environment in the North China Platform in Jiangsu, Anhui and Liaoning, Eastern China

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Acta Geologica Sinica(English Edition) 2005年第4期79卷 533-539页

作者： LIU Yongqing gao linzhi LIU Yanxue Institute of Geology Chinese Academy of Geological Sciences Beijing 100037

Molar tooth structure （MTS） represented by complex ptygmatical shapes is widely distributed in the Proterozoic of the world. MTS filled by fine, equant sparry calcite （or dolomite） displays an abrupt contact with hosting rocks, which are mainly composed of carbonaceous micrites and fine-grained carbonates with local silts and stormdominated deposits with graded, cross or wave beddings, numerous erosional surfaces and truncated and fills or guttered bases. Occurrence of MTS suggests a result of the constraint of sedimentary facies, and the storm-base in ramp settings is the maximum depth for the formation of MTS. Vertical succession of MTS-bearing carbonates shows a deposition stacked by high-frequency shallow subtidal and peritidal cycles. An individual cyclic MTS-bearing sequence is characterized by thinning, shallowing and dynamic decreasing-upward, and peritidal caps of purple red iron and organic carbonaceous sediments with more complicated shapes of MTS are common on the top of individual MTS-bearing sequences.

关键词： North China Platform Neoproterozoic Molar-tooth structure carbonate facies and environment

Sand veins and MISS from the Mesoproterozoic black shale (ca. 1.7 Ga) in North China:Implication for methane degassing from microbial mats

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Science China Earth Sciences 2008年第11期51卷 1525-1536页

作者： SHI XiaoYing JIANG GanQing ZHANG ChuanHeng gao linzhi LIU Juan School of Earth Science and Resources China University of GeosciciencesBeijing 100083China State Key Laboratory of Geological Process and Mineral Resources Beijing 100083China Department of Geoscience University of NevadaLas VegasNV 89154-4010USA Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

The Mesoproterozoic Chuanlinggou Formation (ca. 1.7 Ga) consists mainly of dark-gray to black shales that are widespread in the North China Platform. Abundant centimeter-scale sand veins are present within the shale layers of this unit, particularly in the middle part. Sand veins display ptygmatic shapes, perpendicular or with a high angle to bedding planes. They penetrate the black shale layers but are often terminated by thin, lenticular sandstone beds, forming small-scale ‘tepee-like’ structures. On bedding planes, sand veins are expressed as small ridges with 1–3 mm positive relief. Lack of polygonal shapes and their occurrence in thinly laminated, relatively deep-water shales preclude an origin from sand-filled desiccation cracks. Instead, their close association with microbially induced sedimentary structures (MISS) such as micro-wrinkles and gas blisters, putative bacterial fossils (possibly coccoidal cyanobacteria) and framboidal pyrites, suggests that they were formed by degassing of methane from microbial mat decay. Methane gas disrupted overlying sedimentary layers, creating fractures open to seawater. Fine-grained quartz sands, which were transported into the depositional environment by strong winds, filled the fractures. Sand-filled fractures were shortened and folded during burial compaction, forming ptygmatic shapes. The presence of dispersed dolomite and siderite in these sand veins suggests authigenic carbonate precipitation from anaerobic oxidation of methane (AOM). Sand veins are intensely distributed within the Chuanlinggou Formation and are spatially widespread in the North China Platform. If their methane origin is confirmed, they may have important implications for the Mesoproterozoic paleoclimate. With anoxic oceans and low seawater sulfate concentration during the Mesoproterozoic, methane release from microbial mat decay and/or microbial methanogenesis during shallow burial may have been proportionally higher than that of the modern marine e

关键词： sand veins methane degassing microbial mats Chuanlinggou Formation Mesoproterozoic North China Platform

Storm Deposits of the Sinian Zhangqu Formation in Northern Anhui——An Upward Shallowing Carbonate Sequence

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Acta Geologica Sinica(English Edition) 1990年第2期64卷 129-145,234-235页

作者： Qiao Xiufu Xing Yusheng gao linzhi Yin Chongyu Yue Zhao Liu Guizhi Institute of Geology, Chinese Academy of Geological Sciences, Beijing Jia Zhongpeng gao linzhi Chinese Academy of Geological Sciences Beijing

This paper studies. for the first time, the storm deposits of a carbonate sequence in the Sinian ZhangquFormation in northern Anhui. In the formation. a great number of calcareous trider sponge spicules were dis-covered in a distal storm turbidity sequence, which have provided further evidence for the correlation of theSinian Systems in North and South China from a view point of palaeontology.

关键词： Zhang Storm Deposits of the Sinian Zhangqu Formation in Northern Anhui An Upward Shallowing Carbonate Sequence

New material of microfossils from the Ediacaran Doushantuo Formation in the Zhangcunping area, Yichang, Hubei Province and its zircon SHRIMP U-Pb age

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Chinese Science Bulletin 2009年第6期54卷 1058-1064页

作者： LIU PengJu YIN ChongYu gao linzhi TANG Feng CHEN ShouMing Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China

The Zhangcunping area is located at the north limb of the Huangling anticline in Yichang, Hubei Prov-ince. Here, the sedimentary succession of the Ediacaran Doushantuo Formation is similar with that in the Weng'an area, Guizhou Province. A large number of new microfossils (mainly acanthoacritarchs) from the Doushantuo Formation in this area are reported in this paper. The fossil assemblage shows similarity as the phosphatized biota of the Doushantuo Formation at Weng'an, Guizhou Province and the silicified biota of the Doushantuo Formation at the Yangtze Gorges, which suggests that the Zhangcunping area is a key for correlation of the Doushantuo Formation between the Weng'an area, Guizhou Province and the Yangtze Gorges. Besides, a new zircon SHRIMP U-Pb age (614.0±7.6 Ma) is first obtained from a horizon underneath the exposed surface in the middle of the Doushantuo Forma-tion in the Zhangcunping area. This age not only provides a new datum for subdivision of the Ediacaran Doushantuo Formation, but also indicates that the age of the exposed surface in the middle of the Doushantuo Formation in the Yangtze Platform should be posterior to 614.0±7.6 Ma. Due to the horizon of the Weng'an biota situated above the exposed surface, the age of the Weng'an biota should be pos-terior to 614.0±7.6 Ma as well.

关键词：锆石SHRIMP 陡山沱组微体化石湖北省年龄迪卡宜昌 Pb

Earthquake-induced soft-sediment deformation structures in the Mesoproterozoic Wumishan Formation,North China,and their geologic implications

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Science China Earth Sciences 2007年第3期50卷 350-358页

作者： ZHANG ChuanHeng WU ZhengJie gao linzhi WANG Wei TIAN YanLin MA Chao State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesBeijing 100083China Key Laboratory of Lithospheric Tectonics and Lithoprobing Technology Ministry of EducationChina University of GeosciencesBeijing 100083China School of Geosciences and Resources China University of GeosciencesBeijing 100083China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

Soft-sediment structures are key to defining seismites. Two soft-sediment deformation horizons, bounded by undeformed carbonate strata, have been found in the Wumishan Formation in the Jumahe region, 175 km southwest of Beijing. One is in the lowest part of Wumishan Formation; and the other is in the uppermost part of Litho-member I. The soft-sediment structures in these two horizons fall into three categories: mould-and-sag structures, hydraulic shatterings and liquefaction dikes. The mould-and-sag structures are divided into two types: one developed in tidal-flat sediments, accompa-nied by many liquefaction-related structures and characterized by autochthonous post-earthquake sediments in sags, and the other type developed in deep-water environments, is not associated with liquefaction structures, and is overlain immediately by seismogenic tsunamites. The hydraulic shat-terings are composed of pockets of fluidization conglomerate, sand intrusions, and syndepositional faults. The liquefaction dikes fall into two categories: hydraulic-fracturing dikes and lateral-spreading dikes. The former are steep, planar, and pinch out upwards. The latter are snake-like and characterized by no diapir-related drag structures in surrounding rocks. Examination of the attitudes and strati-graphic positions of these structures suggests that these soft-sediment structures are seismogenic, and consequently, are seismites. Most seismites in the Wumishan Formation are developed near the former western, margin fault of Yanliao rift. This occurrence suggests that they could be related to movements on this fault. Other geological implications are discussed.

关键词： Mesoproterozoic Wumishan Formation soft-sediment structures paleo-earthquakes seismites Yanliao rift

Zircon U-Pb dating for the earliest Neoproterozoic mafic magmatism in the southern margin of the North China Block

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Chinese Science Bulletin 2006年第19期51卷 2375-2382页

作者： LIU Yongqing gao linzhi LIU Yanxue SONG Biao WANG Zongxiu Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Beijing SHRIMP Center Beijing 100037 China Institute of Geomechanics Chinese Academy of Geological Sciences Beijing 100081 China

Huge diabase occurs within the Pro- terozoic strata in the southern margin of the North China Block, geographically in the northern parts of Anhui and Jiangsu provinces, where no strata younger than Neoproterozoic have been found. Zir- cons from the diabase show three different structures from cathodoluminesecence imaging, but they are all of magmatic origin. SHRIMP U-Pb dating yields a range of 206Pb/238U ages from 2600 to 124 Ma, but two geological events can clearly be identified from both concordant and discordant ages. One gives two weighted mean 207Pb/206Pb ages of 976 ± 24 and 1038 ± 26 Ma which are interpreted as timing of dia- base crystallization, and the other has a weighted mean 207Pb/206Pb age of 2523 ± 52 Ma that repre- sents formation time of inherited zircon from the old crust. The dating results indicate that the mafic magmatic event occurred in a transition period from the latest Mesoproterozoic to the earliest Neopro- terozoic, consistent with global subduction of Grenvill ocean crust to result in the assembly of superconti- nent Rodinia. Therefore, the North China Block needs to be taken into account when reconstructing the position of China continents within the framework of Rodinia supercontinent.

关键词：华北断块新元古代辉绿岩 U-Pb定年铁镁质岩浆