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Metamorphism of the East Sector of the Southern Qinling Orogenic Belt and Its Geological Significance

Acta Geologica Sinica(English Edition) 1999年第1期73卷 65-77页

作者： WEI Chunjing YANG Chonghui ZHANG Shouguang Department of geology Peking University Beijing 100871 Institute of geology Chinese Academy of Geological Sciences Beijing 100037

The east sector of the southern Qinling belt is, lithologically, composed mainly of metapelites, ***qüartzites, marbles and small amount of metabasites and gneisses, whose protoliths are the Silurian, Devonian and less commonly the Sinian and Upper Palaeozoic. They have been subjected at least to two epochs of metamorphism. The early epoch belongs to progressive metamorphism which is centered on high amphibolite-granulite fades in the Fuping area and changed outwards into low amphibolite facies (staurolite-kyanite zone), epidote amphibolite facies (garnet zone) and greenschist facies (chlorite and biotite zones), the metamorphic age of which is about 220–260 Ma. This early-epoch metamorphism belongs to different pressure types: the rocks from greenschist to low amphibolite facies belong to the typical medium-pressure type which shows geothermal gradients of about 17–20 ***C/km and was probably produced by a crustal thickening process related to continental collision, and the high amphibolite-granulite facies belongs to the low-pressure type which shows geothermal gradients of about 25–38 ***C/km and was probably affected by some magmatic heats. Based on the basic characteristics of the P-T paths of the different facies calculated from the garnet zonations, it can be deduced that the metamorphism of medium-pressure facies series took place during an imbricated thickening process, rather than during the uplifting process after thickening. The late-epoch metamorphism belongs to dynamic metamorphism of greenschist facies which is overprinted on the early-epoch metamorphic rocks and is Yanshanian or himalayan in age, probably related to intracontinental orogeny.

关键词： metamorphism metamorphic minerals P-T conditions and paths east sector of the southern Qinling orogenic belt

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Seismic Sedimentology Study in the High-Resolution Sequence Framework——A Case Study of Platform Margin Reef-Beach System of Changxing Formation,Upper Permian,Yuanba Area,Northeast Sichuan Basin,China

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Journal of Earth Science 2012年第4期23卷 612-626页

作者：陈雷陆永潮郭彤楼邢凤存焦养泉 Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of Geosciences Southern Exploration and Development division Company of SINOPEC Institute of Sedimentary geology Chengdu University of Technology State Key Laboratory of Oil/Gas Reservoir geology and Exploitation Chengdu University of Technology Faculty of Earth Resources China University of Geosciences

The Yuanba （元坝） area is considered another potential large-scale reef-bank gas field following the Puguang （普光） field. However, there are lots of difficulties on the spatial and temporal distribution of reef-beach and the detailed prediction of the effective reservoir in the sequence stratigraphic framework. In this paper, based on the seismic data, well, log and core, we conduct a high-resolution sequence division and build an isochronal sequence stratigraphic framework for the Changxing （长兴） Formation by the methods of wavelet transformation, FMI, etc.. Then, the corresponding relationship among the lithologic facies, logging facies, seismic facies, seismic attribute facies and reservoir of Changxing Formation were established through well-seismic calibration and geological-geophysical modeling. Furthermore, detailed study on the spatial and temporal distribution of microfacies of the reef-beach was carried out by means of seismic attribute extraction. Meanwhile,combined with impedance inversion, the spatial distribution of porosity of reef-beach reservoir was predicted. The results show that the revolution of the reef-beach system contains three stages which are initial bioclastic bank establishment stage, reef development stage and exposure stage. Also, porosity inversion shows that the region with high value of porosity is located in the reef cap, fore reef and back *** Sedimentology Study in the High-Resolution Sequence Framework

关键词： seismic sedimentology platform margin reef-beach system Changxing Formation,Yuanba area Northeast Sichuan basin.

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Discovery and prediction of high natural gamma sandstones in Chang 73 Submember of Triassic Yanchang Formation in Ordos Basin, China

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Journal of Central South University 2019年第7期26卷 1840-1855页

作者： ZHENG Qing-hua LIU Xing-jun YOU Ji-yuan BAI Yun-yun WANG Jing-hui CHEN Xiao-liang School of Chemistry & Chemical Engineering Yulin University Yulin 719000 China Changqing division China Petroleum Well Logging Limited Company Xi’an 710201 China Department of geology Northwest University Xi’an 710069 China

The large scale development of high natural gamma sandstones has been discovered in the Chang 73 Submember of the Triassic Yanchang Formation in the Ordos Basin, China. High natural gamma sandstones consist of terrigenous detrital rocks with particle sizes ranging from silt to sand. They represent turbidite deposits characterized by high gamma ray values that are more than 180 American Petroleum Institute (API) units on a natural gamma ray log profile. For a long time, very high natural gamma sandstones had been identified as high-quality source rocks, such as oil shales, from conventional well log profiles, such as natural gamma ray well logs. Therefore, predicting the distribution of high natural gamma sandstones was studied. The sedimentary, lithological, and well log characteristics, as well as the genesis of the high radioactivity of high natural gamma sandstones were analyzed in the Chang 73 Submember. Thorium (Th), uranium (U) and other radioactive elements were found, carried by deep hydrothermal activity, and probably resulted in the formation of a relatively high radioactive zone in the cross-section, where high natural gamma sandstones usually develop in large quantities. This caused many turbidite sand bodies, which should have a continuous distribution in the cross-section, to appear to have a discontinuous distribution, when using conventional well log profiles, such as natural gamma ray well logs. From the above mentioned apparent discontinuous distribution of turbidite sand bodies in the cross-section, a continuous distribution can be predicted. It is obvious that the prediction of areas of continuous turbidite sand bodies in the cross-section usually corresponds with areas where high natural gamma sandstones are developed in large quantities. Exploration and development practice demonstrated that the developed method is fast and effective in predicting high natural gamma sandstones in the Chang 73 Submember.

关键词： Ordos Basin Chang 73 Submember high-quality source rock high natural gamma sandstone prediction

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The mapping methods and division of tectonic units of the regional tectonic map in the eastern China seas and adjacent regions

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Acta Oceanologica Sinica 2009年第4期28卷 57-64页

作者： YIN Yanhong ZHANG Xunhua WEN Zhenhe GUO Zhenxuan Qingdao Institute of Marine geology Qingdao 266071 China

The geological-geophysical map series of the eastern China seas and adjacent region （1：1 000 000） will be published in the late half year of 2009. The regional tectonic map is one of the main professional maps. The Mapping methods, the division method of geological tectonic units and the main geological tectonic units are mainly discussed. The strata from Pliocene to Holocene are peeled off so as to display the Pre-Pliocene structures. In basins, isopaches are drawn for the Cenozoic deposits. The plate tectonic theory and present tectonic pattern are adopted as the priorities in tectonic division. As to the division of intraplate tectonic units, it is a revision, complement and improvement of previous dividing systems, and the nomenclature for each tectonic unit follows the current system in China. The first-order tectonic unit is plate （Pacific Plate, Eurasian Plate and Philippine Sea Plate）. The second-order tectonic unit is tectonic domain （East Asian continental tectonic domain,East Asian continental margin tectonic domain and west Pacific tectonic domain）. The Philippine Sea Plate and the west part of the Pacific Plate are called the West Pacific tectonic domain. The part of the Eurasian Plate involved in this study area can be further divided into East Asian continental tectonic domain and East Asian continental margin tectonic domain. The East Asian continental margin domain is composed of the Ryukyu island arc, the Okinawa Trough back-arc basin and the back-arc basin of Sea of Japan. The East Asian continental tectonic domain in this study area is composed of the Sino-Korea Massif, the Changjiang River （Yangtze） Massif and South China Massif. In turn, these massifs consist of basins, folded belts or uplift zones. The basins,the folded belts or the uplift zones are further divided into uplifts and depressions made up of sags and swells.

关键词： regional tectonic map eastern China seas geological tectonic units division

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Permeability differences based on three-dimensional geometrical information of void spaces

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 368-376页

作者： Dae-Sung Cheon Manabu Takahashi Taehyun Kim geology division Korea Institute of Geoscience and Mineral ResourcesDaejeonSouth Korea Hydrology Research Group National Institute of Advanced Industrial Science and TechnologyTsukubaJapan Radwaste Disposal Research division Korea Atomic Energy Research InstituteDaejeonSouth Korea

In this study,the permeabilities of Berea and Otway sandstones were measured under different confining pressures,and porosity was investigated through mercury intrusion porosimetry(MIP).The total porosities of the Berea and Otway sandstones were approximately 17.4%and 25%,*** size distributions of each sandstone were almost the same,but the pores in the Otway sandstone were slightly ***,the permeability of the Otway sandstone was smaller than that of the Berea sandstone by one order of ***-dimensional(3D)void geometry and geometrical properties of the void spaces relevant to flow were compared to obtain the relation between the permeability differences and porosities of the two *** 3D geometrical analysis using microfocus X-ray computed tomography(CT)was performed,and the pore geometries of both sandstones were compared using the 3D medial axis(3DMA)*** and throat radii,pore coordination number,tortuosity,number of connecting paths,connecting path volume,and other factors were determined using *** Otway sandstone was characterized by a small effective throat/pore radius *** on the fluid flow mechanism,the lower effective throat/pore radius ratio results in a lower permeability induced by the fluid energy loss,which means that the 3D geometrical shape of void spaces affects the permeability value.

关键词： X-ray computed tomography(CT) Porosity Permeability Geometrical information Three-dimensional medial axis(3DMA)

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New paleomagnetic data confirm a dual-collision process in the Himalayas

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National Science Review 2015年第4期2卷 395-396页

作者： Wenjiao Xiao Institute of geology and Geophysics Chinese Academy of Sciences

The India–Asia collision and continual plate convergence have created the himalayan–Tibetan Orogen,which is the youngest and most spectacular continent–continent collision belt on Earth,and thus an ideal place for the study of continent–continent collisions[1,2].Although a large number of geological and geophysical investigations

关键词： data Asia Figure

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New early Eocene vertebrate assemblage from western India reveals a mixed fauna of European and Gondwana affinities

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Geoscience Frontiers 2016年第6期7卷 969-1001页

作者： Thierry Smith Kishor Kumar Rajendra S.Rana Annelise Folie Floreal Sole Corentin Noiret Thomas Steeman Ashok Sahni Kenneth D.Rose Directorate Earth and History of Life Royal Belgian Institute of Natural Sciences29 rue VautierB-1000BrusselsBelgium Wadia Institute of himalayan geology 33 General Mahadeo Singh RoadDehradun248001UttarakhandIndia Department of geology H.N.B.Garhwal UniversitySrinagar246175UttarakhandIndia Scientific Heritage Survey Royal Belgian Institute of Natural Sciences29 rue VautierB-1000BrusselsBelgium Department of geology University of Namur61 rue de BruxellesB-5000NamurBelgium Research Unit Palaeontology Ghent UniversityKrijgslaan 28158B-9000GhentBelgium Centre of Advanced Study in geology Panjab UniversityChandigarh160014India Center for Functional Anatomy and Evolution Johns Hopkins University School of MedicineBaltimoreMD21205USA

The Ypresian Cambay Shale Formation at Vastan and Mangrol lignite mines in Gujarat, western India, has yielded a rich vertebrate fauna with numerous taxa of European affinities. Here we report a new, approximately contemporary vertebrate assemblage from two fossiliferous layers in the nearby mine of Tadkeshwar. These layers have yielded a similar mammal fauna with the co-occurrence of the perissodactyl-like cambaytheriid Cambaytherium thewissi, the adapoid primates Marcgodinotius indicus and cf. Asiadapis cambayensis, and the hyaenodontid lndohyaenodon raoi. The presence of these species in both Vastan and Tadkeshwar mines and at different levels suggests that the deposits between the two major lignite seams represent a single land mammal age. Apart from the aforementioned species there is a new, smaller species of Cambaytherium, and a new genus and species of esthonychid tillodont. This fauna also contains the first large early Eocene vertebrates from India, including an unidentified Coryphodon-like pantodont, a dyrosaurid crocodyliform and a new giant madtsoiid snake. Among the Tadkeshwar vertebrates several taxa are of Gondwana affinities, such as Pelomedusoides turtles, dyr- osaurids, and large madtsoiids, attesting that the early Eocene was a crucial period in India during which Laurasian taxa of European affinities co-existed with relict taxa from Gondwana before the India-Asia collision. Our results suggest that terrestrial faunas could have dispersed to or from Europe during episodes of contact between the Indian subcontinent and different island blocks along the northern margin of the Neotethys, such as the Kohistan Ladakh island-arc system. Gondwana taxa might represent remnants of ghost lineages shared with Madagascar, which reached the Indian subcontinent during the late Cretaceous; alternatively they might have come from North Africa and passed along the southern margin of the Neotethys to reach the Indian subcontinent. These dispersals would have been

关键词： Vertebrates Snakes Mammals Primates Cambay Shale Formation Ypresian

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The Global Stratotype Section and Point （GSSP） for the base of the Katian Stage of the Upper Ordovician Series at Black Knob Ridge, Southeastern Oklahoma, USA

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Episodes 2007年第4期30卷 258-270页

作者： Daniel Goldman Stephen A. Leslie Jaak Nōlvak Seth Young Stig M. Bergstroem Warren D. Huff Department of geology University of Dayton 300 College Park Dayton Ohio 45469 USA Deparment of geology and Environmental Science James Madison University MSC 6903 Harrisonburg VA 22807 USA Institute of geology at Tallinn University of Technology Ehitajate tee 5 19086 Tallinn Estonia School of Earth Sciences Division of Geological Sciences The Ohio State University 155 S. Oval Mall Columbus Ohio 43210 USA Department of geology University of Cincinnati Cincinnati Ohio 45221 USA.

The Global Boundary Stratotype Section and Point （GSSP） for the Katian Stage of the Upper Ordovician Series is defined as the 4.0 m-level above the base of the Bigfork Chert in the Black Knob Ridge section, southeastern Oklahoma. This point in this section is coincident with the first appearance of the graptolite Diplacanthograptus caudatus, which has proved to be a reliable datum for precise worldwide correlation. The FAD ofD. caudatus occurs very near the first occurrences of the graptolites D. lanceolatus, *** americanus, Orthograptus pageanus, O. quadrimucronatus, Dicranograptus hians, and Neurograptus margaritatus. This rapid succession of fossil species appearance events provides a secure basis for identification of the base of the Katian Stage of the Upper Ordovician Series and for its global chronostratigraphic correlation.

关键词：层形断面奥陶纪俄克拉荷马州美国地质特点

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Thalassinoides Ichnofabrics of Lower Cambrian Longwangmiao Formation(Stage 4,Toyonian)on the Yangtze Platform,South China:Improving Paleoenvironmental Interpretations

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Acta Geologica Sinica(English Edition) 2023年第1期97卷 243-255页

作者： TANG Ruifeng ZHANG Jizhi DU Yao WEN Siying ZHONG Bo JIANG Huachuan Institute of Sedimentary geology Chengdu University of TechnologyChengdu 610059China State Key Laboratory of Oil and Gas Reservoir geology and Exploitation Chengdu University of TechnologyChengdu 610059China Exploration division of PetroChina Southwest Oil&Gasfield Company Chengdu 610041China State Key Laboratory of Oil and Gas Reservoir geology and Exploitation Southwest Petroleum UniversityChengdu 610500China School of Geoscience and Technology Southwest Petroleum UniversityChengdu 610500China

An analysis of Thalassinoides ichnofabrics in the Cambrian Stage 4 Longwangmiao Formation from six sections near Chonqing in the Middle and Upper Yangtze Block of South China was conducted to promote the understanding of the paleoenvironment of this *** ichnofabrics are divided into three types according to their morphology,bioturbation index,abundance and related parameters:banded,mottled and *** completeness of the ichnofabrics gradually increases from banded to grid,the scale of the burrows expands,and the structure transitions from twodimensional to ***,phyllocarids and enteropneusts are the most likely *** findings reveal that frequent changes in paleoenvironmental conditions are the dominant factors for generating the various Thalassinoides *** changes in depositional rate,substrate properties and nutrient levels affect the behavior and building patterns of the burrowers,thus leading to the diversity of Thalassinoides *** the lower Longwangmiao Formation beds,many incomplete Thalassinoides burrow systems were built in the substrates with terrigenous detrital minerals,revealing significant environmental pressure on the ***,the Thalassinoides burrows went into complete three-dimensional *** the end of the stage,bioturbation almost disappeared,which indicates that burrowers were finding it difficult to survive in the harsh environment.

关键词： ichnology invertebrate paleontology Thalassinoides carbonate platform paleoenvironment Toyonian

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Characteristics and dynamic analysis of the February 2021 long-runout disaster chain triggered by massive rock and ice avalanche at Chamoli, Indian Himalaya

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第2期15卷 296-308页

作者： Tiantian Zhang Yueping Yin Bin Li Xiaojie Liu Meng Wang Yang Gao Jiawei Wan Kaushal Raj Gnyawali Institute of Geomechanics Chinese Academy of Geological SciencesBeijing100081China China Institute of Geological Environment Monitoring China Geological SurveyBeijing100081China College of geology Engineering and Geomatics Chang’an UniversityXi’an710100China Sichuan Geological Survey Institute Chengdu610081China Natural Hazards Section Himalayan Risk Research Institute(HRI)Bhaktapur44800Nepal

A massive rock and ice avalanche occurred on the western slope of the Ronti Gad valley in the northern part of Chamoli,Indian Himalaya,on 7 February 7,*** avalanche on the high mountain slope at an elevation of 5600 m above sea level triggered a long runout disaster chain,including rock mass avalanche,debris avalanche,and *** disaster chain had a horizontal travel distance of larger than 17,600 m and an elevation difference of 4300 *** this study,the disaster characteristics and dynamic process were analyzed by multitemporal satellite *** results show that the massive rock and ice avalanche was caused by four large expanding discontinuity *** disaster chain was divided into five zones by satellite images and field observation,including source zone,transition zone,dynamic entrainment zone,flow deposition zone,and flood *** entrainment effect and melting water were recognized as the main causes of the long-runout *** on the seismic wave records and field videos,the time progress of the disaster was analyzed and the velocity of frontal debris at different stages was *** total analyzed disaster duration was 1247 s,and the frontal debris velocity colliding with the second hydropower station was approximately 23 m/*** study also carried out the numerical simulation of the disaster by rapid mass movement simulation(RAMMS).The numerical results reproduced the dynamic process of the debris avalanche,and the mechanism of long-runout avalanche was further verified by parametric ***,this study discussed the potential causes of disaster and flood and the roles of satellite images and seismic networks in the monitoring and early-warning.

关键词： Rock and ice avalanche Disaster chain Long-runout Entrainment Flood

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