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Characteristics of the Middle-Late Triassic sedimentary facies assemblages in the Songpan-Ruoergai area

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Progress in Natural Science:Materials International 2007年第3期17卷 305-313页

作者： YAN Zhen, YU Liangjun, LI Jiliang, BIAN Qiantao, WANG Zongqi and YANG Yongcheng ( institute of geology, {2. academy of Geological Sciences, beijing 100037, china state key laboratory of lithospheric evolution, institute of geology and geophysics, {2. academy of Sciences, beijing 10002., china Shaanxi Insititute of geology Survey, Xianyang 712.00, china) [a]institute of geology Chinese Academy of Geological Sciences Beijing China [b]state key laboratory of lithospheric evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China [c]Shaanxi Insititute of geology Survey Xianyang China

The Middle-Late Triassic sedimentary rocks in the Songpan-Ruoergai area mainly consist of calcareous siltstone, muddy limestone, lithic arkose, feldspathic litharenite, mudstone, wormkalk, oolithic limestone, and conglomerate. Except for limestone bed increasing eastward longitudinally and vertically, the calcareous component of the sandstones increases obviously. Abundant benthic and plant fossils and their clasts occur within these rocks. The sedimentary structures predominately contain flaser, parallel, tabular, wavy, and herringbone cross beddings. These data coevally imply that the Middle-Late Triassic sediments deposited in the fluvial, lake and tide environments. Additionally, the rocks display graded, parallel, hummocky beddings, and sandy lamination, a feature characteristic of storm deposits.

关键词： Middle-Upper Triassic fluvial-lake environments tide environment tempestite Songpan-Ruoergai

Kinematics and dynamics of the Mesozoic orogeny and late-orogenic extensional collapse in the Sino-Mongolian border areas

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Science china Earth Sciences 2005年第7期48卷 849-862页

作者： ZHENG Yadong 1 & WANG Tao2.1. key laboratory of Orogenic Belts and Crustal {2. (Peking University), Ministry of Education, beijing 100871, china 2. institute of geology, chinese academy of Geological Sciences, beijing 100037, china key laboratory of Orogenic Belts and Crustal {2. (Peking University) Ministry of Education Beijing 100871 China institute of geology Chinese Academy of Geological Sciences Beijinq 100037 China

The Sino-Mongolian border areas underwent two important tectonic events during Mesozoic time after late Paleozoic orogeny: a late Triassic to earlier Jurassic contractional event that resulted in a large-scale south-vergent thrust during the orogeny and a late Jurassic-earlier Cretaceous extensional event in a north-south direction that formed a metamorphic core complex. The kinematic and dynamic analyses show that the thrust sheet moved southwards with a kinematic vorticity number of ca. -0.10 and sub-horizontal maximum compressive stress axis that belongs to a contraction-thickening shear. The upper plate of the late-orogenic detachment relatively moved in a 165°direction. The average kinematic vorticity in its earlier stage was 0.74 that belongs to simple shear dominated shearing and related to the maximum compressive stress axes dipping at ～66°, while the later average kinematic vorticity was ～0.55°that belongs to pure shear dominated shearing with sub-vertical maximum compressive stress axes. This suggests that the thrusting led to the crust thickened and the lower plate rocks that were originally located in the upper crust depressed through a brittle-ductile transition zone into the lower crust and became warmer. The heated rocks trended to uplift since their increasing volume and decreasing density while the loading of the upper-plate rocks increased due to the structural thickening. Under the combined effect of the loading and the thermal-uplifting, the ductile shear zone in between increased in its component of vertical pure shear. Once its pure-shear component exceeded its simple-shear one the ductile shear zone became an extension-thinned shear zone. This progressive transitional process reflects internal and essential temporal and spatial relationships: the extensional factor nucleated during the crust thickening by thrusting and increase of the extensional factor finally led to late-orogenic collapse.

关键词： Mesozoic thrusting,late-orogenic collapse,kinematic vorticity number,stress state.

Petrology and mineral chemistry of new ureilites found in Grove Mountains, Antarctica

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Progress in Natural Science:Materials International 2008年第4期18卷 431-439页

作者： Bingkui Miaoa,b,, Yangting Linb, Guiqin Wangc, Daode Wangc, Ziyuan Ouyangd a key laboratory of Geological Engineering Center of Guangxi Province, Guilin University of Technology, Guilin 541004,{2. b state key laboratory of lithospheric evolution, institute of geology and geophysics, chinese academy of Sciences, beijing 10002.,{2. c key laboratory of Isotope Geochronology and Geochemistry, Guangzhou institute of Geochemistry, chinese academy of Sciences, Guangzhou 510640,{2.d National Astronomical Observatories, chinese academy of Sciences, beijing 100012.{2. key laboratory of Geological Engineering Center of Guangxi Province Guilin University of Technology Guilin 541004 China state key laboratory of lithospheric evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China key laboratory of Isotope Geochronology and Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

Petrography and mineral chemistry of two new ureilites, GRV 02.512.and 02.931, from the Grove Mountains, Antarctica, are reported in this paper. GRV 02.512.exhibits a typical ureilite texture, and consists of 48.3% olivine, 9.4% pigeonite and 38.1% carbo- naceous interstitial material and/or reduction product. GRV 02.931 has a cataclastic porphyritic texture, and consists of 19.1% olivine and 14.1% pigeonite embedded in 66.3% carbonaceous interstitial material and/or reduction product. The coarse-grained olivine and pigeonite in both meteorites have homogeneous cores, and they are FeO-rich within the range of the ferroan subgroup (subgroup I) of olivine-pigeonite ureilites. All olivine grains of the meteorites show reduction zones along boundaries and cracks. Abundant diamond coexists with graphite as graphite-rich patches and veins in the carbonaceous interstitial material. Petrogenesis of both meteorites and the origin of diamond are discussed.

关键词： Meteorite Achondrite Ureilite Diamond Antarctica

Megaripples from the Mesoproterozoic of the Kimberley region,northwestern Australia and its geological implications

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Journal of Palaeogeography 2012年第1期1卷 15-25页

作者： Lan Zhongwu 1,2,3,,Zhong-Qiang Chen 2,4,1.state key laboratory of lithospheric evolution,institute of geology and geophysics,chinese academy of Sciences,beijing 10002.,china 2.School of Earth and Environment,The University of Western Australia,Australia 3.key Lab of Petroleum Resources Research,institute of geology and geophysics,chinese academy of Sciences,beijing 10002.,china 4.state key laboratory of Biogeology and Environmental geology,china University of Geosciences (Wuhan),Wuhan 430074,china state key laboratory of lithospheric evolution Institute of Geology and Geophysics Chinese Academy of Sciences School of Earth and Environment The University of Western Australia key Lab of Petroleum Resources Research Institute of Geology and Geoph

Large ripples are described from the Mesoproterozoic Hilfordy Formation in the Kimberley region,northwestern *** ripple index (RI) and ripple symmetry index (RSI) suggest the Kimberley ripples were likely generated by storm *** wave height is up to 15 2. cm and wave length is up to 70 90 *** features,incorporated with other morphological characteristics such as symmetry,steepness,ripple spacing,and compositions,agree well with the megaripples previously reported from the intertidal-nearshore settings of modern seas and the geological *** Mesoproterozoic ripples were likely generated by the storm-induced *** survey of the global record of megaripples reveals that such structures have occurred through the geological past from the Archean to present *** were particularly common in the Neoproterozoic and had the largest ripple length and ripple height among the modern and geological *** is probably because extreme storms prevailed at that *** frequent occurrence in present day beach is probably due to the prevalence of extreme storms caused by the monsoon or tsunami/earthquake influenced climatic regimes.

关键词： megaripples palaeohydrodynamics extreme storms Mesoproterozoic Hilfordy Formation Kimberley northwestern Australia

Petrology and ^(40)Ar/^(39)Ar iso-topic ages of blueschists in Gangmar, central Qiangtang, northern Tibet

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chinese Science Bulletin 2001年第5期46卷 423-427页

作者： DENG Xiguang, DING Lin, LIU Xiaohan & ZHOU Yonglaboratory of lithospheric Tectonic {2., institute of geology and geophysics, chinese academy of Sciences, beijing 10002., china laboratory of lithospheric Tectonic {2. Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

The petrology and mineral assemblages of blueschists in the Gangmar, central Qiangtang, northern Tibet were examined, which indicates that the metamorphic condition is high-pressure low-temperature. In this note, we reported the 40Ar/39Ar dating results of glaucophane from two blueschist samples. Their apparent ages are (2.5.0±1.3) Ma and (2.7.6±2.3) Ma and similar isochron ages are (2.5.0±0.9) Ma and (2.2.4±0.8) Ma, respectively. These iso-topic datings show the high-pressure metamorphism occurring in Lower Permian. The ages also coincide with the evolution of Palaeo-Tethys ocean in Late Palaeozoic.

关键词： glaucophane blueschist 39Ar/40Ar age Palaeo-Tethys Gangmar northern Tibet.

Digital image analysis of palaeoenvironmental records and applications

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chinese Science Bulletin 2002年第23期47卷 1957-1963,2025-2026页

作者： SUN Donghuai1,2. LIU Yu2.& TAN Ming31. South china Sea institute of Oceanology, {2. academy of Sciences. Guangzhou 510301, china 2. state key laboratory of Loess and Quaternary geology, Earth Environmental institute, {2. academy of Sciences, Xi’an 710075, china 3. institute of geology and geophysics, {2. academy of Sciences, beijing 10002., china South china Sea institute of Oceanology Chinese Academy of Sciences Guangzhou China state key {2. of Loess and Quaternary geology Earth Environmental Institute Chinese Academy of Sciences Xi’an China institute of geology and {2. Chinese Academy of Sciences Beijing China

Environmental change signals in geological or biological records are commonly reflected on their reflecting or transmitting images. These environmental signals can be extracted through digital image analysis. The analysis principle involves section line selection, color value reading and calculating environmental proxy index along the section lines, layer identification, auto-chronology and investigation of structure evolution of growth bands. On detailed illustrations of the image technique, this note provides image analyzing procedures of coral, tree-ring and stalagmite records. The environmental implications of the proxy index from image analysis are accordingly given through application demonstration of the image technique.

关键词： digital image environmental records.

Two new species of Vestrogothia (Phosphatocopina, Crustacea) of Orsten-type preservation from the Upper Cambrian in western Hunan, South china

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Science china Earth Sciences 2009年第6期52卷 784-796页

作者： ZHANG HuaQiao1,2.& DONG XiPing1,2.1 School of Earth and Space Sciences,Peking University,beijing 100871,china 2.{2. key laboratory of Palaeobiology and Stratigraphy,Nanjing institute of geology and Palaeontology,chinese academy of Sciences,Nanjing 2.0008,china School of Earth and Space Sciences Peking University Beijing 100871 China state key {2. of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China

Although fossils of Orsten-type preservation represented by Skaracarida and Phosphatocopina were first reported from the Middle and Upper Cambrian in western Hunan, South china in 2.05, diversified phosphatocopine species have never been appropriately described and elucidated in terms of their evolutionary relationships. Here, we described two new species of Phosphatocopina, Vestrogothia anterispinata sp. nov. and V. bispinata sp. nov. The evolutionary relationship among all the valid species of Phosphatocopina is discussed and the phylogeny of Phosphatocopina is reestablished using cladistic analysis. Accordingly, phosphatocopines primitively evolved along two lineages: one evolved towards the emergence of lobes; the other evolved towards the emergence of dorsal spines. Respectively, lobes originated independently three times, and dorsal spines originated only once. With regard to the dorsal rims, interdorsum originated first, whereas dorsal furrow originated independently twice on the basis of interdorsum. Probably Hesslandona may represent a polyphyletic group, whereas Vestrogothia a monophyletic group.

关键词： fossils of Orsten-type preservation Vestrogothia Phosphatocopina Crustacea evolution phylogeny Cambrian Hunan

Geomorphologic evidence of phased uplift of the northeastern Qinghai-Tibet Plateau since 14 million years ago

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Science china Earth Sciences 2004年第9期47卷 822-833页

作者： LU Huayu1, WANG Xiaoyong1, AN Zhisheng1, MIAO Xiaodong1, ZHU Rixiang3, MA Haizhou2. LI Zhen4, TAN Hongbing2.& WANG Xianyan1 1. state key {2. of Loess and Quaternary geology, institute of Earth Environment, chinese academy of Sciences, Xi’an 710075 china 2. Qinghai institute of Salt Lakes, chinese academy of Sciences. Xining 810008, china 3.{12., chinese academy of Sciences, beijing 10002., china 4. Department of Geography, Qinghai Normal University, Xining 810008, china chinese Acad Sci Inst Earth Environm State Key Lab Loess & Quaternary Geol Xian 710075 Peoples R China chinese Acad Sci Qinghai Inst Salt Lakes Xining 810008 Peoples R China chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China Qinghai Normal Univ Dept Geog Xining 810008 Peoples R China

A typical sequence of fluvial terraces and aeolian deposits overlying these ter- races were multidisciplinary investigated. New evidences for uplift process of the northeastern Qinghai-Tibetan Plateau in the past 14 million years were obtained. At least 11 river terraces along Huangshui, the first-class tributary of Yellow River, at the Xining-Huzhu region are identi- fied. While the first one (T1) is classified as an accumulation terrace, the others are all basement river terraces, which consist of the Tertiary sandstone and siltstone bedrock, fluvial gravel and pebbles and the overlying aeolian loess-Red Clay deposit. Samples from the aeolian deposits were examined for paleomagnetic stratigraphic reconstruction (1030 samples), luminescence dating (16 samples), magnetic susceptibility and grain-size distribution (more than 4000 sam- ples). The luminescence dating and stratigraphic correlation suggest that terraces of Tll, T10, T8, T7, T3, T2. T1 were formed at 14, 11.3, 1.55, 1.2. 0.15, 0.07 and 0.01 million years ago, re- spectively. Sedimentological analysis and geomorphological observation indicate that formation and evolution of these terraces were mainly driven by tectonic uplift. Therefore, the terrace se- quence provides an ideal geological record, of the uplift process of the northeastern during the past 14 million years, and the timings of the terraces formation are regarded as the timings of tectonic uplift. The significant uplifting events took place at 14, 11.3, 1.2.and 0.15 mil- lion years ago, respectively. The fluvial incision at the Xining-Huzhu region is less than 100 m during a period of ~12.million years in the Miocene era (between the Tll and T9), while the Huangshui River had incised 432.m during the past 1.2.million years (from T7 to the present floodplain). The river incision process clearly demonstrates that accelerated rising of the north- eastern Qinghai-Tibet Plateau during the late Cenozoic, and provides new evidence of previous thoughts

关键词： river terrace, tectonic uplift, loess-Red Clay, the past 14 million years, northeastern Qinghai-Tibet Plateau.

A zooarchaeological study of bone assemblages from the Ma'anshan Paleolithic site

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Science china Earth Sciences 2010年第3期53卷 395-402页

作者： ZHANG Yue1,2.3, WANG ChunXue1,2. ZHANG ShuangQuan1,2.& GAO Xing1,2.1 institute of Vertebrate Paleontology and Paleoanthropology, chinese {2. of Sciences, beijing 100044 2.Joint laboratory of Human evolution and Archaeometry, chinese {2. of Sciences, beijing 100044 3 state key laboratory of Palaeobiology and Stratigraphy, Nanjing 2.0008 1. institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China2. Joint Laboratory of Human Evolution and Archaeometry Chinese Academy of Sciences Beijing 100044 China3. State Key Laboratory of Palaeobiology and Stratigraphy Nanjing 210008 China

Ten thousands of bone fragments were recovered from the Ma’anshan Paleolithic site, of which 4358 pieces can be identified to skeletal elements or species. In this research, the bone assemblages are quantified based on elements of MNI, MNE, and MAU. Then bone surface modifications and skeletal element profiles of the bone assemblages are studied to understand shlepping behaviors and reveal the technique of disarticulating and defleshing the animals’ bodies, etc. Based on the analyses of bone assemblages and the comparative study with the ethnoarchaeological as well as experimental data, it is assumed that later hominids at the site made fuller use of the game animals than the earlier hominids. Incorporating the lines of evidence from chronological dating, paleoenvironment, and polished bone tools between the two cultural layers, here we propose three hypotheses suggesting that the changes of environment, the migrations of the hominids from the North, or the demographic pulses may cause such a behavioral difference. However, it is yet to be determined which hypothesis can better explain the changes.

关键词： Ma’anshan site zooarchaeology Paleolithic hominid behavior