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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, china b state key laboratory of lithospheric evolution, institute of geology and geophysics, chinese academy of sciences, beijing 10002., china c key laboratory of Isotope Geochronology and Geochemistry, Guangzhou institute of Geochemistry, chinese academy of sciences, Guangzhou 510640, chinad National Astronomical Observatories, chinese academy of sciences, beijing 100012, china 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 021512 and 022931, from the Grove Mountains, Antarctica, are reported in this paper. GRV 021512 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 022931 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

Characteristics and geological significance of olivine xenocrysts in Cenozoic volcanic rocks from western Qinling

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Progress in Natural Science:Materials International 2006年第12期16卷 1300-1306页

作者： SU Benxun~ 1,2 **, ZHANG Hongfu~1, XIAO Yan~ 1,2 and ZHAO Xinmiao~ 1,2 (1. state key laboratory of lithospheric evolution, institute of geology and geophysics, chinese academy of sciences, beijing 10002., china 2. Graduate School of chinese academy of sciences, beijing 100039, china) [a]state key laboratory of lithospheric evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China [b]Graduate School of chinese academy of sciences Beijing China

Cenozoic volcanic rocks from the Haoti, Dangchang County of the western Qinling Mountains, contain a few clearly-zoned olivines. These olivines are relatively big in grain sizes and usually have cracks or broken features. Their cores have similar compositions （Mg#=90.4-91.0） to those for the peridotitic xenoliths entrained in host volcanic rocks and their rims are close to the compositions of olivine phenocrysts （Mg#=85.5-81.9）. The CaO contents in these zoned olivines are lower than 0.1%. These features demonstrate that the clearly-zoned olivines are xenocrysts and disaggregated from mantle peridotites. The zoned texture was the result of the interaction between the olivine and host magma. Available data show that the volcanic rocks would have been derived from the mantle source metasomatized by subducted hydrathermally-altered oceanic crust. The formation of these Cenozoic volcanic rocks was perhaps related to the rapid uplift of the Tibetan Plateau.

关键词： Western Qinling Dangchang Haoti Cenozoic volcanic rocks olivine xenocrysts zoned texture.

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 evolution, institute of geology and geophysics, chinese academy of sciences, beijing 10002., china laboratory of lithospheric Tectonic evolution 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 (275.0±1.3) Ma and (287.6±2.3) Ma and similar isochron ages are (275.0±0.9) Ma and (282.4±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.

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 23 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

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 evolution (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 evolution (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.

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, chinese academy of sciences. Guangzhou 510301, china 2. state key laboratory of Loess and Quaternary geology, Earth Environmental institute, chinese academy of sciences, Xi’an 710075, china 3. institute of geology and geophysics, chinese academy of sciences, beijing 10002., china South china Sea institute of Oceanology Chinese Academy of Sciences Guangzhou China state key laboratory of Loess and Quaternary geology Earth Environmental Institute Chinese Academy of Sciences Xi’an China institute of geology and geophysics 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.

Reply to the comment by Zhao et ***:“Tectonic evolution of the Hengshan-Wutai-Fuping complexes and its implication for the Trans-North china Orogen”

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Reply to the comment by Zhao et ***:“Tectonic evolution of ...

Reconstruction and interpretation of giant mafic dyke swarms:a case study of 1.78 Ga magmatism in the North china craton

中国科学院地质与地球物理研究所第十届(2010年度)学术年会

作者： Zhihong Wang~* state key laboratory of lithospheric evolution,institute of geology and geophysics,chinese academy of sciences,beijing,10002.,china

*** I welcome the comments by Zhao et al.(2010) on my recent paper dealing with the tectonic evolution of the Hengshan-Wutai-Fuping complexes and its implication for the Trans-North china Orogen(TNCO).This reply gives... 详细信息

关键词： Tectonic vergence Subduction polarity Tectonic setting Neoarchean Wutai granitoids Cordilleran-type orogen

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Reconstruction and interpretation of giant mafic dyke swarms...

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

中国科学院地质与地球物理研究所第十届(2010年度)学术年会

作者： PENG PENG state key laboratory of lithospheric evolution,institute of geology and geophysics,chinese academy of sciences,beijing 10002.,china

Short-lived giant mafic dyke swarms are keys to the interpretation of continental evolution and tectonics,reconstruction of continental palaeogeographical regimes,and petro-genesis of *** 1.78 Ga Taihang-Lvliang dyke swarm,one of the most significant and best-preserved Precambrian swarms in the central part of the North china craton(NCC),is reviewed and *** is interpreted to have a radiating geometry that is compatible with the Xiong’er triple-junction rift,in which the Xiong’er volcanic province is proposed to be the extrusive counterpart of this *** resulted in significant extension,uplift and magmatic accretion of the NCC,and it is comparable with the Phanerozoic large igneous provinces(LIPs) in areal extent(c.0.3 Mkm)and estimated volume(c.0.3 Mkm),short lifespan( china LIP is unique in that it comprises large volumes of both mafic and intermediate *** could have resulted from extensive mantle-crust interaction, probably driven by a large-scale mantle upwelling.A plume tectonic model is favoured by several lines of supporting evidence(*** volcanic flows correlated over large areas and a giant fanning dyke swarm with plume-affinitive chemistry).It could responsible for massive sulphide(Pb-Zn)and gold(Au-Ag)ore deposits in the Xiong’er volcanic province. Dismembered remnants of this magmatism in other block(s),with potential candidates in South America,Australia and India,could identify other cratonic blocks that were formerly connected to the North china craton.

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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 state key laboratory of Palaeobiology and Stratigraphy,Nanjing institute of geology and Palaeontology,chinese academy of sciences,Nanjing 210008,china School of Earth and Space sciences Peking University Beijing 100871 China state key laboratory 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 2005, 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