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Genetic Mechanism of Mineral Inclusions in Zircons from the Khondalite Series, Southeastern Inner Mongolia

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Acta Geologica Sinica(English Edition) 2003年第1期77卷 28-35页

作者： LIU Fulai and SHEN Qihan institute of {1., Chinese {2. of geological sciences, beijing 1.0037 Chinese Acad Geol Sci Inst Geol Beijing 100037 Peoples R China

The early Precambrian khondalite series is widely distributed in theJining-Zhuozi-Fengzhen-Liangcheng area, southeastern Inner Mongolia. The khondalite series mainlyconsists of sillimanite garnet potash feldspar (or two-feldspar) gneiss and garnet biotiteplagioclase gneiss. These gneissic rocks have commonly experienced granulite-facies metamorphism. Inzircons separated from sillimanite garnet potash feldspar gneisses, many mineral inclusions,including Sil, Grt, Ky, Kfs, Qtz and Ap, have been identified by the Laser Raman ***, prograde metamorphic mineral inclusion assemblages such as Ky + Kfs + Qtz + Ap and Ky +Grt + Kfs + Qtz are preserved in the core of zircon, while peak granulite-facies metamorphicminerals including Sil + Grt + Kfs + Qtz and Sil + Gif + Kfs + Qtz + Ap are identified in the mantleand rim of the same zircon. However, in some zircons are only preserved the peak metamorphicminerals such as Sil + Grt + Kfs + Qtz and Sil + Grt + Kfs + Qtz + Ap from core to rim, and inothers are inherited the primary cores with minor mineral inclusions of Kfs + Qtz, with peakmetamorphic mineral inclusions around the inherited cores. These data indicate that the mineralassemblage evolution of sillimanite garnet potash feldspar gneisses in the study are did experiencea polymorphic transformation of kyanite to sillimanite. In garnet biotite plagioclase gneisses,secondary electron microscopic images reveal that most zircons display distinct zoning textures,which comprise cores and rims, each with distinctive inclusion assemblages. The inherited mineralinclusions, mainly consisting of Kfs + Pl + Qtz, Kfs + Qtz and Kfs + Qtz + Ap, are preserved in theprimary cores, while peak granulite-facies mineral asemblages, including Grt + Bt + Pl + Qtz + Ap,Grt + Bt + Pl + Qtz and Grt + Bt + Pl + Qtz + Rt, are identified on the rims. The occurrence of peakmetamorphic mineral inclusions in zircons indicates that these gneissic rocks, includingsillimanite garnet potas

关键词： mineral inclusion zircon Laser Raman secondary electron microscopy genetic mechanism khondalite series Inner Mongolia

Northernmost paleo-tethyan oceanic basin in Tibet:Geo-chronological evidence from ^(40)Ar/^(39)Ar age dating of Dur'ngoi ophiolite

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Chinese Science Bulletin 2001年第14期46卷 1203-1205页

作者： CHEN Liang, SUN Yong, PEI Xianzhi, GAO Ming, FENG Tao, ZHANG Zhongqing & CHEN Wen1. Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, china 2. Department of geology, Northwest University, Xi’an, 710069, china 3. institute of geology, Chinese academy of geological sciences, beijing, 1.0037, china Laboratory of Continental Dynamics Northwest University Xi’an China Department of geology Northwest University Xi’an China institute of {1. Chinese Academy of Geological Sciences Beijing China

Whole rock 40Ar/39Ar age dating has been conducted on a basalt sample from Dur’ngoi ophiolite, Qinghai Province, which was reported to be the northernmost pa-leo-tethyan oceanic basin in Tibet. A high temperature pla-teau age (345.3±7.9 Ma) with an isochorn age (336.6±7.1.Ma) has been obtained, representing the eruption time of oceanic crust Considering related geological settings, the new age provides constraints on the northernmost pa-leo-tethyan suture zone in Tibet and the tectonic evolution of Paleo-tethys in Northeast Tibet and adjacent areas.

关键词： Dur’ngoi ophlolite 40Ar -39Ar age Paleo-tethys.

Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

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Science china Earth {1. 2005年第10期48卷 1672-1677页

作者： YANG Gang1,2. DU Andao1, LU Jiren3, QU Wenjun1 & CHEN Jiangfeng2.1. National Research Center of Geoanalysis, beijing 1.0037, china 2. Laboratory for Earth Material Cycling, School of Earth and Space {2., University of Science and Technology of china, Hefei 2.002., china 3. institute of Mineral Resource, Chinese academy of geological {2., beijing 1.0037, china National Research Center of Geoanalysis beijing{1. Laboratory for Earth Material Cycling School of Earth and Space Sciences University of Science and Technology of China Hefei China institute of Mineral Resource Chinese {1. of {2. sciences beijing china

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 833 ± 35 Ma, initial 1.7Os/1.8Os ratio of 0.2.9 ± 0.01. (MSWD = 1.7) and γOs = 1.0 ± 1. is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 82. ± 8 Ma (n=5, MSWD = 4.3). The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 1.%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, ICP-MS.

Mesozoic-Cenozoic tectonic transition in Kuqa Depression-Tianshan,Northwest china:Evidence from sandstone detrital and geochemical records

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Science china Earth {1. 2005年第9期48卷 1387-1402页

作者： LI Zhong1. GUO Hong2. WANG Daoxuan3 & LIN Wei1.1. {1. of geology and Geophysics, Chinese {2. of sciences, beijing 1.002., china 2. Tarim Oilfield Branch, CNPC, Korla 841.00, china 3. Hefei University of Industry, Tunxilu 1.3, Hefei 2.0009, china 1. institute of {1. and Geophysics Chinese Academy of Sciences 100029 Beijing Chin 2. Tarim Oilfield Branch CNPC 841000 Korla China 3. Hefei University of Industry Tunxilu 193 230009 Hefei Chin

Similar to compositional evolution of sandstone modes and detrital heavy minerals from different profiles in the Kuqa Depression, Northwest china, major element analysis of whole sandstones from the same profiles shows four discontinuous depositional interfaces or periods, respectively corresponding to Lower Triassic\Middle Triassic, Upper Jurassic\Lower Cretaceous, Lower Cretaceous\Paleogene and Miocene\Pliocene, and indicates five-phase evolution during Mesozoic-Cenozoic: (1. From the first to fifth phase, a depositional suite changes from maroon and coarse clastic, through grey-dark grey and fine, red and coarse, red-mottled, interlayered by gypsum, to brown and coarse clastic assemblages, accompanying detrital component evolution in unstable-stable-unstable-very unstable-very unstable assem- blages. It is indicated that carbonate and complex detritus gradually dominate in sandstones in post-Late Jurassic, with rapid reduction of compositional maturity. ({1. For major element geo- chemical parameters of whole sandstones, CaO and Fe{1.O * 3+MgO contents show a change sequence in high-low-high-higher-highest values, with rapid increasing in post-Late Jurassic. (3) Contra some aggregative indicators for weathering indexes of sandstone detrital component, Al{1.3/(CaO+Na{1.) and ln(Q/(L+CE)), show a change sequence in low-high-low-lower-lowest ratios, with rapid decreasing in post-Late Jurassic. It is found that sandstone samples of the first, second and later three phases may be distinguished from the A-CN-K and A-CNK-FM diagrams respectively. Therefore, in the Kuqa Depression-Tianshan, the most important discontinuous depositional interface recording paleotectonic and paleoclimatic transition occurred in Early Triassic\Middle Triassic and Late Jurassic\Early Cretaceous, respectively, and, however, tec- tonic differentiations of basin-range system finally result in distinct depositional systems but similar detrital weathering indexes across the Lower Cretaceous\Paleogene

关键词： Tianshan, Kuqa Depression, basin-range, depositional record, tectonic transition, Mesozoic-Cenozoic.

Vermiform trace fossils from the Precambrian Ruyang Group, western Henan

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Chinese Science Bulletin 1997年第3期42卷 251-254页

作者： HU Jianmin, MENG Qingren and LI Wenhou1.Xi’ an College of geology, Xi’an 71.054,{1. 2. {2. of Geophysics, Chinese academy of sciences, beijing 1.01.1.{1. 3 Department of geology, Northwest University, Xi’an 71.069,{1. Xi’an College of geology Xi’an China institute of Geophysics Chinese Academy of Sciences Beijing China Department of geology Northwest University Xi’an China

THE origin and evolution of Precambrian lives has been a long-standing controversial problem. It is now generally accepted by most paleontologists that the origin of metazoa can be traced back to more than 1.00 Ma, because the Ediacara and latest pre-Ediacara fauna, such as the Huainan fauna, are featured by their diversification of forms, complicated structures

关键词： Precambrian trace fossil Ruyang Group.

“Tali Glaciation” on Massif Diancang

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Science china Earth {1. 2007年第11期50卷 1685-1692页

作者： YANG JianQiang1, CUI ZhiJiu2. YI ChaoLu1, SUN JiMin3 & YANG LiRong3 1 institute of Tibetan Plateau Research, Chinese academy of {2., beijing 100085, china 2.College of Environmental {2., Peking University, beijing 100871, china 3 institute of geology and Geophysics, Chinese academy of {2., beijing 10002., china 1. institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China 2. College of Environmental {1. Peking University Beijing 100871 China 3. institute of {1. and Geophysics Chinese Academy of Sciences Beijing 100029 China

The term of ''Tali Glaciation'' is nominated from Massif Diancang in Yunnan Province. The confusing process of the term''s being put forward is confirmed through literature checking. Based on several times of field trip, the glacial landforms in this region are studied in detail, and the magnitude of the glaciation was determined. According to the numerical ages from TL, AIMS ^(1.)C and OSL dating, the earliest glacial advance on Massif Diancang occurred at 30—40 ka BP, followed by the advances at the last stage of the last glaciation, the late glacial and neoglations in turn, until glaciers vanished at 1.2.1.5 ca. a BP in this region. It can be concluded that glaciers were limited above 3600 m a.s.l., and no glaciers existed on the lower part and adjacent mountains since the last glaciation.

关键词： Massif Diancang,Tali Glaciation,glacial landform,glaciation sequence,numerical dating

A new method for spatio-temporal prediction of rainfall-induced landslide

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Science china Earth {1. 2006年第4期49卷 421-430页

作者： DING Jixin1,2. YANG Zhifa2. SHANG Yanjun2. ZHOU Shenghua1 & YIN Juntao3 1. china Non-ferrous Metals Resource geological Survey, {2. 100012. china 2. institute of geology and Geophysics, Chinese academy of sciences, Key Laboratory of Engineering Geomechanics, {2. 10002., china 3. School of Geoscience & Environmental Engineering, Central South University, Changsha 410083, china 1. china Non-ferrous Metals Resource {1. Survey Beijing 100012 China 2. institute of geology and Geophysics Chinese Academy of Sciences Key Laboratory of Engineering Geomechanics Beijing 100029 China 3. School of Geoscience & Environmental Engineering Central South University Changsha 410083 China

geological condition and rainfall are two most principal conditions inducing landslides in the Chongqing region. By analyzing the forming conditions of rainfall-induced landslides, a new method for spatio-temporal prediction of rainfall-induced landslide is brought forward on the basis of grading and overlapping geological condition and rainfall factor in this paper. At first, semi-quantitative assessment and grading for the geological condition of a certain area or slope can be carried out with the multi-factor interactive matrix. Then the severity of rainfall in that area is grading according to the maximum daily rainfall and the total rainfall in a rainfall course. Finally, the “landslide probability judgement factor” can be worked out through grading and overlapping “geological condition influenc- ing factor” and “rainfall influencing factor”, by which the landslide can be graded into 4 grades, they are landslide extremely easily happening, landslide easily happening, landslide difficultly happening and landslide hardly ever happening respectively. More accurate spatio-temporal prediction of rain- fall-induced landslides can come true on the ground of detailed geological survey of some dangerous slopes in an area and more precise weather forecast. Finally, the reliability and feasibility of carrying out the spatio-temporal prediction of rainfall-induced landslides with the method of “two factors” grading and overlapping are validated by the example of Jipazi landslide.

关键词： rainfall-induced landslide, geological condition, rainfall, two factors, grading and overlapping, interactive matrix, spatio-temporal prediction.

The history of crustal uplift and metamorphic evolution of Panzhihua-Xichang micro-palaeoland, SW china:Constraints on Sm-Nd, ^(40)Ar/^(39)Ar and FT ages of granulites

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Science china Earth {1. 2004年第8期47卷 689-703页

作者： XU Shijin1. LIU Wenzhong1. WANG Rucheng1. YU Hangbo1. LI Daming2. WAN Jinglin2.& FANG Zhong1.1. Department of Earth sciences and State Key Laboratory for Mineral Deposits Research, Nanjing University, Nanjing 2.0093, china {2., china Seismological Bureau, beijing 1.002., china 1. Department of Earth sciences and State Key Laboratory for Mineral Deposits Research Nanjing University 210093 Nanjing China 2. institute of geology China Seismological Bureau 100029 Beijing China

Panzhihua-Xichang (Panxi) micro-palaeoland is the oldest terrane on the western margin of the Yangtze Block. Some intermediate-basic granulites are considered to be the crys-talline basement of lower crust in the terrane. Granulite-facies metamorphism of the granulites was developed in the period from 1.86 Ma to 1.2. Ma. The origin of granulites was related to the collision orogenic process occurring when the micro-palaeolands merged to form the Rodinia Supercontinent. Amphibolite-facies retrogressive metamorphism of granulites took place in the period from 877 Ma to 82. Ma. This period was consistent with the breakup time of the Rodinia Supercontinent. 40Ar/39Ar ages and fission track (FT) ages of granulites in the Panxi mi-cro-palaeoland show that the vertical movement history of crustal rocks was a slow uplift process of the rigid terrane in the time from Neoproterozoic to Mesozoic. The subduction of India Plate towards Euroasia Plate resulted in the rapid uplift of the Qinghai-Tibetan Block in Cenozoic. Meanwhile, the Qinghai-Tibetan Block moved towards east. Consequently the Panxi terrane was uplifted rapidly. As a result of the collision orogeny between the Qinghai-Tibetan Block and the Panxi terrane, the granulite-facies crystalline basement in this region was exhumed and exposed to the surface.

关键词： granulite,isotope geochronology,crustal uplift movement,Panzhihua-Xichang region,western margin of Yangtze Block.

Characteristics and origins of primary fluids and noble gases in mantle-derived minerals from the Yishu area,Shandong Province,china

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Science china Earth {1. 2006年第1期49卷 77-87页

作者： MA Jinlong1,2. TAO Mingxin2.3 & YE Xianren2.1. Resources and Environmental School, Lanzhou University, Lanzhou 730000, china 2. Key Laboratory of Gas Geochemistry, institute of {2. and Geophysics, Chinese academy of sciences, Lanzhou 730000, china 3. College of Resources Science & Technology, beijing Normal University, beijing 100875, china 1. Resources and Environmental School Lanzhou University Lanzhou 730000 China 2. Key Laboratory of Gas Geochemistry Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou 730000 China 3. College of Resources Science & Technology Beijing Normal University Beijing 100875 China

Fluids and noble gases of mantle-derived materials are important tracers forthe mantle information. Compositions of primary fluids and noble gases in mantle-derived mineralsfrom the Yishu area, Shandong Province, china, were tested by the methods of heat-bursting andheat-melting respectively. The fluids are mainly composed of CO_{1. CO and H_{1. which account forabout 90% of the total, and are similar to the mantle-derived rocks from other areas of easternchina; ratios of ~3He/~4He in almost all samples range from 0.8{1.Ra to {1.74 Ra, whereas^(40)Ar/^(36)Ar from {1.9.5 to 758.8. Both ranges are much lower than those of the typical oceanmantle-derived samples (such as MORB) and primarily reflect the influences of the atmosphericcomponents and the radiogenic isotopes. Ratios of C/~3He range from {1..6 x 1.~9 to 1.50 x 1.~9,N_{1.Ar from 9{1. to 5661.1. and N_{1.~3He from {1.5 x 1.~9 to {1. x 1.~9, similar to those in westernUnited States and New Zealand which belong to the tectonic plate collision regions. The ratios fallin the intersect of mantle-crust-atmosphere in the comprehensive tracer-charts, reflecting theinfluences of the atmosphere and the crusts with organic components. Our results suggest that thecomposition of the primary fluids and the isotopic ratios of the noble gases may either reflect theevolution process of mantle-derived rocks connected with the rise and eruption of magma, or theinfluence of the ancient subduction-plate on the continental mantle of this region.

关键词： noble gases, primary fluids, mantle-derived minerals, Yishu area.