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Mechanical Research on Biucleus-Type Vortex Structures

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Acta Geologica Sinica(English Edition) 1990年第4期64卷 345-362,462页

作者： Zeng Zuoxun Section of Geomechanics, china university of geosciences, Wuhan, Hubei Fei Zhenbi Section of Geomechanics China University of Geosciences Wuhan Hubei

A new type of vortex structure-binucleus-type vortex structure-is presented in this paper. It is charac-terized by two nuclear columns which distinguish it from uninuclcus-type vorlex structure. The vortical sur-faces of the structure are commonly s-shaped and reversed s-shaped and subordinately of clliptic andhyperbolic shape. and sometimes turbine-like surfaces are observed. On the basis of field structural studies. a mechanical model of rotation around a binuclear column ofcrustal materials is presented in the paper. Burgers viscoelastic solutions of the stress field and deformationfield of this structural type have been obtained using the principle and method of rheology. and simulation ex-periments have been performed. The results of the theoretical calculation and experiments indicate that theproposed mechanical model is applicable.

关键词： Mechanical Research on Biucleus-Type Vortex Structures

The Magma-dynamic Mechaism of Emplacement and Compositional Zonation of the Zhoukoudian Stock, Beijing

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Acta Geologica Sinica(English Edition) 1989年第2期63卷 159-173,210-211页

作者： Ma Changqian china university of geosciences, Wuhan, Hubei china university of geosciences Wuhan Hubei

The Zhoukoudian stock in Beijing is a concentric zoned complex intrusive body formed by two successive intrusions. Quartz-diorite formed by the first intrusion is scattered sparsely on the margins of the body, while granodiorite resulting from the second intrusion constitutes the main part of the intrusion. It exhibits three distinct petrographic zones macroscopically, and is chemically characterized by enrichment of high-temperature components, such as Mg, Ca, Sc, Ti, Cr, Mn. Fe and Co, on its border and merely slight enrichment of some low-temperature components, such as Na and Si, in its central part. A series of structural features indicate that the deformation of the intrusion and thermo-metamorphic rocks becomes weaker with an increase of distance from the contact, and that the intrusive body is a product of ballooning or inflating diapiric emplacement. Based on calculations of the density, viscosity and yield strength of magma and the reasonable diffusion constants and oxygen isotopic data, the mechanism of the compositional zonation of the major part of the stock is discussed. It is considered that the Soret effect, combined with double-diffusive convection, can explain the compositional zonation of the intrusion. Calculation of the ascent rates of magma shows that successive upwelling of magma got faster and faster with the progress of time.

关键词： The Magma-dynamic Mechaism of Emplacement and Compositional Zonation of the Zhoukoudian Stock Beijing

Distribution of recent Ostracoda from the coastal zone of Gaode and Weizhou Island, Zhuang Autonomous Region of Guangxi

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Acta Oceanologica Sinica 1990年第1期9卷 119-134页

作者： Ruan Peihua china university of geosciences, Chengfu Road, Beijing, china

-This paper deals with the recent ostracods and their distribution in littora! zones. The ostracods studied in this paper are all from the coastal zones of Gaode and Weizhou Island, Zhuang Autonomous Region of Guangxi. The present study shows that the richness and diversity of the ostracods from Gaode area are rather lower as compared with those from Weizhou Island, where individual numbers increase constantly from supralittoral to sublittoral zones. The ostracod associations of Weizhou Island are similar to those reported from the east coast of the Weizhou Island, and most of them are littoral and benthic forms of the order Podocopida and only a few of them are members of the order Myodocopoda (e. g. Ruti-derma, Cylindroleberis and Polycope). In this paper, the distributive character of the ostracods in the studied areas is analysed and discussed synthetically on the ground of their ecology, which will provide new information for the study of ecologic habitats, biogeographic provinciality and the Cenozoic biostratigraphy of ostracods.

关键词： view Zhuang Autonomous Region of Guangxi Distribution of recent Ostracoda from the coastal zone of Gaode and Weizhou Island

South china's Gondwana connection in the Paleozoic:Paleomagnetic evidence

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Progress in Natural Science:Materials International 2004年第1期14卷 86-91页

作者： ZHANG Shihong*(School of Earth Sciences and Resources, china university of geosciences, Beijing 100083, china) china Univ Geosci Sch Earth Sci & Resources Beijing 100083 Peoples R China

The reconstruction in which the South china Block (SCB) lies along the Great India Australia region of Gondwana margin is tested by using existing Paleozoic paleomagnetic data. Under the proposed reconstruction, all six high quality paleopoles from the SCB between the Early Cambrian and late Early Devonian (～400 Ma) are in good agreement with coeval paleopoles from Gondwana. Thereafter, the apparent polar wander paths for the SCB and Gondwana diverge markedly. This indicates that the SCB had been part of Gondwana and the connection was intact from at least Early Cambrian until late Early Devonian, but they began to separate by late Middle Devonian (～375 Ma).

关键词： South china block Gondwana paleomagnetism reconstruction

Discovery of potassic spilite (or poenite) in Langshan Group of Tanyaokou District,Inner Mongolia,china

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Chinese Science Bulletin 1999年第6期44卷 563-567页

作者： PENG RunminDepartment of Geology and Mineral Resources , china university of geosciences, Beijing 100083, china Department of Geology and Mineral Resources China University of Geosciences Beijing China

It is believed that the albite-potash-feldspar-greenschists in the middle Proterozoic Langshan Group in Tanyaokou District are synsedimentary potassic spilite （or poenite） based on the following facts and features: （ ⅰ ） they occur in beds and look blackish （or apple） green and compact; （ ⅱ ） they bear blasto-glomeroporphyritic and blastocrystalloclastic crystals which consist of （altered） albite laths with hollow skeleton crystal texture in which there are slender dark strips and minor pyroxene, and blasto-amygdaloid filled with pyrite, chlorite, magnetite, etc.; （ ⅲ ） the results of the petrochemical diagrams show that they are orthometamorphites; （ Ⅳ ） Sm-Nd isotopic age of them is 1 824 Ma (model age (tDM) is 2 006—2 132 Ma).

关键词： potassic spilite (or poenite) middle Proterozoic Tanyaokou Deposit Inner Mongolia.

Characteristics of Ore-Forming Fluids of Gold Deposits in Daqingshan District,Inner Mongolia,china

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International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 77-82页

作者： Jiuhua Xu YulingXie Dayi Qian Rufu Dine Jianping Li (Resource Engineering School, university of Science and Technology Beijha Beijing 100083, china) (china university of geosciences, Beijing 100083, china) Resource Engineering School University of Science and Technology Beijing Beijing 100083 China china university of geosciences Beijing 100083 China

***-weststrikingductileshearzonewithinagreelt,***:(1)pyrite-quartz,(2)quartz-Pyrite,(3)polymetallicsulfidesand(4)***-bearingveinsarenativegold,electrum,pyrite,chalcopyriteandgalena,buttheganguemineralsaremainlyquartz,secondarilysericite,***,silicification,***-formingfluidswerelowinsalinitieandhighinCO2content,MeasuredδDoffluidinclusionsinquartzfromtheoreveinsrangesfrom-65‰to-104‰,butδ18Oquartzfrom10.0‰to12.8‰.Thesedatashowthatthewaterinhydrothermalfluidprecipitatingtheorebodiescouldhavebeenmainlymagmaticwaterandmetamorphicwaterbutlocalmeteoricwatermighttakepartinthelatemineralization.δ13Cfromfl

关键词： fluid inclusions isotope composition gold deposit Daqingshan area

The Arcuate Nappe Structure on the Northern Margin of the Wuliang Moutnains in Western Yunnan

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Acta Geologica Sinica(English Edition) 1996年第2期70卷 123-133页

作者： Li Shujing and Shan Yehua china university of geosciences, Beijing china university of geosciences Beijing

The arcuate nappe structure on the north edge of the Wuliang Mountains in westernYunnan Province is a complex nappe structural system with multiple superimposed *** autochthonous system is a WNW-trending arcuate fold belt consisting of the Jurassic andCretaceous and the allochthonous system is mainly composed of Upper Triassic rocks. Generally,the nappe structure moved from south to north, with the hanging wall thrusting in a WNW direc-tion for a distance of over 10km. The deep nappe structural system was formed at depths ofabout 5-10km in an environment not exceeding the greenschist facies. It occurred in theOligocene (about 40-20 Ma).

关键词： arcuate nappe structure overthrust klippe multiple superimposed structure loading Wuliang Mountains in western Yunnan

Evolutionary patterns of Productida (Brachiopoda) morphology during the Permian in South china

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Science china Earth Sciences 2008年第11期51卷 1589-1600页

作者： ZHANG Yang1 & HE WeiHong1,2 1 Faculty of Earth Sciences, china university of geosciences, Wuhan 430074, china 2 Key Laboratory of Biogeology and Environmental Geology of Ministry of Education, china university of geosciences, Wuhan 430074, china Faculty of Earth Sciences China University of Geosciences Wuhan China Key Laboratory of Biogeology and Environmental Geology of Ministry of Education China University of Geosciences Wuhan China

The evolutionary patterns of Productida (brachiopod) morphology throughout the Permian show that while the percentage proportion of Productida (brachiopod) with strongly concentric and radial ornamentation declined from the Cisuralian to the Guadalupian, and then increased towards the Changhsingian via Wuchiapingian, the percentage proportion of Productida (brachiopod) with fine concentric and radial ornamentation distinctly increased from the Cisuralian to the Guadalupian, slightly declined towards the Wuchiapingian, and then increased towards the Changhsingian. From the Cisuralian to the Changhsingian, the percentage proportion of brachiopods with spinose ornamentation shows a persistent declining trend. The shell size generally indicates a miniaturization trend at species level during the Wuchiapingian to Changhsingian (including the transitional bed). These evolutionary patterns of brachiopod ornamentation and size are possibly related to the anoxia, food shortage, sea-level fluctuation, and change of substrate in the Permian (including the Permian-Triassic transitional interval) in South china.

关键词： brachiopod ornamentation size Permian South china

Exsolution of ilmenite and Cr-Ti magnetite from olivine of garnet-wehrlite

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Science china Earth Sciences 2005年第9期48卷 1368-1376页

作者： LIU Xiangwen1,2, JIN Zhenmin1,3, QU Jing2 & WANG Lu2 1. State Key Laboratory of Geological Processes and Mineral Resources, china university of geosciences, Wuhan 430074, china 2. Graduate School of china university of geosciences, Wuhan 430074, china 3. Faculty of Earth Sciences, china university of geosciences, Wuhan 430074, china State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan China Graduate School of china university of geosciences Wuhan China Faculty of Earth Sciences China University of Geosciences Wuhan China

Exsolution of rod-like ilmenite (Ilm) and Cr-Ti magnetite (Mt) have been found in olivine of garnet-wehrlite from the core of Chinese Continental Sciences Drilling (CCSD). Their composition, morphology, crystal structure and their topotaxies with host olivine have been studied in detail by the transmission electron microscopy (TEM) and electron probe microanaly- sis (EPMA) technique. It shows that rod-like Ilm exsolution reported in this paper has similar characteristic with that of Alpe Arami olivine, while Cr-Ti magnetite exsolution mentioned in this paper has large discrepancy with chromite exsolution in Alpe Arami olivine. These observations suggest that both of the exsolutions found in this paper should be solid solution phases in β-olivine at their first period, then experiencing decomposition of solid solution and therefore forming Ilm and Cr-Ti magnetite exsolution with the pressure decreasing. So, this garnet-wehrlite perhaps had been ever located in mantle transition zone with a minimum depth of 300 km.

关键词： garnet-wehrlite, ilmenite, magnetite, exsolution, CCSD.