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Multistage evolution of continental collision orogen:A case study for western Dabie orogen

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Chinese Science Bulletin 2009年第15期54卷 2568-2579页

作者： WU YuanBao State Key Laboratory of Geological Processes and Mineral Resources, faculty of earth {2.,{3. University of geosciences, wuhan 43.074,{3. State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi’an 710069,{3. State Key Laboratory of Geological Processes and Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China State Key Laboratory of Continental Dynamics Department of Geology Northwest University Xi’an 710069 China

The foramtion and evolution of collisional orogen is a prominent feature along convergent plate margins, and is generally a complex process. This article presents an integrated study of zircon genesis, U-Pb age and Lu-Hf isotope composition as well as geological characteristics for the western Dabie orogen to constrain its multi-stage evolution history. The results suggest that the formation of oceanic crust in the Huwan area was constrained at ca. 400―43. Ma, which was slightly later than the collision of the northern Qinling with the North china Block. It formed in a marginal basin in the northern margin of the Yangtze Block. The peak metamorphism of eclogite in the Huwan area occurred at ca. 3.0 Ma, and the timing of the initial exhumation of oceanic eclogite was about 2.0 Ma. The high to ultrahigh pressure (HP-UHP) metamorphic rocks in the Xinxian and the Hong'an metamorphic zones have the same ages and natures as those of the HP-UHP metamorphic rocks in the other Dabie-Sulu terrains, and also have experienced multi-stage exhumation, and thus can be taken as a coherent part of the Dabie-Sulu orogen. Therefore, the Qinling-Dabie-Sulu orogen is a typical multi-stage continental collision orogen, with an amalgamation process extending more than 2.0 Ma.

关键词：大别造山带大陆碰撞西部演变超高压变质岩碰撞造山带苏鲁造山带变质岩区

Characteristics of Albaillella (Albaillellarian,Radiolarian) Fauna from Guadalupian to Lopingian Series in Permian,South china

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Journal of china University of geosciences 2003年第4期14卷 314-320页

作者： Sun Dongying Xia Wenchen faculty of earth {2.,{3. University of geosciences, wuhan 43.074 faculty of earth {2. China University of Geosciences Wuhan 430074

On the basis of establishment of radiolarian biostratigraphy and conodont biostratigraphy, a radiolarian Albaillella fauna in the transitional environment from Guadalupian to Lopingian Series in Permian was found at a pelagic chert section in southeast Guangxi, South china. Radiolarian Albaillella is one of the most sensitive biology to the transitional environment. The Albaillella fauna shows an ecological evolutionary process from Guadalupian to Lopingian: declined stage-recovery stage-flourishing stage. The study of characteristics of the Albaillella fauna in the transitional environment may provide more information, not only for the subdivision and correlation of a high-resolution biostratigraphy, but also for influence of radiolarian Albaillella fauna on the pre-Lopingian mass extinction.

关键词： Permian Guadalupian-Lopingian Series transitional environment radiolarian Albaillella fauna.

Sequence of Ductile Shear Zones in UHP Metamorphic Province with in Dabie Massif,china

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Journal of earth Science 1998年第3期17卷 3-9页

作者： Suo Shutian Zhong Zengqiu faculty of earth {2.,{3. University of geosciences, wuhan 43.074

Structural studies in the Dabie massif show that distribution of strain is extremely heterogeneous and illustrates the pattern of deformation partitioning in the ultra high pressure (UHP) metamorphic province on all scales. Based on the field structural analysis along with microstructural observation, at least five widespread episodes of ductile shear zone systems are identified by using geometric, kinematic and rheological indicators and they constitute a shear zone sequence in the UHP metamorphic province within the Dabie massif (DM), china. Each shear zone system, for example, the UHP eclogite facies shear zone system in the sequence, exhibits its own features including geometric styles, mineral assemblages, metamorphic pt conditions and deformation regimes during the formation of such shear zone system. Detailed macro and micro scopical features of different episodes of the shear zones are given with respect to mechanism of strain localization and deformation partitioning. The tectonic significance during the creation and exhumation of the UHP metamorphic rocks is evaluated briefly, as well. It is argued that the ductile shear zones in the UHP metamorphic province play an important role in the Dabie mountain building geodynamic process.

关键词： ductile shear zone UHP metamorphic province exhumation deformation partitioning Dabie massif.

Mass and Energy Transportation in Ore-Forming Processes of Sulfide Deposits in Tongling District

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Journal of earth Science 1999年第4期18卷 299-304页

作者： Cen Kuang Yu Chongwen(faculty of earth {2.,{3. University of geosciences, wuhan 43.074) faculty of earth {2. China University of GeosciencesWuhan 430074

Based on dynamics of heat conduction, fluid flow caused by heating and chemical material transport induced by fluid flow, temperature and stream fields of fluid flow in ore-forming processes of Cu-Au sulfide in the Tongling district deposits was modeled and analyzed. It is shown that: (1) Mass and energy flow caused by fluid flow is key problem of kythrothermal ore-forming processes; the heating from magma intruded is basic power for driving fluid flow. (2. occurrence of pluton, different chemical property and porosity of wall rocks and infiltration restrict the specifically field of precipitation for ore-forming ***, the dissolution and precipitation field for ore-forming material in deposit can be forecasted. (3. Iron and sulfur material comes mostly from sandstone formation of Wutong Group, which contains pyrite and high porosity. The cataclastic dolomite interlayered in sandstone and limestone is a favorable place for ore accumulating. The difference of chemical property between sandstone and dolomite forms a favorable interface for ore-forming processes.

关键词： heat conduction mass transportation fluid path-line streamline

Mesozoic radiolarian chert from the middle sector of the Yarlung Zangbo suture zone,Tibet and its tectonic implications

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Science china earth {2. 2006年第4期49卷 348-357页

作者： ZHU Jie1,2. DU Yuansheng1, LIU Zaoxue2. FENG Qinglai1, TIAN Wangxue2. LI Jinping2.& WANG Changping2.1. faculty of earth {2.,china University of Geology, wuhan 43.074, china 2. Hubei Institute of Regional Geology Survey, wuhan 43.03., china 1. faculty of earth {2. China University of Geology Wuhan 430074 China 2. Hubei Institute of Regional Geology Survey Wuhan 430034 China

Three radiolarian fauna, aged as the Middle-Late Triassic, Late Jurassic-Early Creta- ceous and Cretaceous radiolarian fauna, have been recognised in the radiolarian cherts from the middle sector of the Yarlung Zangbo suture zone, southern Tibet, china. The average contents of SiO2.in the radiolarian cherts of the Middle-Late Triassic and Late Jurassic-Early Cretaceous are 90.2.% and 92.58% respectively, with average ratios of Al/(Al+Fe+Mn) as 0.75 and 0.74 respectively, the average ratios of MnO/TiO2.as 0.3. and 1.2., the average ratios of Ce/Ce* as 1.15 and 1.03. and the average ratios of LaN/CeN as 0.85 and 0.93. These geochemical features indicate that both of them are biogenic, deposited in a continental margin basin. The SiO2.content of the Early Cretaceous radiolarian chert is 94.12., with the ratio of Al/(Al+Fe+Mn) as 0.59, ratio of MnO/TiO2.as 4.3., ratio of Ce/Ce* as 0.60, ratio of LaN/CeN as 1.59, which imply that the chert is biogenic and was deposited in a pelagic basin. The Middle-Late Triassic association of the radiolarian chert and turbidites as well as their geochemical characteristics indicates the existence of a strong rifting marginal basin in the belt of the Yarlung Zangbo River then. The association of radiolarian chert and bedded basalt indicate an initial Tethyan ocean basin in southern Tibet during the Late Jurassic-Early Cretaceous. The early Cretaceous radiolarian chert coexisting with pillow basalt in top of the ophiolite suite represents sediments from the oceanic Tethyan basin.

关键词： radiolarian chert, sedimentary geochemistry, Mesozoic, Yarlung Zangbo suture zone, Tibet.

Multi-Layered Low-Angle Ductile Detachment System in Dabie-Sulu UHPM and HPM Belts, china

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Journal of earth Science 1999年第3期18卷 187-193页

作者： Suo Shutian Zhong Zengqiu(faculty of earth {2.,{3. University of geosciences, wuhan 43.074) faculty of earth {2. China University of Geosciences Wuhan 430074

The present-day observed crustal-scale tectonic style of ultrahigh-pressure metamorphic (UH-PM) and high-pressure metamorphic (HPM ) belts in the Dabie-Sulu region was dominantly formedby extensional processes, postdating the Triassic collision between the Sino-Korean and Yangtze cratons. The extensional structures overprinting the previous structures related to contraction that produced the thickened continental crust of the UHPM and HPM belts, in particular display the typical features of a Cordilleran-type metamorphic core complex, in which at least four regionalscale, low-angle ductile shear zones that constitute a detachment system, are recognized in the Dabie region. In the Sulu region, the extensionaI structures show in the form of small-scale domes or a regional-scale SE-dipping pseudo-monocline. The geometry and the kinematics of tbe detachment zones are briefly described and their significance for the exhumation of UHPM and HPM rocks is discussed. It is iniliated that the subhorizontal crustal-scale extensional flow in the middle-lower crust, under amphibolite- to greenschist-facies conditions, was an important tectonothermal process at 2.0- 170 Ma and the exhumation or the UHPM and HPM rocks was achieved at least in part along multi-layered detachment zones. The regional detachment system has been the main factor enabling UHPM and HPM rocks to be brought from middle-lower crustal levels to middle-upper crustal levels.

关键词： detachment system UHPM and HPM rocks exhumation ductile shear zone,Dabie massif Dabie-Sulu region

New stylophorans(Echinodermata) from the Upper Cambrian of Guangxi,South china

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Science china earth {2. 2008年第2期51卷 181-186页

作者： HAN NaiRen1 & CHEN GuiYing1,2.1 Department of Resources and Environmental Engineering, Guilin University of Technology, Gulin 541004, china 2.{3. of {2. sciences, china University of Geoscience, wuhan 43.074, china Department of Resources and Environmental Engineering Guilin University of Technology Gulin 541004 China faculty of earth {2. China University of Geoscience Wuhan 430074 China

This paper describes for the first time the cornute stylophorans (Echinodermata) in china. The new material came from the Guole Formation of the Furongian (Late Cambrian) in the Guole area of Jingxi, Guangxi Province, South china. These new cornute specimens are preserved in situ and found along with well-preserved trilobites and brachiopods. One new species, Phyllocystis jingxiensis sp. nov., is proposed to accommodate these unusual materials. The new species is defined by the small, heart-shaped theca with the frame composed of ten narrow, smooth and thick marginal plates, three adoral plates and distinctive zygal and aulacophore. Both supracentrals and infracentrals are polygonal-outlined. The marginal plate M1' on the inferior face extends posteriorly to form zygal that possesses a broadened proximal end and the proximal portion joining with the conjunction between M4 and M5 on the inferior face. Aulacophore comprises ten segments at its proximal part and is conical at the middle part (named stylocone). Its distal portion is rather long and bears conspicuous ambulacrum grooves. Tectals are horizontally arranged on superior face and obliquely arranged on inferior face. Both cothurnopore and anal pyramid are vaguely seen on the right anterior corner and the extremity of theca's superior face.

关键词： Phyllocystis Stylophora Echinodermata Cambrian Guangxi South china

Depositional Model and Tectonic Evolution of Tertiary Transform-Extensional Basins in Northeast china: Case Study on Yitong and Damintun Grabens

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Journal of earth Science 1997年第1期16卷 62-67页

作者：  Xie Xinong Huang Yanqiu faculty of earth Resources,{2. University of {3., wuhan 43.074Lu Zongshengfaculty of earth sciences,{2. University of {3., wuhan 43.074

? The formation and evolution of the Tertiary transformextensional basins in Northeast china are controlled by extensional and strikeslidding combinational processes because the giant strikeslip fault system, TanchengLujiang fault, cut through the basement or margin. Two kinds of structural styles have been identified in Northeast china: Yitong and Damintun styles. The former shows a clear asymmetry, in which sediments came mainly from two lateral sides and thick filling sediments were adjacent to the main strikeslip fault. The latter shows symmetry filling, in which sediments came from the long axial ends in addition to from two lateral sides. The tectonic evolution of Tertiary transformextensional basins in Northeast china underwent three stages: Eocene extensional, Oligocene transformextensional and Neogene transpressional stages.

关键词： transformextensional basin Tertiary Yitong graben Xialiaohe basin.

Differentiation of Natural and Irradiated Blue Topaz by Cathodoluminescence(CL) Properties

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地学前缘 2009年第S1期16卷 169-170页

作者： Ying Song~(1,2.,Xinqiang Yuan~2.1.faculty of {3. Resources,{2. University of geosciences(wuhan),wuhan 43.074,{2.. 2.Gemmological Institute,{2. University of geosciences(wuhan),wuhan 43.074,{2.

Blue colored topaz is one of the most recognized gemstones ***,it is rarely found in the field and the products have been made mostly in laboratory using gamma,neutron and electron irradiation or combinations of these *** of the blue color in topaz remains not well understood, largely due to a lack of nondestructive way in idnetifying the blue *** we report a compari-

关键词： cathodoluminescence natural blue topaz irradiated blue topaz