DOCSLIB.ORG

Appalachian-Style Multi-Terrane Wilson Cycle Model for the Assembly of South China

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Appalachian-Style Multi-Terrane Wilson Cycle Model for the Assembly of South China Appalachian-style multi-terrane Wilson cycle model for the assembly of South China Shoufa Lin1,2*, Guangfu Xing3, Donald W. Davis4, Changqing Yin5, Meiling Wu1, Longming Li2, Yang Jiang3, and Zhihong Chen3 1Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada 2School of Resources and Environment, Hefei University of Technology, Hefei 230026, China 3China Geological Survey (Nanjing Center), Nanjing 210016, China 4Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada 5School of Earth Sciences and Engineering, Sun Yat-Sen University, Guangzhou 510275, China ABSTRACT northeastern Jiangnan belt consists of two ter- The evolution of South China involved accretion-collision of multiple terranes from the ranes (sensu lato), Jiuling and Huaiyu, separated Proterozoic to the Mesozoic. Zircon U-Pb ages, Hf data, and structural data indicate that by the Northeast Jiangxi fault (Fig. 1). the Cathaysia block consists of two terranes, West Cathaysia and East Cathaysia, separated by a newly recognized major strike-slip fault. We propose that West Cathaysia was part of a Jiuling Terrane microcontinent that originated from a Grenvillian-aged orogen in the Rodinia supercontinent, The Jiuling terrane is characterized by a thick East Cathaysia originated from an Indosinian-aged orogen in the Paleo-Tethyan regime to sequence of middle Neoproterozoic (ca. 850– the south and was translated to the east of West Cathaysia through strike-slip motion, and 825 Ma) turbidites and minor volcanic rocks the early Paleozoic Wuyi-Yunkai orogeny was a result of direct collision of West Cathaysia (e.g., the Xikou Group) and includes the ca. 833 with a yet-unidentified terrane that rifted away after the collision. We conclude that a multi- Ma Fuchuan ophiolite (e.g., Yin et al., 2013). terrane Wilson cycle (multi-terrane accretion-collision, large-scale strike-slip motion, and These rocks are generally interpreted to have separation of two terranes by post-collisional rifting along the suture zone) characterizes the formed in an arc−back-arc system. history of South China and may be a common feature of orogens. Huaiyu Terrane INTRODUCTION progressive closing and reopening of oceans, The Huaiyu terrane is characterized by a Wilson (1966) proposed a basic model for that became known as the Wilson cycle. This series of late Mesoproterozoic to early Neopro- the tectonic history of eastern North America model has since been refined using detailed evi- terozoic supracrustal rocks that are distinctly (Grenville and Appalachian orogens), involving dence for multi-terrane accretion-collision and older than those in the Jiuling terrane (Fig. 2). strike-slip faulting (e.g., van Staal et al., 2009; Major units include (1) the Tieshajie Formation 0 Lin et al., 2013). (Fig. 3), a ca. 1160 Ma continental rift sequence 110 E North China Craton SShuangxiwuhuangxiwu G. ShuangxiwuShuangxiwSShanghaihuanghai South China is interpreted to have formed (Li et al., 2013); (2) the Tianli schist (Fig. 3), a Kongling Qinling-Dabie F Complex Shangh261ai by the amalgamation of two blocks, Yangtze Mesoproterozoic metasedimentary succession NEJ u g y and Cathaysia (Fig. 1), but the proposed timing that was deformed and metamorphosed at ca. n i li a Yangtze Xikou G. u iu CChencahencai of amalgamation varies wildly, corresponding 1.0 Ga (Li et al., 2007); and (3) the Shuangxiwu JJiulin HHuaiyu 300 N CComplexomplex to various known tectono-thermal events, from Group (Fig. 1), a ca. 970–890 Ma juvenile arc lt WWuuyyishanishan 1832 be JSF n Paleoproterozoic (Dong et al., 2015) to early Neo- sequence that was deformed and metamorphosed na F ia g ia F s Fig. 3 n s y proterozoic (ca. 1.0–0.9 Ga, Grenvillian age; e.g., before ca. 850 Ma (Li et al., 2009). The terrane ia t y W a JJiangnan belt s a NNWFF h e h t t a Li et al., 2007) to middle Neoproterozoic (ca. 820 also contains ophiolite slivers, including the ca. WWesta CCathaysia t C s Ma, Jinning or Sibao age; e.g., Zhao et al., 2011; 970 Ma Zhangshudun (Xiwan) ophiolite (Fig. 3) a EEast Cathaysia Yin et al., 2013) to early Paleozoic (ca. 460–420 that was obducted at ca. 880 Ma (Li et al., 2008). CCathaysiathaysia 200 km Yunkai 0 Ma; Caledonian age) to Mesozoic (ca. 250–230 The Huaiyu terrane has been interpreted as 120 E HHongong Ma; Indosinian age). In this paper, we propose an part of a composite terrane that formed by the KKongong alternative interpretation that is closer to the Wil- amalgamation of multiple terranes at ca. 1.0– Yangtze Precambrian n South son cycle. That is, South China formed by accre- 0.88 Ga (Yin et al., 2013). basement Jiangna 0 China athaysia tion-collision of multiple terranes, where each of 20 N Greater West C Cathaysia the above tectono-thermal events corresponds to Timing of Amalgamation of the Jiuling and 1100 E an accretional-collisional event and was modified Huaiyu Terranes Figure 1. Tectonic framework of eastern by later rifting and large-scale strike-slip motion. The pre–820 Ma units in both terranes are South China (modified from Cawood et al., metamorphosed to greenschist facies and uncon- 2013). NEJF—Northeast Jiangxi fault; JSF— YANGTZE BLOCK AND JIANGNAN BELT formably overlain by middle Neoproterozoic Jiangshan-Shaoxing fault; NWFF—Northwest The Yangtze block contains an Archean– (815–750 Ma) (e.g., the Banxi Group) to middle Fujian fault; G.—Group. Black numbers 261 and 1832 are U-Pb zircon ages (in Ma) (meta- Paleoproterozoic crystalline basement. Along Silurian cover (Fig. 2). This unconformity cor- morphic and magmatic, respectively; see Data its southeastern margin is a Neoproterozoic fold responds to the Jinning or Sibao orogeny, which Repository [see footnote 1] for sources). belt called the Jiangnan belt (or orogen) that was related to the amalgamation of the two ter- is generally considered as the collision zone ranes and the closure of the Jiuling back-arc *E-mail: [email protected] between the Yangtze and Cathaysia blocks. The basin (e.g., Yin et al., 2013). GEOLOGY, April 2018; v. 46; no. 4; p. 319–322 | GSA Data Repository item 2018090 | https://doi.org/10.1130/G39806.1 | Published online 9 February 2018 ©GEOLOGY 2018 The Authors.| Volume Gold 46 |Open Number Access: 4 | www.gsapubs.orgThis paper is published under the terms of the CC-BY license. 319 Downloaded from http://pubs.geoscienceworld.org/gsa/geology/article-pdf/46/4/319/4102178/319.pdf by guest on 24 September 2021 Neoproterozoic ages. They are intruded by early Greater West Cathaysia terrane East (A) West Cathaysia Jiuling West Cathaysia terrane Paleozoic mostly felsic intrusions. Age Huaiyu terrane Cathaysia terrane terrane Ten new samples were collected from West Ga Devonian and younger (D–) D– Cathaysia for zircon sensitive high-resolution 0.40 ca. 815 Ma to middle Silurian ?–O3 ion microprobe (SHRIMP) U-Pb geochronology 0.80 Banxi Group ? Igneous ? and Hf isotope analysis. The results are sum- zircon Fuchuan 0.84 ophiolite marized below and in Figures 3 and 4. More Xikou details are given in the GSA Data Repository1. Metamorphic 0.88 Group & t zircon equivalents A pegmatite dike, a biotite gabbro, a two- Number 0.92 Zhangshudun mica granite, and a quartz diorite (samples C, E, ophiolite Age (Ga) 0.96 F, and H, respectively) yield magmatic ages of Shuangxiwu 441 ± 3 Ma, 446 ± 4 Ma, 440 ± 2 Ma, and 447 1.00 Group (B) East Cathaysia Jiangshan-Shaoxing fault ± 4 Ma, respectively. These magmatic ages are 1.20 Tianli Tieshajie Northwest Fujian faul schist Formation coeval with metamorphic ages of 440 ± 4 Ma, 446 ± 6 Ma, 450 ± 10 Ma, and 443 ± 7 Ma from 1.50 Metamorphic two biotite gneisses, a felsic metavolcanic rock, zircon 2.00 Northeast Jiangxi fault and an amphibolite (samples A, D, G and M, Igneous Age? zircon 2.50 respectively). A porphyritic granite (sample L) 0 40 0 40 Number 0 10 0 80 0 80 yields a younger age of 404 ± 2 Ma. Gneissic 1.00 melanosome and a felsic metavolcanic rock 2.00 (samples B and G) yield magmatic ages of 907 Number Age (Ga) 3.00 ± 10 Ma and 911 ± 7 Ma, respectively, with evidence for a slightly younger metamorphic 4.00 Hf model age histograms event present in some samples (e.g., sample B; Figure 4. Compilation of new (colored) and Unconformity Magmatism Deformation/ metamorphism see the Data Repository). previous results of Lu-Hf analyses for zircons Mostly sedi- Volcano- from West Cathaysia (A) and East Cathaysia sedimentary rocks Ophiolite mentary rocks The new data, supplemented by previous (B), South China. Insets are histograms of Figure 2. Summary of main characteristics of results, indicate the following characteristics two-stage Hf model ages of magmatic zir- cons. CHUR—chondritic uniform reservoir; terranes of study area, South China. ?–O3— for West Cathaysia: (1) the Precambrian base- late Ordovician and older, base undefined. See ment rocks were affected by a major magmatic DM—depleted mantle. See Data Repository (see footnote 1) for more information. Data Repository (see footnote 1) for sources and metamorphic event in the early Paleozoic for Hf data. (ca. 460–420 Ma), called the Wuyi-Yunkai or “Caledonian” orogeny (Li et al., 2010; Wang et paths. Peak metamorphism reached upper al., 2013); (2) their protoliths mostly have ages amphibolite to granulite/eclogite facies (>1 GPa CATHAYSIA BLOCK between ca. 1.00 and ca. 0.91 Ga (Figs. 3 and in metapelite; e.g., Zhao and Cawood, 1999), The Cathaysia block is divided into two ter- 4; see also Wang et al., 2014); and (3) two-stage with associated partial melting. ranes, East Cathaysia and West Cathaysia, with zircon Hf model ages (TMD2) cluster between 1.5 contrasting geological histories (Figs.
Load more

Recommended publications
  • Two Contrasting Phanerozoic Orogenic Systems Revealed by Hafnium Isotope Data William J
    ARTICLES PUBLISHED ONLINE: 17 APRIL 2011 | DOI: 10.1038/NGEO1127 Two contrasting Phanerozoic orogenic systems revealed by hafnium isotope data William J. Collins1*(, Elena A. Belousova2, Anthony I. S. Kemp1 and J. Brendan Murphy3 Two fundamentally different orogenic systems have existed on Earth throughout the Phanerozoic. Circum-Pacific accretionary orogens are the external orogenic system formed around the Pacific rim, where oceanic lithosphere semicontinuously subducts beneath continental lithosphere. In contrast, the internal orogenic system is found in Europe and Asia as the collage of collisional mountain belts, formed during the collision between continental crustal fragments. External orogenic systems form at the boundary of large underlying mantle convection cells, whereas internal orogens form within one supercell. Here we present a compilation of hafnium isotope data from zircon minerals collected from orogens worldwide. We find that the range of hafnium isotope signatures for the external orogenic system narrows and trends towards more radiogenic compositions since 550 Myr ago. By contrast, the range of signatures from the internal orogenic system broadens since 550 Myr ago. We suggest that for the external system, the lower crust and lithospheric mantle beneath the overriding continent is removed during subduction and replaced by newly formed crust, which generates the radiogenic hafnium signature when remelted. For the internal orogenic system, the lower crust and lithospheric mantle is instead eventually replaced by more continental lithosphere from a collided continental fragment. Our suggested model provides a simple basis for unravelling the global geodynamic evolution of the ancient Earth. resent-day orogens of contrasting character can be reduced to which probably began by the Early Ordovician12, and the Early two types on Earth, dominantly accretionary or dominantly Paleozoic accretionary orogens in the easternmost Altaids of Pcollisional, because only the latter are associated with Wilson Asia13.
    [Show full text]
  • Assembly, Configuration, and Break-Up History of Rodinia
    Author's personal copy Available online at www.sciencedirect.com Precambrian Research 160 (2008) 179–210 Assembly, configuration, and break-up history of Rodinia: A synthesis Z.X. Li a,g,∗, S.V. Bogdanova b, A.S. Collins c, A. Davidson d, B. De Waele a, R.E. Ernst e,f, I.C.W. Fitzsimons g, R.A. Fuck h, D.P. Gladkochub i, J. Jacobs j, K.E. Karlstrom k, S. Lu l, L.M. Natapov m, V. Pease n, S.A. Pisarevsky a, K. Thrane o, V. Vernikovsky p a Tectonics Special Research Centre, School of Earth and Geographical Sciences, The University of Western Australia, Crawley, WA 6009, Australia b Department of Geology, Lund University, Solvegatan 12, 223 62 Lund, Sweden c Continental Evolution Research Group, School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia d Geological Survey of Canada (retired), 601 Booth Street, Ottawa, Canada K1A 0E8 e Ernst Geosciences, 43 Margrave Avenue, Ottawa, Canada K1T 3Y2 f Department of Earth Sciences, Carleton U., Ottawa, Canada K1S 5B6 g Tectonics Special Research Centre, Department of Applied Geology, Curtin University of Technology, GPO Box U1987, Perth, WA 6845, Australia h Universidade de Bras´ılia, 70910-000 Bras´ılia, Brazil i Institute of the Earth’s Crust SB RAS, Lermontova Street, 128, 664033 Irkutsk, Russia j Department of Earth Science, University of Bergen, Allegaten 41, N-5007 Bergen, Norway k Department of Earth and Planetary Sciences, Northrop Hall University of New Mexico, Albuquerque, NM 87131, USA l Tianjin Institute of Geology and Mineral Resources, CGS, No.
    [Show full text]
  • New Constraints on Intraplate Orogeny in the South China Continent
    Gondwana Research 24 (2013) 902–917 Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr Systematic variations in seismic velocity and reflection in the crust of Cathaysia: New constraints on intraplate orogeny in the South China continent Zhongjie Zhang a,⁎, Tao Xu a, Bing Zhao a, José Badal b a State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China b Physics of the Earth, Sciences B, University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain article info abstract Article history: The South China continent has a Mesozoic intraplate orogeny in its interior and an oceanward younging in Received 16 December 2011 postorogenic magmatic activity. In order to determine the constraints afforded by deep structure on the for- Received in revised form 15 May 2012 mation of these characteristics, we reevaluate the distribution of crustal velocities and wide-angle seismic re- Accepted 18 May 2012 flections in a 400 km-long wide-angle seismic profile between Lianxian, near Hunan Province, and Gangkou Available online 18 June 2012 Island, near Guangzhou City, South China. The results demonstrate that to the east of the Chenzhou-Linwu Fault (CLF) (the southern segment of the Jiangshan–Shaoxing Fault), the thickness and average P-wave veloc- Keywords: Wide-angle seismic data ity both of the sedimentary layer and the crystalline basement display abrupt lateral variations, in contrast to Crustal velocity layering to the west of the fault. This suggests that the deformation is well developed in the whole of the crust Frequency filtering beneath the Cathaysia block, in agreement with seismic evidence on the eastwards migration of the orogeny Migration and stacking and the development of a vast magmatic province.
    [Show full text]
  • Deconvolving the Pre-Himalayan Indian Margin E Tales of Crustal Growth and Destruction
    Geoscience Frontiers 10 (2019) 863e872 HOSTED BY Contents lists available at ScienceDirect China University of Geosciences (Beijing) Geoscience Frontiers journal homepage: www.elsevier.com/locate/gsf Research Paper Deconvolving the pre-Himalayan Indian margin e Tales of crustal growth and destruction Christopher J. Spencer a,b,*, Brendan Dyck c, Catherine M. Mottram d,e, Nick M.W. Roberts b, Wei-Hua Yao a,f, Erin L. Martin a a Earth Dynamics Research Group, The Institute for Geoscience Research (TIGeR), Department of Applied Geology, Curtin University, 6845, Perth, Australia b NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK c Department of Earth Sciences, Simon Fraser University, University Drive, Burnaby V5A 1S6, Canada d Department of Environment, Earth and Ecosystems, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK e School of Earth and Environmental Sciences, University of Portsmouth, Portsmouth, PO1 3QL, UK f Schoolof Earth Sciences and Engineering, SunYat-sen University, Guangzhou 510275, China article info abstract Article history: The metamorphic core of the Himalaya is composed of Indian cratonic rocks with two distinct crustal Received 30 November 2017 affinities that are defined by radiogenic isotopic geochemistry and detrital zircon age spectra. One is Received in revised form derived predominantly from the Paleoproterozoic and Archean rocks of the Indian cratonic interior and is 4 February 2018 either represented as metamorphosed sedimentary rocks of the Lesser Himalayan Sequence (LHS) or as Accepted 22 February 2018 slices of the distal cratonic margin. The other is the Greater Himalayan Sequence (GHS) whose prove- Available online 16 March 2018 nance is less clear and has an enigmatic affinity.
    [Show full text]
  • Locating South China in Rodinia and Gondwana: a Fragment of Greater India Lithosphere?
    Locating South China in Rodinia and Gondwana: A fragment of greater India lithosphere? Peter A. Cawood1, 2, Yuejun Wang3, Yajun Xu4, and Guochun Zhao5 1Department of Earth Sciences, University of St Andrews, North Street, St Andrews KY16 9AL, UK 2Centre for Exploration Targeting, School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia 3State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China 4State Key Laboratory of Biogeology and Environmental Geology, Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China 5Department of Earth Sciences, University of Hong Kong, Pokfulam Road, Hong Kong, China ABSTRACT metamorphosed Neoproterozoic strata and From the formation of Rodinia at the end of the Mesoproterozoic to the commencement unmetamorphosed Sinian cover (Fig. 1; Zhao of Pangea breakup at the end of the Paleozoic, the South China craton fi rst formed and then and Cawood, 2012). The Cathaysia block is com- occupied a position adjacent to Western Australia and northern India. Early Neoproterozoic posed predominantly of Neoproterozoic meta- suprasubduction zone magmatic arc-backarc assemblages in the craton range in age from ca. morphic rocks, with minor Paleoproterozoic and 1000 Ma to 820 Ma and display a sequential northwest decrease in age. These relations sug- Mesoproterozoic lithologies. Archean basement gest formation and closure of arc systems through southeast-directed subduction, resulting is poorly exposed and largely inferred from the in progressive northwestward accretion onto the periphery of an already assembled Rodinia. presence of minor inherited and/or xenocrys- Siliciclastic units within an early Paleozoic succession that transgresses across the craton were tic zircons in younger rocks (Fig.
    [Show full text]
  • Wilson Cycle Guide
    Wilson Cycle Description Lynn S. Fichter and Eric Pyle Department of Geology and Environmental Science James Madison University Layout of this Guide For each stage represented in this Wilson Cycle, several pieces of information are provided: Description of Process: a description of the forces acting on a particular location, and the results of those forces; Composition: the particular rock types that result from these forces, including chemical make up, major minerals present, and texture (grain size and orientation), expressed in photographs, verbal descriptions, and categorical graphs; Specific Locations, Present and Past: the map locations of examples of the environment, with current and past locations represented. Stage A: Stable Continental Craton Description of Process: This stage represents the basis of all existing continents, showing in a simplified fashion both continental crust and adjacent oceanic crust, both of which lie over the mantle. You will notice that the continental crust is considerably thicker than the ocean crust. Continental crust is less dense than oceanic crust (approximately 2.7 g/cm3 vs. 3.3 g/cm3), and so “rides” higher over the mantle. Continental crust is also more rigid that oceanic crust. Furthermore, the development of continental crust involves considerable thickening. Composition: This diagram represents considerable simplification, in that the internal structure has not been shown, but is represented as a crystalline “basement” for the continent. This basement material represents a variety of rock types, including granites and diorites, gneisses and schists, and various sedimentary rocks. Taken as a whole, the average composition of the basement rock is the same as a granodiorite – enriched in sodium, potassium and silica-rich minerals, such as alkali feldspar, sodium plagioclase, and quartz, and depleted in iron/magnesium, silica poor minerals, such as olivine, pyroxene, and amphibole.
    [Show full text]
  • Destruction of the North China Craton
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/257684968 Destruction of the North China Craton Article in Science China Earth Science · October 2012 Impact Factor: 1.49 · DOI: 10.1007/s11430-012-4516-y CITATIONS READS 69 65 6 authors, including: Rixiang Zhu Yi-Gang Xu Chinese Academy of Sciences Chinese Academy of Sciences 264 PUBLICATIONS 8,148 CITATIONS 209 PUBLICATIONS 7,351 CITATIONS SEE PROFILE SEE PROFILE Tianyu Zheng Chinese Academy of Sciences 62 PUBLICATIONS 1,589 CITATIONS SEE PROFILE All in-text references underlined in blue are linked to publications on ResearchGate, Available from: Yi-Gang Xu letting you access and read them immediately. Retrieved on: 26 May 2016 SCIENCE CHINA Earth Sciences Progress of Projects Supported by NSFC October 2012 Vol.55 No.10: 1565–1587 • REVIEW • doi: 10.1007/s11430-012-4516-y Destruction of the North China Craton ZHU RiXiang1*, XU YiGang2, ZHU Guang3, ZHANG HongFu1, XIA QunKe4 & ZHENG TianYu1 1 State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; 2 State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; 3 School of Resource and Environmental Engineering, Hefei University of Technology, Hefei 230009, China; 4 School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China Received March 27, 2012; accepted June 18, 2012 A National Science Foundation of China (NSFC) major research project, Destruction of the North China Craton (NCC), has been carried out in the past few years by Chinese scientists through an in-depth and systematic observations, experiments and theoretical analyses, with an emphasis on the spatio-temporal distribution of the NCC destruction, the structure of deep earth and shallow geological records of the craton evolution, the mechanism and dynamics of the craton destruction.
    [Show full text]
  • Cathaysia, Gondwanaland, and the Paleotethys in the Evolution of Continental Southeast Asia
    GEOSEA V Proceedings Vol. !!, Ceo!. Soc. Malaysia, Bullelin20, August 1986; pp. 179-199 Cathaysia, Gondwanaland, and the Paleotethys in the evolution of continental Southeast Asia YURI G. GATINSKY1 AND CHARLES S. HUTCHISO 2 1All-Union Institute of Geology of Foreign Countries, Dimitrova, 7 Moscow, 109180, U.S.S.R. 2Department of Geology, University of Malaya, 59100 Kuala Lumpur, Malaysia . Abstract: Continental Southeast A ia is dominated by Precambrian continenral blocks overlain by Late Proterozoic to Paleozoic platform successions, representing Atlantic-type rifted miogeocl inal margins. All the blocks appear to have rifted and drifted from the Australian part of Gondwanaland. The timing and extent of their eparati on is analysed by the distribution of Penni an Cathaysian Gigamop­ leris and Gondwana Glossop1eris floras, assisted by dated tectono-structural units, paleoclimate indicators, and good quality paleomagnetic data. Between the blocks lie narrow intensely folded Phanerozoic mobile belts, which developed on the oceanic crust of the Paleotethys ocean, characterized by pelagic-turbidite flysch equences which shallowed as the oceans narrowed. The narrowing was effected by subduction resulting in island arcs within the oceans, and cordilleran volcano-plutonic arcs along the block margin . Extinction of the bas ins resulted in collision zones containing S-type granites and utu re zones containing dismembered ophi olites. Post-consolidation pl ate readju tments resulted in wrench and rift fa ulting in several places while convergence conti nued elsewhere. The tectonic analysis has been carried out by recognizing tectonic elements (structural-formati onal unit ~) for selected Phanerozoic time frame . We also pre ent a Phanerozoic sequence of palinspatic reconstructiors for the ri fti ng and drifting of the blocks from northern Australia.
    [Show full text]
  • Connecting the Deep Earth and the Atmosphere
    In Mantle Convection and Surface Expression (Cottaar, S. et al., eds.) AGU Monograph 2020 (in press) Connecting the Deep Earth and the Atmosphere Trond H. Torsvik1,2, Henrik H. Svensen1, Bernhard Steinberger3,1, Dana L. Royer4, Dougal A. Jerram1,5,6, Morgan T. Jones1 & Mathew Domeier1 1Centre for Earth Evolution and Dynamics (CEED), University of Oslo, 0315 Oslo, Norway; 2School of Geosciences, University of Witwatersrand, Johannesburg 2050, South Africa; 3Helmholtz Centre Potsdam, GFZ, Telegrafenberg, 14473 Potsdam, Germany; 4Department of Earth and Environmental Sciences, Wesleyan University, Middletown, Connecticut 06459, USA; 5DougalEARTH Ltd.1, Solihull, UK; 6Visiting Fellow, Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland, Australia. Abstract Most hotspots, kimberlites, and large igneous provinces (LIPs) are sourced by plumes that rise from the margins of two large low shear-wave velocity provinces in the lowermost mantle. These thermochemical provinces have likely been quasi-stable for hundreds of millions, perhaps billions of years, and plume heads rise through the mantle in about 30 Myr or less. LIPs provide a direct link between the deep Earth and the atmosphere but environmental consequences depend on both their volumes and the composition of the crustal rocks they are emplaced through. LIP activity can alter the plate tectonic setting by creating and modifying plate boundaries and hence changing the paleogeography and its long-term forcing on climate. Extensive blankets of LIP-lava on the Earth’s surface can also enhance silicate weathering and potentially lead to CO2 drawdown (cooling), but we find no clear relationship between LIPs and post-emplacement variation in atmospheric CO2 proxies on very long (>10 Myrs) time- scales.
    [Show full text]
  • Proterozoic First-Order Sedimentary Sequences of the Sao Francisco
    Marine and Petroleum Geology 33 (2012) 127e139 Contents lists available at SciVerse ScienceDirect Marine and Petroleum Geology journal homepage: www.elsevier.com/locate/marpetgeo Proterozoic first-order sedimentary sequences of the São Francisco craton, eastern Brazil Fernando F. Alkmima,*, Marcelo A. Martins-Netob a Departamento de Geologia, Escola de Minas, Universidade Federal de Ouro Preto, Morro do Cruzeiro, 35.400.000 Ouro Preto, MG, Brazil b Vicenza Mineração, Av. Agulhas Negras, 580, Mangabeiras, 30210-340 Belo Horizonte, MG, Brazil article info abstract Article history: The São Francisco craton in eastern Brazil hosts sedimentary sequences deposited between the Paleo- Received 4 May 2010 archean (w3300 Ma) and Late Neoproterozoic (w580 Ma). Proterozoic successions occurring in this Received in revised form region comprise five 1st-order sedimentary sequences, which besides episodes of global significance 15 August 2011 record major basin-forming events. The ca. 8000 m-thick Minas-Itacolomi 1st-order sequence, exposed Accepted 18 August 2011 in the Brazilian mining district of the Quadrilátero Ferrífero and containing as marker bed the Lake Available online 5 September 2011 Superior-type Cauê Banded Iron Formation, tracks the operation of a Wilson cycle in the Paleoproterozoic Era. The quartz-arenite dominated Espinhaço I and II sequences record at least two major rift-sag basin- Keywords: First-order sequences forming events, which affected the host continent of the São Francisco craton at around 1.75 Ga and Proterozoic 1.57 Ga. The Macaúbas sequence and its correlatives in the extracratonic domains witness the individ- São Francisco craton ualization of a São Francisco-Congo plate in synchronicity with the break-up of Rodinia in the Cryogenian Brazil period.
    [Show full text]
  • 20170601173846853169.Pdf
    Gondwana Research 35 (2016) 40–58 Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr Geologic and geochemical insights into the formation of the Taiyangshan porphyry copper–molybdenum deposit, Western Qinling Orogenic Belt, China Kun-Feng Qiu a,b,⁎,RyanD.Taylorb,Yao-HuiSonga,c,Hao-ChengYua,d,Kai-RuiSonga,NanLia a State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China b U.S. Geological Survey, Box 25046, Mail Stop 973, Denver Federal Center, Denver, CO 80225-0046, USA c Airborne Survey and Remote Sensing Center of Nuclear Industry, Shijiazhuang 050000, China d The 7th Gold Detachment of Chinese Armed Police Force, Yantai 264004, China article info abstract Article history: Taiyangshan is a poorly studied copper–molybdenum deposit located in the Triassic Western Qinling collisional Received 24 January 2016 belt of northwest China. The intrusions exposed in the vicinity of the Taiyangshan deposit record episodic Received in revised form 24 March 2016 magmatism over 20–30 million years. Pre-mineralization quartz diorite porphyries, which host some of the de- Accepted 31 March 2016 posit, were emplaced at 226.6 ± 6.2 Ma. Syn-collisional monzonite and quartz monzonite porphyries, which also Available online 2 May 2016 host mineralization, were emplaced at 218.0 ± 6.1 Ma and 215.0 ± 5.8 Ma, respectively. Mineralization occurred Handling Editor: F. Pirajno during the transition from a syn-collisional to a post-collisional setting at ca. 208 Ma. A barren post- mineralization granite porphyry marked the end of post-collisional magmatism at 200.7 ± 5.1 Ma.
    [Show full text]
  • Alkaline Syenites in Eastern Cathaysia (South China): Link to Permian–Triassic Transtension
    Earth and Planetary Science Letters 230 (2005) 339–354 www.elsevier.com/locate/epsl Alkaline syenites in eastern Cathaysia (South China): link to Permian–Triassic transtension Qiang Wanga,*, Jian-Wei Lib, Ping Jianc, Zhen-Hua Zhaoa, Xiao-Lin Xionga, Zhi-Wei Baoa, Ji-Feng Xua, Chao-Feng Lid, Jin-Long Maa aGuangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China bFaculty of Earth Resources, China University of Geosciences, Wuhan 430074, PR China cGeological Institute, Chinese Academy of Geological Sciences, Beijing 100037, PR China dInstitute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, PR China Received 9 October 2003; received in revised form 15 June 2004; accepted 5 November 2004 Availale online 12 January 2005 Editor: V. Courtillot Abstract Two alkaline syenite plutons, the Tieshan and Yangfang plutons, have recently been recognized within NE-trending fault zones in eastern Cathaysia, South China. The rocks are very enriched in K2O (6.28–9.39 wt.%), rare earth elements (REE; particularly light REE) and large ion lithophile elements, but are relatively low in high field strength elements. Isotopically, they 87 86 are characterized by high initial Sr/ Sr (0.7093 to 0.7123) and low eNd(t) values (À5.64 to À10.63). The geochemical data suggest that the alkaline syenites most likely formed via fractional crystallization of enriched mantle-derived magmas. Sensitive High-Resolution Ion Microprobe zircon U–Pb dating indicates that these two intrusions have Late Permian (254F4 Ma) and Early Triassic (242F4 Ma) crystallization ages, respectively. Our data suggest that a tectonic regime dominated by transtension probably existed from at least the latest Permian into the Triassic and was responsible for the formation of the Tieshan and Yangfang alkaline syenites.
    [Show full text]