Myanmar and Asia united,Australia left behind long ago |
| |
| Institution: | 1. SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, Egham TW20 0EX, UK;2. London Geochronology Centre, Department of Earth Sciences, UCL, Gower Street, London WC1E 6BT, UK;3. Myanmar Geosciences Society, 303, MES Building, Hlaing University Campus, Yangon, Myanmar;4. Soulieysset, La Salvetat Peyrales, 12440, France;1. SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK;2. Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia;1. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China;2. School of Earth Sciences, China University of Geosciences, Wuhan 430074, China;3. Earth Sciences, Earth Studies Building C02, School of Environment and Rural Science, University of New England, Armidale, NSW 2351, Australia;1. EarthByte Group, School of Geosciences, The University of Sydney, NSW 2006, Australia;2. Oil Search Limited, Sydney, NSW 2000, Australia;3. Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USA;1. Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Beijing 100101, China;2. Department of Geosciences, University of Arizona, Tucson, AZ, USA;3. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;4. Myanmar Geosciences Society, Yangon, Myanmar;5. Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China |
| |
| Abstract: | It is well known that western Myanmar is underlain by a continental fragment, the West Burma Block, but there are arguments about its origin and the time of its arrival in SE Asia. This study presents the first petrological, XRD diffraction, heavy mineral and detrital zircon U-Pb age data from turbidite sandstones in the Chin Hills that were deposited on West Burma crust in the Triassic. These sandstones contain detritus derived from areas surrounding West Burma and thus help resolve arguments about its location in the Palaeozoic and Mesozoic. West Burma, Sibumasu and Western Australia have similar populations of Archean zircons derived from Western Australian cratons. Until the Devonian all formed part of the Gondwana supercontinent. The abundance of Archean zircons decreases from Western Australia to West Burma and then to Sibumasu. This is consistent with their relative positions in the Gondwana margin, with Sibumasu furthest outboard from Western Australia. Differences in zircon populations indicate that Indochina was not close to West Burma or Sibumasu in Gondwana. West Burma contains abundant Permian and Triassic zircons. These are unknown in Western Australia and different from those of the Carnarvon Basin; they were probably derived from SE Asian tin belt granitoids. Cr spinel is present in most West Burma sandstones; it is common in SE Asia but rare in Western Australia. These new data show that West Burma was part of SE Asia before the Mesozoic and support suggestions that the Argo block that rifted in the Jurassic is not West Burma. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
