Geological evolution, palaeogeography and tectonics of East and Southeast Asia in relation to the evolution of Gondwanaland and Tethys.
Distribution of principal continental terranes and sutures of East and Southeast Asia. WB = West Burma, SWB = South West Borneo, S = Semitau Terrane, L = Lhasa Terrane, QT = Qiangtang Terrane, QS = Qamdo-Simao Terrane, SI= Simao Terrane, SG = Songpan Ganzi accretionary complex, KL = Kunlun Terrane, QD = Qaidam Terrane, AL = Ala Shan Terrane, LT = Linchang Terrane, CT = Chanthaburi Terrane (from Metcalfe, in press, Geol Soc. London Special Issue)
Distribution of continental blocks, fragments and terranes, and principal sutures of Southeast Asia. Numbered microcontinental blocks, 1. East Java 2. Bawean 3. Paternoster 4. Mangkalihat 5. West Sulawesi 6. Semitau 7. Luconia 8. Kelabit-Longbowan 9. Spratly Islands-Dangerous Ground 10. Reed Bank 11. North Palawan 12. Paracel Islands 13. Macclesfield Bank 14. East Sulawesi 15. Bangai-Sula 16. Buton 17. Obi-Bacan 18. Buru-Seram 19. West Irian Jaya. LT = Lincang Terrane, ST = Sukhothai Terrane CT = Chanthaburi Terrane. C-M = Changning-Menglian Suture, C.-Mai = Chiang Mai Suture, Nan-Utt. = Nan-Uttaradit Suture (from Metcalfe, in press, Geol Soc. London Special Issue)
East and Southeast Asia is a giant "jigsaw puzzle" of continental blocks (terranes) which are bounded by faults, narrow mobile belts or sutures that represent the sites of former ocean basins. Comparative studies of the tectono-stratigraphy, palaeontology, and palaeomagnetism of the various terranes suggests that they were all derived directly or indirectly from Gondwanaland and that they formed part of a "Greater Gondwanaland". Asian continental terranes that are placed on the India-Australian margin of Gondwanaland in the Early Palaeozoic are Tarim (here regarded to include the Kunlun, Ala Shan and Qaidam terranes), Indochina (which includes East Malaya and the Qamdo-Simao block of western China), North China, South China (amalgamated Yangtze and SE South China blocks), Sibumasu, Qiangtang, Lhasa, Kurosegawa, Hainan, West Sumatra, West Burma, and possibly the SW Borneo, East Java, Bawean, Paternoster, Mangkalihat and West Sulawesi microcontinental blocks.
Rifting and separation of three continental slivers occurred on the northern margin of Gondwanaland, in the Devonian (North China, South China, Indochina, Tarim, East Malaya, West Sumatra and West Burma); Early-Middle Permian (The Cimmerian continent including the Sibumasu and Qiangtang terranes); and Late Triassic to Late Jurassic (Lhasa, East Java, SW Borneo, Bawean, Paternoster, Mangkalihat and West Sulawesi microcontinental blocks). The northwards drift of these terranes was accompanied by the opening and closing of three successive oceans, the Palaeo-Tethys, Meso-Tethys and Ceno-Tethys (see above figure).
Amalgamation and accretion of Asian terranes occurred progressively between the Late Devonian and the Cretaceous, beginning with the intra-Tethyan amalgamation of South China and Indochina (to form Cathaysialand) in the Late Devonian-Early Carboniferous which was then followed by the accretion of the Tarim terrane to Kazakhstan/Siberia in the Permian. Suturing of Sibumasu and Qiangtang to Cathaysialand and amalgamation of this super-terrane with North China occurred in the Permian - Triassic, and accretion to Laurasia was completed by Late Triassic-Early Jurassic times. The West Burma and West Sumatra blocks were derived from Cathaysialand in the Permian, probably by back-arc spreading and translated to their current positions outboard of Sibumasu by large scale transcurrent movements. The highly disrupted Kurosegawa terrane of Japan, possibly derived from Australian Gondwana, accreted to Japanese Eurasia in the Late Jurassic. The Lhasa, East Java, Bawean, Paternoster, SW Borneo and West Sulawesi blocks, which rifted from NW Australian Gondwana in the Late Triassic to Late Jurassic were accreted to proto-Southeast Asia in the Cretaceous. Following the final breakup of Gondwanaland, India travelled rapidly northwards to make its initial contact with Eurasia at the end of the Cretaceous. The persistent rifting from Gondwanaland and northwards translation of continental terranes with the consequent opening and closing of successive Tethyan ocean basins has major implications for palaeobiogeography and for understanding observed distributions of SE Asian faunas and floras in the Palaeozoic and Mesozoic. Palaeogeographic reconstructions showing the postulated palaeo-positions of the various terranes and the distribution of land and sea in the Palaeozoic and Mesozoic are presented.
Click the following to view palaeogeographic reconstructions showing the relative positions of Asian terranes with respect to Gondwanaland, Pangea and Tethys during the Phanerozoic:
Cambro-Ordovician (Tremadoc) Palaeogeography
Late Devonian-Lower Carboniferous Palaeogeography
Early Early Permian (Asselian-Sakmarian) Palaeogeography
Late Early Permian (Kungurian) Palaeogeography
Late Permian Palaeogeography
Late Triassic Palaeogeography
Late Jurassic Palaeogeography
Early Cretaceous Palaeogeography
Late Cretaceous Palaeogeography
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