Geological Society, London, Special Publications Palaeozoic−Mesozoic history of SE Asia Ian Metcalfe Geological Society, London, Special Publications 2011; v. 355; p. 7-35 doi: 10.1144/SP355.2 Email alerting click here to receive free e-mail alerts when new service articles cite this article Permission click here to seek permission to re-use all or part of request this article Subscribe click here to subscribe to Geological Society, London, Special Publications or the Lyell Collection Notes Downloaded by on August 5, 2011 © The Geological Society of London 2011 Palaeozoic–Mesozoic history of SE Asia IAN METCALFE1,2 1Earth Sciences, Earth Studies Building C02, School of Environmental and Rural Science, University of New England, Armidale NSW 2351, Australia 2National Key Centre for Geochemical Evolution and Metallogeny of Continents (GEMOC), Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia (e-mail: [email protected]) Abstract: SE Asia comprises a collage of Gondwana-derived continental blocks assembled by the closure of multiple Tethyan and back-arc ocean basins now represented by suture zones. Two major biogeographical boundaries, the Late Palaeozoic Gondwana–Cathaysia divide and the Cenozoic-Recent Australia–Asia divide (Wallace Line) are present. Palaeozoic and Mesozoic evolution involved the rifting and separation of three collages of continental terranes from eastern Gondwana and the opening and closure of three successive ocean basins, the Palaeo- Tethys (Devonian–Triassic), Meso-Tethys (Permian–Cretaceous) and Ceno-Tethys (Late Triassic–Cenozoic). This led to the opening and closing of ocean gateways and provision of shallow-marine and terrestrial land bridges and stepping-stones for biotic migration. The SE Asia core (Sundaland) comprises a western Sibumasu block, an eastern Indochina–East Malaya block, and the Sukhothai Island Arc terrane between. The Jinghong, Nan-Uttaradit and Sra Kaeo sutures represent the Sukhothai closed back-arc basin. The Palaeo-Tethys is represented by the Changning-Menglian, Chiang Mai/Inthanon and Bentong-Raub suture zones. The West Sumatra and West Burma blocks were accreted to the Sundaland core in the Late Permian– Early Triassic. SW Borneo and/or East Java–West Sulawesi are now identified as the missing ‘Argoland’ that separated from NW Australia in the Jurassic and accreted to SE Sundaland in the Cretaceous. SE Asia is located at the zone of convergence are fundamental factors leading to both global and between the ESE moving Eurasia Plate, the NE regional climate-change and to important changes moving Indian and Australian Plates and the ENE in biogeographical patterns. Changes in biogeogra- moving Philippine Plate (Fig. 1). SE Asia and phical barriers and bridges caused by geological adjoining regions comprise a complex collage of evolution and consequent climate-change have continental blocks, volcanic arcs, and suture zones also influenced the course of migration, dispersal, that represent the closed remnants of ocean basins isolation and evolution of biota, both globally and (including back-arc basins). The continental blocks in SE Asia. of the region were derived from the margin of This paper provides an overview of the tectonic eastern Gondwana as three successive continental framework, and Palaeozoic and Mesozoic geo- strips or collages of continental blocks that separ- logical evolution and palaeogeography of SE Asia ated in the Devonian, Early Permian and Triassic– and adjacent regions as a background to and to Jurassic and which then assembled during the Late underpin studies of the Indonesian Throughflow Palaeozoic to Cenozoic to form present day East Gateway and the distribution and evolution of and SE Asia (Metcalfe 2005). biota in the region. Global, regional and local Palaeozoic–Mesozoic tectonic evolution resulted in changes to continent– ocean configurations, dramatic changes in relief both Geological and tectonic framework of SE on land and in the seas, and changes in palaeo-ocean Asia and adjacent regions currents, including the opening and closing of oceanic gateways. The significant effect on ocean Mainland East and SE Asia comprises a giant circulation caused by ocean gateway closure/ ‘jigsaw puzzle’ of continental blocks, volcanic arc opening is well documented (e.g. Von der Heydt & terranes, suture zones (remnants/sites of destroyed Dijkstra 2006, 2008). The changes in continent– ocean basins) and accreted continental crust ocean, land–sea, relief, and ocean current patterns (Figs 2 & 3). From:Hall, R., Cottam,M.A.&Wilson, M. E. J. (eds) The SE Asian Gateway: History and Tectonics of the Australia–Asia Collision. Geological Society, London, Special Publications, 355, 7–35. DOI: 10.1144/SP355.2 0305-8719/11/$15.00 # The Geological Society of London 2011. 8 I. METCALFE Fig. 1. Topography and main active faults in East Asia and location of SE Asia at the zone of convergence of the Eurasian, Philippine and Indian–Australian plates. Large arrows represent absolute (International Terrestrial Reference Frame 2000, Altamimi et al. 2000) motions of plates (After Simons et al. 2007). Continental blocks of SE Asia separation from Gondwana, and amalgamation/ accretion to form SE Asia. These are discussed The principal continental blocks located in main- below and the suture zones between them are land SE Asia (Fig. 2) have been identified and described separately. established over the last two decades (e.g. Metcalfe 1984, 1986, 1988, 1990, 1996a, 1998, 2002, 2006) and include the South China block, the Indo- Continental blocks derived from Gondwana china–East Malaya block(s), the Sibumasu block, in the Devonian West Burma block and SW Borneo block (Fig. 3). More recently, the West Sumatra block has been The South China, Indochina and East Malaya blocks established outboard of Sibumasu in SW Sumatra (Figs 2 & 3) are interpreted to have formed part of (Barber & Crow 2003, 2009; Barber et al. 2005) the India–Australian margin of Gondwana in the and a volcanic arc terrane is now identified, sand- Early Palaeozoic and to have rifted and separated wiched between Sibumasu and Indochina–East from Gondwana by the opening of the Palaeo- Malaya (Sone & Metcalfe 2008). A series of Tethys ocean in the Early Devonian (Metcalfe smaller continental blocks are identified in eastern 1984, 1988, 1990, 1996a, b, 1998, 2002, 2005, (maritime) SE Asia and these were accreted to the 2006). The West Sumatra block (originally pro- mainland core of SE Asia in the Mesozoic– posed by Hutchison 1994; Barber & Crow 2003) Cenozoic. and possibly the West Burma block (originally The continental terranes of SE Asia and adjacent called the ‘Mount Victoria Land Block’ by Mitchell regions are here categorized into six types based 1986, 1989) are now also interpreted to have orig- on their specific origins, times of rifting and inally formed part of this collage of terranes PALAEOZOIC–MESOZOIC HISTORY OF SE ASIA 9 YILI-JUNGGAR Terranes derived from NORTHEAST CHINA (COMPOSITE) Gondwana in the 1 2 Devonian TARIM AL NORTH Terranes derived from QD Gondwana in the KL CHINA late Early Permian 10 SUTURES QS Palaeo 1 Tianshan QT SG Indian continent derived 3 9 Pacific 2 Solonker 18 from Gondwana in 11 L 3 Lancangjiang the Cretaceous 21 rehtO niaMsehcnarB naeco SOUTH 4 Changning-Menglian 5 Chiang Mai/Inthanon INDIA CHINA Terranes derived from WB 12 6 Chanthaburi (cryptic) Gondwana in the 4 s 15 Late Triassic-Late Jurassic SI 8 y 7 Bentong-Raub 20 hte 14 LT 8 Song Ma Terranes derived from 5 16 T NI -oeala 9 Qilian-Qinling-Dabie Cathaysialand in the D Carboniferous-Permian 10 Kunlun O Hainan C 11 Jinshajiang 6 UBIS 17 P 12 Ailaoshan Songpan Ganzi NIH accretionary complex 13 Median Sumatra CT A SAM 14 Shan Boundary U Terranes derived from 15 Jinghong 7 E Cathaysialand in the Cretaceous-Tertiary LAM SA S 16 Nan-Uttaradit Arc A T Y Back- 17 Sra Kaeo 19 A 23 13 18 Banggong 22 Meso- Palaeo-Tethys main ocean SWB Tethys 19 Woyla suture: Late Palaeozoic 20 Mawgyi Gondwana - Cathaysia biogeographic divide. WEST SUMATRA Ceno- 21 Indus Yarlung Zangbo Tethys 22 Meratus Proto South China Sea 23 Boyan Fig. 2. Distribution of principal continental blocks, arc terranes and sutures of eastern Asia. WB, West Burma; SWB, SW Borneo block; S, Semitau block; L, Lhasa block; QT, Qiangtang block; QS, Qamdo-Simao block; SI, Simao block; SG, Songpan Ganzi accretionary complex; KL, Kunlun block; QD, Qaidam block; AL, Ala Shan block; LT, Linchang arc terrane; CT, Chanthaburi arc terrane. (which also included North China and Tarim) Arc terranes derived from South China/ that separated from Gondwana in the Devonian Indochina in the Carboniferous–Permian (Barber et al. 2005; Metcalfe 2005, 2009a; Barber & Crow 2009). For more detailed descrip- The Nan-Uttaradit suture, formerly considered to tion of these blocks and assessment of the evidence represent the main Palaeo-Tethys ocean, and to for Gondwana origin see Metcalfe (1988, 1996a, mark the boundary between the Sibumasu and Indo- 2006). china blocks in Thailand, is now regarded as repre- The Late Palaeozoic faunas and floras of these senting a closed back-arc basin (Wu et al. 1995; continental blocks are warm-water, equatorial Ueno 1999; Ueno & Hisada 1999, 2001; Wang Tethyan/Cathaysian Province biotas that contrast et al. 2000). This recognition, and correlation of starkly with temporally coeval cold-water and cold- this suture with the Sra Kaeo suture in southern Thai- climate Gondwana biotas (Metcalfe 2005). This land and the Jinghong Suture in southern China led indicates that these terranes had already separated Sone & Metcalfe (2008) to propose the Sukhothai from Gondwana by Carboniferous times and mig- Arc System derived from the margin of South rated northwards to more equatorial palaeolatitudes. China–Indochina–East Malaya by back-arc spread- This is supported by palaeomagnetic data (Zhao ing in the Late Carboniferous–Early Permian. The et al. 1996; Li & Powell 2001; Li et al.