Palaeozoic and Mesozoic geological evolution of SE Asia 25 Palaeozoic and Mesozoic geological evolution of the SE Asian region: multidisciplinary constraints and implications for biogeography Ian Metcalfe Division of Earth Sciences, School of Physical Sciences & Engineering, University of New England, Armidale NSW 2351, Australia Key words: SE Asia, geological evolution, terranes, Gondwanaland, Palaeo-Tethys, Meso-Tethys, Ceno-Tethys, biogeography, palaeogeography Abstract Introduction East and SE Asia is a giant jigsaw puzzle of continental Geographic distributions of plants and animals blocks (terranes) which are bounded by faults, narrow mo- in East and SE Asia show complex and evolving bile belts or sutures that represent the sites of former ocean basins" Comparative studies of the tectono-stratigraphy, pal- patterns that are the result of plate movements, aeontology, and palaeomagnetism of the various terranes shifting land/sea and continent/ocean configu- suggests that they were all derived directly or indirectly rations, shifting coastlines, and changing palaeo- from Gondwanaland and that they formed part of a Greater climates and environments( Movements of conti- Gondwanaland" Rifting and separation of three continental nents and continental fragments and the devel- slivers occurred on the northern margin of Gondwanaland, in the Devonian, Early-Middle Permian, and Late Triassic to opment and destruction of oceanic basins dur- Late Jurassic" The northwards drift of these terranes was ing the evolution of the SE Asian region have accompanied by the opening and closing of three succes- resulted in the creation and destruction of bio- sive oceans, the Palaeo-Tethys, Meso-Tethys and Ceno- geographic barriers at various times and the de- Tethys" Amalgamation and accretion of Asian terranes oc- velopment, and disappearance of faunal and flo- curred progressively between the Late Devonian and the Cretaceous, beginning with the intra-Tethyan amalgamation ral provinces( The dispersal and evolution of of South China and Indochina to form Cathaysialand in the faunas and floras of SE Asia are intimately linked Late Devonian-Early Carboniferous, followed by the accre- with the geological evolution of the region( Bio- tion of the Tarim terrane to Kazakhstan/Siberia in the geographic data alone can help to constrain Permian" Suturing of Sibumasu and Qiangtang to Cathaysia- palaeogeographic reconstructions, but recon- land and amalgamation of this super-terrane with North China occurred in the Permian-Triassic, and accretion to structions based on other types of data can also Laurasia was completed by Late Triassic-Early Jurassic times" elucidate observed biogeographic data which The highly disrupted Kurosegawa terrane of Japan, possibly are difficult to understand in terms of present- derived from Australian Gondwana, accreted to Japanese day geography( Eurasia in the Late Jurassic" The Lhasa, West Burma and Woyla terranes, which rifted from NW Australian Mainland East and SE Asia is like a giant jig- Gondwana in the Late Triassic to Late Jurassic were accreted saw puzzle of continental fragments bounded to proto-SE Asia in the Cretaceous" The SW Borneo and by major geological discontinuities that repre- Semitau terranes were derived from the South China/ sent the sites of former ocean basins (Fig(1)( Indochina margin by the opening of a marginal basin in the Some of these major discontinuities are now Cretaceous which was subsequently destroyed by south- wards subduction during the rifting of the Reed Bank-Dan- huge strike-slip faults, whereas others are actual gerous Grounds terrane from South China when the South suture zones that include remnants of oceanic China Sea opened" Following the final breakup of Gondwa- crust (ophiolites), oceanic and continental-mar- naland, India travelled rapidly northwards to make its initial gin sedimentary rocks, accretionary complexes, contact with Eurasia at the end of the Cretaceous" Recon- structions showing the postulated positions of the various melange, and sometimes volcanic arcs( Eastern terranes and the distribution of land and sea in the Palaeo- SE Asia comprises a series of small continental zoic and Mesozoic are presented" fragments set in a matrix of stretched continen- Biogeography and Geological Evolution of SE Asia, pp 25-41 Edited by Robert Hall and Jeremy D Holloway © 1998 Backhuys Publishers, Leiden, The Netherlands 26 Ian Metcalfe KAZAKHSTAN NORTHEAST CHINA (COMPOSITE) 2 3 TARIM QD AL NORTH KL 4 CHINA QI QS SG 8 7 5 KT L 6 SUTURES 1 9 Song Ma SOUTH 2 Aibi-Xingxing INDIA CHINA 3 Xiliao-He WB 16 17 4 Kunlun SI 19 ? 1 Qinling-Dabie 5 12 ? ? 6 Jinshajiang 10 SIBUMASU 7 Lancangjiang INDOCHINA HT 8 Banggong 18 9 Indus Yarlung Zangbo 10 Nan-Uttaradit 11 Raub-Bentong 12 Shan Boundary 11 13 Woyla SIKULEH S 13 14 Meratus 15 15 Boyan NATAL SWB 14 16 Changning-Menglian 17 Ailaoshan BENGKULU 18 Sra Kaeo 19 Southern Guangxi Terranes derived from Terranes derived from Terranes derived from Gondwanaland in the Gondwanaland in the Gondwanaland in the Devonian late Early Permian Late Triassic-Late Jurassic Terranes derived from Indian continent derivedSongpan Ganzi from Gondwanaland in Cathaysialand in the accretionary complex Cretaceous-Tertiary the Cretaceous Fig1 Distribution of principal continental terranes and sutures of East and SE Asia" WB = West Burma, SWB = South West Borneo, S = Semitau Terrane, HT = Hainan Island terranes, L = Lhasa Terrane, QI = Qiangtang Terrane, QS = Qamdo-Simao Terrane, SI= Simao Terrane, SG = Songpan Ganzi accretionary complex, KL = Kunlun Terrane, QD = Qaidam Terrane, AL = Ala Shan Terrane, KT = Kurosegawa Terrane" tal crust or oceanic crust (marginal basins), ac- ago to present) evolution of the region is dis- cretionary complexes, ophiolites and volcanic cussed by Hall (1998 this volume)( arcs (Fig(2)( The various continental fragments In discussing the geological evolution of the (terranes) have progressively assembled over region, a variety of multidisciplinary data (Table 1) the last 400 million years( In this paper, I shall is used here to constrain the origins of terranes; discuss the origins and the Palaeozoic and the timing of rifting and separation from their Mesozoic evolution (540-65 million years ago) parent cratons; timing, directions and amount of of these various continental terranes from a drift; and timing of suturing (collision and weld- multidisciplinary viewpoint and emphasise the ing) of terranes to each other( Some terranes su- importance of, and implications for biogeo- tured to each other (amalgamated) within a ma- graphical data( The Cenozoic (65 million years jor ocean before they, as an amalgamated com- Palaeozoic and Mesozoic geological evolution of SE Asia 27 X X XXXXX X Ailaoshan X 120E X X 1 INDIA X S X C - M X h X X a Song Da n X X XXXXX B X XXXXX 29 o X Song Ma u n X d XX ? 20N a X 20N ? r y X 28 PHILIPPINE X X X SEA PLATE X Nan-Utt. X 5 X X 20 19 X SOUTH X X 2 CHINA X 0 500 km X SEA 15 3 17 10N 10N ANDAMAN SEA LEGEND 16 X Raub-Bentong X X X X X Suture X X X X X Thrust X 18 CELEBES X 8 X X 21 SEA X o i X X X W X d X L Inactive Trench u X o p a A y r X X 22 X l a 4 X 7 X X 0 0 X X Active Trench X X X X B X X o X y 9 X an X 14 Terrane Boundary X X 13 10 X X 6 X Inferred Terrane Boundary X 24 25 11 X X 23 X X X X Oceanic Crust X X s BANDA u X t 12 X ra SEA e X M Accreted Crust 27 10S Extended Continental Crust 26 100E AUSTRALIA 120E Terranes derived from Terranes derived from Terranes derived from Gondwanaland in the Gondwanaland in the Gondwanaland in the Devonian late Early Permian Late Triassic-Late Jurassic Terranes derived from Indian continent derived Terranes derived from Cathaysialand in the from Gondwanaland in New Guinea region in the Cenozoic Cretaceous-Tertiary the Cretaceous Fig2 Distribution of continental blocks and fragments (terranes) and principal sutures of SE Asia (modified after Metcalfe, 1990)" 1" South China 2" Indochina 3" Sibumasu 4" East Malaya 5" West Burma 6" SW Borneo 7" Semitau 8" Sikuleh 9" Natal 10" West Irian Jaya 11" Buru-Seram 12" Buton 13" Banggai-Sula 14" Obi-Bacan 15" North Palawan 16" Spratley Islands-Dangerous Ground 17" Reed Bank 18" Luconia 19" Macclesfield Bank 20" Paracel Islands 21" Kelabit-Longbowan 22" Mangkalihat 23" Paternoster 24" West Sulawesi 25" East Sulawesi 26" Sumba 27" Banda Allochthon 28" Hainan Island terranes" 29" Simao terrane" posite terrane, sutured (accreted) to proto-Asia( South China, and Sibumasu terranes have close affinities with those of eastern Gondwanaland, and especially Australian Gondwanaland Origins of the East and SE Asian terranes (Burrett, 1973; Burrett and Stait, 1985; Metcalfe, 1988, Burrett et al(, 1990)( This is observed in Using multidisciplinary data (Table 1), all the trilobites (Shergold et al(, 1988), brachiopods East and SE Asian continental terranes are inter- (Laurie and Burrett, 1992), corals and stromat- preted to have had their origin on the margin of oporoids (Webby et al(, 1985; Lin and Webby, Gondwanaland, and probably on the India-N/ 1989), nautiloids (Stait and Burrett, 1982, 1984; NW Australian margin( Cambrian and Ordovi- Stait et al(, 1987), gastropods (Jell et al(, 1984), cian shallow-marine faunas of the North China, and conodonts (Burrett et al(, 1990; Nicoll and 28 Ian Metcalfe Table 1 Multidisciplinary constraining data for the origins and the rift/drift/suturing