| Abstract: |
Remnants of the Palaeo-Tethys ocean are preserved within a number of suture zones that separate allochthonous continental terranes in East and Southeast Asia. The main Palaeo-Tethys ocean is represented by the Lancangjiang and Changning-Menglian sutures in Tibet and Yunnan, and the Nan-Uttaradit and Bentong-Raub sutures in Thailand and Malaysia respectively. To the west of these sutures, terranes exhibit Gondwanaland faunas and floras and marginal Gondwanaland stratigraphies up until the Lower Permian. To the east, the terranes exhibit Lower Palaeozoic Gondwanaland faunas but Tethyan/Cathaysian Late Palaeozoic faunas and floras show no evidence of Gondwanaland related stratigraphy in the Late Palaeozoic. Other branches of the Palaeo-Tethys are represented by the Ailaoshan suture in Yunnan and the Song Ma suture in North Vietnam. New data from the Palaeo-Tethys remnants along these sutures, particularly in Yunnan, Thailand, Malaysia, suggest that the Palaeo-Tethys opened in the Devonian when the first of three continental slivers rifted and separated from northern Gondwanaland. It is proposed that this continental sliver comprised North China, South China, Tarim, Indochina, Qaidam and Hainan. The branch of Palaeo-Tethys which separated South China and Indochina closed by Early Carboniferous times in its eastern part along the Song Ma suture, but much later in the west along the Ailaoshan suture during the Triassic. Radiolarian biostratigraphic and other data suggest that the main Palaeo-Tethys was closed when the Sibumasu-Qiangtang terranes amalgamated with Indochina/South China in the Triassic. Ongoing problems relate to the correlation and contiguity of the Palaeo-Tethyan sutures in south Yunnan, northern Thailand, Laos, Burma, and Vietnam.
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