The Palaeo-Tethys in East Asia

Abstract

The main branch of Palaeo-Tethys in East Asia is represented by the Lancangjiang and Changning-Menglian suture zones of western China, the Nan-Uttaradit and Sra Kaeo suture zones of Thailand and the Bentong-Raub suture zone of Peninsular Malaysia. Other subsidiary branches are represented by the Jinshajiang, Ailaoshan and Song Ma suture zones of western China and Vietnam and the Qinling-Dabei suture zone of north and central China. A further possible Palaeo-Tethyan suture zone segment has also been recognised in southern Guangxi, south China. New data from the Palaeo­ Tethys remnants along these sutures, particularly in Yunnan, Thailand and Malaysia, suggest that the Palaeo-Tethys opened in the Devonian when the first of three continental slivers (comprising North China, South China, Tarim, Indochina and Hainan) rifted and separated from northern Gondwanaland. 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 Permian-Triassic.