ABSTRACT: Tectonic evolution of East and SE Asia: Pre-Cenozoic background
Metcalfe, Ian , University of New England, Armidale, Australia
East and Southeast Asia comprises allochthonous continental fragments (terranes), bounded by suture zones that represent the remnants or sites of former ocean basins. The principal East Asian terranes were located on the India-Australian margin of Gondwanaland in the Early Palaeozoic forming a "Greater Gondwanaland". Pre-Cenozoic tectonic evolution involved the rifting and separation of three elongate continental slivers/collages of terranes from Gondwanaland, their northwards drift and subsequent amalgamation and accretion to form proto-East Asia. Asian terranes rifted and separated from NW Australian Gondwanaland as three continental slivers, in the Devonian (North & South China, Indochina, Qaidam, Tarim and Hainan terranes); Early-Middle Permian (Cimmerian continent including the Sibumasu and Qiangtang terranes); and Late Triassic to Late Jurassic (Lhasa, West Burma). During the separation of these continental slivers, three ocean basins, the Palaeo-Tethys, Meso-Tethys and Ceno-Tethys, opened between each successive sliver and Australian Gondwanaland. Amalgamation and accretion of Gondwanaland-derived Asian terranes occurred progressively between the Late Devonian and Cretaceous. The SW Borneo and Semitau terranes were derived from the South China/Indochina margin by the opening of a marginal basin in the Cretaceous.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia