Bulletin of the Geological Society of Malaysia, Volume 20, August 1986, pp. 201 - 220
Department of Geology, University of Malaya, 59100 Kuala Lumpur, Malaysia
Abstract: With the exceptions of the Okinawa and Ayu troughs, all the Southeast Asian marginal seas have formed by processes other than back-arc extension. The Andaman Sea is an ideal example of a leaky transform system. The West Philippine Sea, Banda Sea, Celebes Sea and Sulu Sea basins all appear to be remnants of former oceans now trapped behind younger arc-trench systems. The last three may be interpreted to be related to the post-Early Triassic rifting of the northern continental margin of Australia.
The South China Sea basin was probably formed by post-Early Cretaceous rifting of the continental margin of southeast China and is now trapped behind the Manila arc-trench system. The rifting of Australia and China, and the associated sea-floor spreading, carried continental fragments northwards and southwards respectively. Borneo and the adjacent Philippines may have resulted from the .coming together of these fragments to form the heterogeneous basement terrain over and around which Cenozoic sediments have accumulated.
The uplift of the marginal sea lithosphere to form ophiolitic terrains is considered to have resulted from the collisions of the continental fragments with each other or with arc-trench systems.