Formation of marginal seas in Southeast Asia by rifting of the Chinese and Australian continental margins and implications for the Borneo region

Charles S. Hutchison, Department of Geology, University of Malaya, 59100 Kuala Lumpur, Malaysia
1986 Bulletin of the Geological Society of Malaysia  
With the exception s of the Okinawa and Ayu tJOughs, al l the So utheast Asian marginal seas have formed by processes other than back-arc ex tension. The Andaman Sea is an ideal example of a leaky transform system. The West Phi lipp ine Sea, Banda Sea, Celebes Sea and S ulu Sea bas ins 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
more » ... inental margin of Australia. The South Ch in a Sea bas in was probably fo rmed by post-Early Cretaceous riftin g of the continental margin of southeast China and is now trapped behi nd the Mani la arc-trench system. The rifting of Australi a and China, and the associated sea-floor spreadin g, carried continental fragments north wards and southwards respecti vely. Borneo and the adjacent Philippines may have resulted from the .coming together of these fragments to f'orm the heterogeneous basement terrai n over and around which Cenozo ic sed iments have accumulated. The uplift of the margina l sea lithosphere to form ophiolitic terrains is considered to have resulted from the co lli sions of the continental fragments wi th each other or with arc-trench systems.
doi:10.7186/bgsm20198611 fatcat:hmz52ihalrf4vfn4zbjk2yos3y