Dating the birth, growth and death of Miocene carbonate platforms in the South China Sea, Central Luconia Province, Sarawak

The regional distribution, respective location of the Miocene carbonate platforms of Central Luconia and their internal architecture suggest a development initiated and influenced by the late Neogene evolution of the South China Sea. A first regional fragmentation of an extensive carbonate bank probably took place in the early Mid-Miocene (20-15 Ma) period. Series of NE-SW and NW-SE lineaments separating isolated carbonate platforms suggest this regional fragmentation. This event led to the growth of a number of relatively closely spaced isolated platforms, in what is referred to as the "build-up" stage. A second event or series of events probably occurred during the 15-12Ma period, and may have been linked to the last propagator-associated rifting phase that was specific to the southern part of the South China Sea. It is possible that it triggered gravity-induced faulting, which broke up individual isolated platforms. The movements that affected the platforms during this period were subtle and, although platform fragmentation occurred, most platforms were able to heal. A third event, characterized by further fragmentation and rotation of individual platforms may have resulted from gravitational tectonics during the Late Miocene (12-7Ma) period. The slight rotation of individual platforms that occurred during this period resulted in a significant back-stepping of the margins and contraction of the platforms, caused by partial drowning of the subsided part of the platform in what is referred to as the "build-in" stage.