TECTONIC DIFFERENTIATION IN THE EASTERN PART OF SARAWAK BASIN AND ITS CONTROL OVER SEDIMENTATION

Based on the tectonic evolution of the Sarawak Basin, the tectonic differentiation among North Luconia, Central Luconia and Balingian provinces and its control on sedimentation are discussed in this paper. It shows that:1) the subduction and collision of Luconia to Borneo plate, dominated by Borneo's anti-clockwise movement, was the main factor that leads to the tectonic differentiation among North Luconia, Central Luconia and Balingian provinces; 2)sedimentation was controlled by the tectonic differentiation:a) From Middle Miocene to Upper Miocene, Paleotopography dominated the type of sediments. The Central Luconia province was dominated by carbonate sedimentation, while Marine clastics were deposited in the North Luconia and Blingian provinces; b) Despite the intensity of deformation in surrounding areas, the basin remained stable throughout the time of Tertiary to facilitate the carbonate deposition; c) From Oligocene to early Miocene, due to the extensional and strike-slip tectonics, this area formed the southwest to northeast trending graben and horst which dominated the type of carbonate buildups and their distribution