An Evolutionary Model of the Near-shore Tinjar and Balingian Provinces, Sarawak, Malaysia

The tectonic evolution of a basin can hold vital information regarding the variations and changes in depositional environments. Sarawak basin has undergone strong tectonic activity in its past. In this study, a model has been proposed for the evolution of Tinjar and Balingian provinces in Sarawak, East Malaysia in order to throw light on tectonic events that was responsible for basin development. The model was developed by balancing and restoration of cross sections obtained from published interpreted seismic profiles. The model takes into account the subduction of proto-South China Sea oceanic crust beneath the Borneo plate during Middle Eocene to Middle Miocene. The resulting model depicts older sequences (T1S and T2S) were accreted on to Borneo continental plate as a wedge and younger sequences (T3S) as piggyback basins. Due to structural complexity and variability of the region, each tectonostratigraphic province of Sarawak should be analysed individually as the proposed model corresponds only to two provinces of Sarawak.