Publications

During Paleogene, the western part of Indonesia is represented by the existence of numerous rift basins. The tectonics of the rifting phase during Paleogene has been an interesting issue for many years. Several authors had different opinions about this issue. Some thought that the rifting system along the western margin of Sundaland is purely extensional, caused by the mantle upwelling during the Miocene orogeny and others thought that the rifting system is more likely controlled by strikeslip faulting, possibly caused by the difference of plate movements during Pre-Tertiary to Eocene. The existence of thermal anomalies within on several grabens oriented parallel to the subduction zone has made some believe that western Indonesia is a back arc basin during the rifting phase. The weakness of this theory is because many of the other grabens do not parallel to the subduction zone. On the other hand, the available strike-slip theory has not clearly explained different graben orientations on each of the Paleogene rift basins in the Western Indonesia. Even though the rifting can be explained resulting from strike-slip faulting, the different orientations have concluded seemingly that each basin in the western Indonesia was developed by different tectonic system during the Eocene-Early Miocene.From our sandbox modeling, we discovered that pre-existing basement structures are a fundamental control element of rifting. These pre-existing structures acted as mechanical discontinuities, which controls the strain distribution because of applied stress. This model fit with the observation of rift basin in the western Indonesia.