NEOGENE TECTONIC AND SEDIMENTARY CONTROL TO HYDROCARBON GENERATION IN BANYUMAS SUB-BASIN, SOUTH OF CENTRAL JAVA

摘要

Banyumas Sub-basin is located on the southern volcanic belt of Java where petroleum exploration just recently began after stopped for a quite long time. The initial tectonic activity that influenced basin formation and architecture was the late Cretaceous-Oligocene subduction. The subduction process followed by the isostatic equilibrium during late Oligocene. Two main faults existence which have opposite trends : Muria-Kebumen Sinistral Fault trending SW-NE and Pamanukan-Cilacap Dextral fault trending NW-SE, respectively marked the isostatic process. These two faults assumed had sunk the northern part of Central Java and as the isostatic compensation also uplift the southern part because of the convergence of those opposing faults; it is proved by bouguer anomaly data +110 mgal on the southern side and gradually decreasing to -5 mgal at the northern side. Besides, these two faults phenomena also influenced the sub basins formation, one of them is Banyumas Sub-basin.