The aim of this project was to investigate the contribution of Cenozoic regional tectonics of the Bird’s Head region of West Papua, Indonesia in the developmental history of the Biak Basin. Comparisons were made to proven petroleum systems in other basins within the Bird’s Head to assess the viability of any possible petroleum system within the Biak Basin.
The Biak Basin is a frontier region, located between the islands of Biak to the north and Yapen to the south. The basin is bounded by the Biak Array, a series of parallel NW-SE trending strike-slip faults to the east, the Yapen Fault to the south, and by a basement high that forms the Numfoor Ridge to the west. The basin is filled with up to 7km of mainly Neogene strata. The island of New Guinea was part of the northern Australian passive margin until the end of the Paleogene. In eastern New Guinea there was collision between intra-Pacific island arcs that formed above a northward-dipping subduction zone and the Australian passive margin in the Early Miocene (earliest Aquitanian). The suture of this collision is presently marked by the Ransiki Fault of the eastern Bird’s Head and can be traced into Cenderawasih Bay, east of the Wandamen Peninsula, and linking with the Weyland Overthrust in the New Guinea Central Ranges. During the Neogene, convergence of the Pacific and Australian plates was accommodated by contractional tectonics in the New Guinea Central Ranges, and by extensional tectonics and strike-slip deformation in the accreted arcs. Extension during the Middle Miocene propagated in the direction of the minimum compressive stress from the convergence of these plates and caused widespread basin subsidence and carbonate platform drowning.