Publications

The Kumawa and Aru basins are part of a narrow extensional system within the Aru trough in the northern Australian continental margin, located east of the U-shaped Banda Arc–Australia boundary. The study area is bounded by the Misool–Onin–Kumawa Ridge and Lengguru fold belt to the north, the Seram fold and thrust belt to the west, the Aru shelf to the east, and it connects to the Tanimbar trough to the southwest. Interpretation of 2D seismic and multibeam bathymetry data shows the Neogene history of extension. In the west of the study area the Kai Arch is a horst block bounded on its west side by the frontal thrust of the offshore Seram fold and thrust belt. The east side of the study area is bounded by a major normal fault downthrown to the east. The arch is capped by a carbonate platform now at depths of almost 1 km. East of the Kai Arch, there are more than 5 seconds TWT of Upper Miocene to Recent sediments. Structures are dominated by N-S to NNE-SSW-trending normal faults which can be traced SSW into the Tanimbar trough. The normal faults terminate in the north at a WNW-ESE-trending fault, which is partly buried beneath disturbed sediments transported into deeper water from the shelf south of the Lengguru fold belt. The Tarera-Aiduna fault zone is imaged on the seabed and dies out to the west, south of the Lengguru fold belt. It is a young structure with little displacement. Basin formation started during the Late Miocene and the basin underwent several periods of subsidence, marked by multiple unconformities within the syn-extension units. There is petroleum potential with three possible plays: (1) Mesozoic sandstone reservoirs in tilted fault blocks, (2) Cenozoic carbonates at the edge of the Kumawa and Aru basins, (3) Upper Miocene Klasafet Formation in the Seram fold and thrust belt.