Publications

Interpretation of new high quality multibeam and 2D seismic data from the north Banggai-Sula area, which lies in eastern Indonesia between Sulawesi and the Banda Sea, has led to a better understanding of this previously poorly explored area. A new structural map differs significantly from previous interpretations. There is no evidence of the continuous E-W-trending North Sula-Sorong Fault shown on many maps, if it exists it terminates between Obi and Mangole, at the eastern end of the Sula Islands. The NW-trending Greyhound Strait fault, previously considered to lie between the Banggai and Sula Islands, has no seafloor expression, and cannot be identified in the study area. A zone of broadly south-directed thrusting, previously termed the Sula Thrust, lies along the foot of the north-dipping continental slope. However, it is diffuse, variable in orientation and genesis, and no major through-going thrust zone exists. Northwest of Taliabu, thrusting is related to a transpressive dextral strike-slip fault system, probably the termination of a WNW-trending strikeslip fault which crosses Sulawesis Poh Head. To the east, north of Mangole, thrusting is related to convergence between a complexly deformed wedge of sediments squeezed out of the Molucca Sea collisional zone, and the continental slope. The Banggai-Sula microcontinental margin has been tilted northwards under this south-propagating wedge, causing large fragments of the slope to slide into the deep basin to the north. Significant subsidence is indicated by probable Miocene platform carbonates now at water depths of more than 1 km. There are possible carbonate and clastic hydrocarbon reservoirs, associated with abundant shales that are potential source rocks, which could also provide seals. Widespread faulting, folding and inversion mean that numerous small but viable hydrocarbon targets may exist.