Publications

New seismic and multibeam data from the South Banggai-Sula area suggest that many previously reported structures may have been misidentified. This paper presents a revised tectonic map of the region. Based on correlation with geology on land it is suggested the area north and west of the North Banda Basin is underlain by Paleozoic to Permo- Triassic Australian-origin basement rocks, overlain by Mesozoic–Early Miocene sedimentary rocks. Collision in the Early to Middle Miocene preceded extension that led to formation of the North Banda Basin in the Late Miocene and more recent extension that may continue to the present-day. Strands of the Sorong Fault can be traced from New Guinea towards the Sula Islands but there is no through-going Sorong Fault Zone traceable to the south of the Banggai-Sula block. Instead there is a highly extended continental margin north of the North Banda Basin which is underlain by Middle Miocene–Pliocene (12.5–7.3 Ma) oceanic crust. Seismic data suggest there is a narrower area of oceanic crust between Mangole and Buru Island, interpreted to be of similar age to the North Banda Basin. West of the Sula Islands the Matano Fault Zone observed on land in East Sulawesi appears to terminate in the NW corner of the North Banda Basin. Adjacent to the Tolo Trough there is a probable large-scale gravitational collapse structure. The existence of the Greyhound Straits Fault between Taliabu and Banggai Island is doubtful. The absence of a major through-going strike-slip fault zone along the south Taliabu Shelf indicates that the Banggai-Sula block was not transported to the west by the Sorong Fault Zone.