Publications

The Biak Basin is located in Eastern Indonesia, Papua Province, between Biak and Yapen islands. The area is characterised by a complex tectonic history, at the oblique collision zone between the Australian and Pacific Plates. A major strike-slip system, the Sorong - Yapen Fault Zone (SYFZ), bounds the basin to the south. This basin is a frontier area for oil and gas exploration and offshore data are limited. As a consequence, the origin and evolution of this basin is still poorly known. Recently acquired offshore data help constrain the recent history of this basin, allowing detailed seabed imaging and thorough mapping of the various morpho-structural features observed in this tectonically active area. Fault lineaments have been identified, together with submarine depositional features and their generating processes. Modern earthquake activity revealed by public domain data on focal mechanisms highlights remarkable consistency among earthquake mechanisms and some of the morpho-structural features mapped on the seafloor. Earthquake activity seems to be focused in the N and E flanks of the basin, where a series of fault scarps and associated deposits are observed. In areas where limited earthquake activity has been registered, deformation appears to be accommodated by plastic processes. These observations have been integrated with the regional geological interpretation of the SYFZ to constrain the origin and evolution of the Biak Basin. As a general conclusion, deformation is dominated by the presence of the regional SYFZ. However, old inherited structural elements might have played an important role in shaping the basin. Ultimately, these new observations lead to a better understanding of the regional geological history and petroleum system of this novel exploration area.