Publications

The Seram Fold-Thrust Belt (SFTB) is an E-W trending thrust system that cuts along Seram Trough since the Early Pliocene, confirmed by its activities during the deposition of Early Pliocene sequence. This thrust system is related the development of Misool-Onin-Kumawa Anticline (MOKA) which was active while the collision in the Bird’s Head area started. The main objectives of this research are the timing of formation the SFTB and MOKA, as a part of tectonic evolution of Bird’s Head region, Papua. More than 200 seismic lines have been interpreted along the Misool, Onin, Kumawa, and Seram offshore. These interpretations showed the development of fold-thrust belt structure at Seram Trough area as the evidence of the SFTB activities, which repeated the Mesozoic-Miocene sequences, with the detachment surface located between Seram and Seram Trough and cut into Paleozoic-Triassic sequences. Reverse faults at Mesozoic through Miocene sequences in the north of the trough and the Misool area are reactivated normal faults formed during the NW shelf of Australia rifting since the Mesozoic. In addition, the evolution of the SFTB and MOKA is associated with the rotation and translation of the Sorong Fault Zone (SFZ) activities to the northwest indicated, by the NE-SW shortening of the Bird’s Head area. The reverse faults in the north and south of MOKA suggested a reactivation fault that developed MOKA. New seismic interpretation combined with the 2D palinspatic reconstructions suggests that SFTB and MOKA mechanism is not only related to the rotation and translation phase from the SFZ activities but also combined with additional westward movement of Tarera-Aiduna strike-slip system to west in particular formation of SFTB. These deformations mechanism are active since the Late Miocene as the result of the collision between the Pacific island arc complexes and the passive margin of the NW Australia plate.