Reversal in Structural Transport Direction in the NW Borneo Deep Water Fold-and-Thrust Belt

The analysis of the geometry, vergence and growth history of the NW Borneo deep-water fold-and-thrust belt in this study using three-dimensional (3D) seismic data, leads to the establishment of the three phases of fold development which related to the early fold development of the tectonic phase, the early phase of the gravitational sediment loading and the phase of the gravitational driven fold development The first phase begins with the controlling factor of subduction towards the Southeast, forming the initial anticline vergence towards Sabah, and sediment deposition from the Dangerous Grounds in the Northwest. The next phase involved the development of symmetrical structures in the Middle Miocene, as the Crocker Ranges started supplying sediment towards the basin. The final phase was gravity-driven development, causing thrusting and rapid growth of the folds as huge and continued sediment volumes were transported towards the basin to the Northwest. The results presented in this research demonstrate that 3D seismic data can be a powerful tool in our understanding of deepwater fold and thrust belt systems, and that linking structural and stratigraphic investigations can provide new insights into the interactions between deformation and sedimentation.