Borneo Oroclinal Bending, The New Paradigm

The paper highlights an alternative tectonic model of Borneo, namely ‘Borneo Oroclinal Bending’, and its subsequent tectonic deformation throughout Sabah and Sarawak Basins. This model assimilates regional onshore structural interpretation to offshore structures, onshore to offshore stratigraphic findings by incorporating information from latest exploration wells and play concepts; to rejuvenate exploration activities in Borneo basins which seems to be nearing matured. We interpreted tectonostratigraphic link between onshore to offshore northern Borneo using subsurface seismic interpretation and surface lineaments of onshore Sabah Sarawak, and whole Borneo. Our main findings thus can be summed into five (5) points; the opening of South China Sea may actually have minimal impact on development of Borneo Oroclinal Belt; Borneo are internally deformed than bulk rotated due to episodic tectonic event of indentation resulting into relic Sarawak Orogeny and ongoing Sabah Orogeny; Sabah orogeny (+/− 17Ma to Present day) are resulted from northwestward indenting motion of Sula Spur as results from Australia/Pacific Collision; Sarawak orogeny (+/−55 Ma to +/−17Ma) are resulted from eastward indenting motion of Proto-South Java Sea spur; and finally and both Sabah and Sarawak Basin developed purely as flexural basin, resulting from propagating far-field tectonic stress along Sunda periphery