Aspects of the geological development of the Makassar Strait, Indonesia

Abstract

The Makassar Strait is a Cenozoic extensional deep-water basin bounded to the east by Borneo and the Mahakam Delta system, to the west by Sulawesi, to the north by a zone of deformation associated with strike-slip movements and the North Sulawesi Fold-and-Thrust Belt, and to the south by the Paternoster Platform. It comprises a maximum of 7 km of Paleogene shallow-to non-marine synrift sedimentary rocks and volcanics, and Paleogene to Neogene post-rift deep-water sediments overlying a basement of attenuated continental crust with volcanics. Early Miocene uplift of Borneo resulted in the deposition of large volumes of Neogene sediment in the Kutai Basin, some of which was remobilised from the Mahakam Delta and deposited in east-directed fan systems in the Makassar Strait. Pliocene tectonic events in west Sulawesi formed the West Sulawesi Fold Belt and west-directed turbidites in the central and eastern Makassar Strait. Current turbidite sedimentation in the central part of the strait is north directed through the Makassar Fan, and primarily sourced from the Lariang River in west Sulawesi.