Response Of Incised Valley Systems With Sea Level Change During Late Pleistocene-Holocene At Penyu Basin, Sunda Shelf

Abstract

Valley incision and infilling, as well as the fluvial response of uppermost Pilong formation in Penyu Basin located offshore of present-day Pahang River Basin, Peninsular Malaysia during Late Pleistocene-Mid Holocene was studied. A detailed study of time slices, horizon surfaces and vertical sections of three-dimensional (3D) volume data, high-resolution two-dimensional (2D) CHIRP acoustic profiles, and seabed bathymetric data provided a very good opportunity to delineate the changes of the deglacial fluvial pattern as well as its internal morphology and its evolution through geologic time. Based on the fluvial origin, plan-view pattern and internal architecture, six classes of deglacial fluvial sequences have been categorized.

The lowermost sequence is classified as straighter incised valley system with incised dendritic tributary valley system that is characterized by braided channel system followed by high sinuous meander belt associated with confined meander channel system. Later, fluvial regress response from meander belt to a braided valley system