Holocene coastal response to monsoons and relative sea-level changes in northeast peninsular Malaysia

摘要

Sedimentological, geomorphic, and ground penetrating radar (GPR) data are combined with optically stimulated luminescence data to define the Holocene evolution of a coastal system in peninsular Malaysia. The Setiu coastal region of northeast Malaysia comprises five geological and geomorphic units representing distinct evolutionary phases of this coastline. Estimated marine limiting point elevations indicate deposition of an early aggradational shoreline associated with a sea-level elevation of-0.1 to +1.7 m (MSL_(pmvgd) datum) between ～6.8 ka and 5.7 ka, in agreement with previous sea-level studies from the Malay-Thai peninsula. A hiatus occurs in the record between ～5.7 ka and 3.0 ka, possibly due to a relative sea-level oscillation and shoreline erosion. Long-term relative sea-level fall and possible still-stands created strandplains that are interrupted by aggradational to transgressive paleo-barrier and estuary formation corresponding with brief episodes of RSL rise. Analyses of GPR facies and OSL ages suggest annual clinoform deposition, with geometries dictated by variations in ENSO. These data demonstrate the utility of high resolution studies of coastal facies as useful proxy indicators for paleoclimate studies at subdeca-dal to millennial time-scales.