The middle-to-late Holocene relative sea-level history, highstand and levering effect on the east coast of Malay Peninsula

Abstract

This study was conducted to (1) investigate a former mangrove wetland on the east coast of Peninsular Malaysia near Kuantan and produce new sea-level index points (SLIP), and to (2) re-analyzed the modern vegetation and pollen results from a mangrove-swamp transect within the nearby estuary to establish the relationship between vegetation zones and tidal levels for estimating indicative meanings (IM) for the SLIPs. The results indicate that the modern floral and pollen zones match well with the fossil ones, and four IMs were appropriately established. Combining with the recently published SLIPs from Terengganu, the 15 new SLIPs from Kuantan were used to reconstruct the middle-to-late Holocene relative sea-level (RSL) history for the east coast of the Malay Peninsula. This history shows that the RSL reached c. 1.5 m msl around 6500 cal. a BP and rose to c. 2.0 m msl by 4500 cal. a BP. This phase of RSL rise in this far-field site supports the hypothesis that additional ice melting occurred between 7000 and 4000 cal. a BP. During this phase of RSL rise, erosion and redeposition of estuarine sediments occurred at the study site. Since 4000 cal. a BP, the RSL fell gradually to below the present height by 800 cal. a BP. In general, this RSL history matches well with the GIA model with the ICE4G melting history. Furthermore, the SLIPs from the east coast are systematically lower in elevation than those recorded in the west coast. The difference is about 1.5 m in the beginning of the middle Holocene and it decreases gradually towards the late Holocene. This difference, thus, implies the existence of continental levering during the Holocene.