Mid-Holocene sea-level highstand along the Southeast Coast of China

Abstract

Various sea-level curves have been proposed for the coast of China in the past two decades. These sea-level curves indicate a complex history of Holocene sea level, and so the debate on whether or not a higher mid-Holocene sea-level highstand exists in the coast of China has continued. This paper aims to re-examine the Holocene sea-level history for the low latitude part of the China coast (between 18°N and 32°N) by re-assessing all the sea-level data available from the east to south coasts and separating them according to geological settings in order to examine the influences of global and local factors. The reconstructed sea-level histories from different coastal sectors of the China coast reveal a certain degree of variability in the timing and height of mid-Holocene sea-level highstand. Within large river deltas, the mid-Holocene sea-level highstand occurred earlier by almost 1000 years than that from other coastal sites. The highstand from large river deltas appears also lower in altitude (a few metres below the present-day sea level) due probably to the local factors of subsidence and sediment consolidation. In geologically stable coastal sites, the highstand is recorded at the same altitude as the present-day sea level. A 1–2 m higher highstand is found from sites where tectonic uplift is observed.