Late Quaternary tectonics, sea-level change and lithostratigraphy along the northern coast of the South China Sea

Abstract

AbstractThis paper examines the Late Quaternary evolutionary history of the northern coast of the South China Sea by reviewing geological evidence from this coast. Results show that: (1) a lithostratigraphy with two marine sequences is observed in the deltaic basins of the Song Hong, Pearl and Han rivers, and these basins are all bounded by active faults; (2) whilst the upper marine sequence belongs to the present interglacial or the past 10.5 ka, the lower or older marine sequence was most likely deposited during the high sea level of the last interglacial period, c. 126–120 ka; (3) the burial depth of the older marine sequence is recorded at −15 m below modern sea level or deeper, implying localized subsidence of varying rates between these deltaic basins because the height of sea level during the last interglacial was close to that of the present; (4) this tectonic process is probably associated with the continuous long-term subsidence of the northern South China Sea continental shelf within the tectonic framework of southward continental extension of the Eurasian Plate during the Cenozoic; (5) fault activity has enhanced the localized subsidence of these deltaic basins, which led to marine inundation during interglacial high sea levels.