Sedimentary sequences in response to marine transgression during the late Quaternary, Pearl River delta

The Pearl River Delta, located in the northern South China Sea, has experienced several sea level changes, and deposited several marine-terrestrial strata since the late Quaternary, which provides good research materials for studying the sedimentary model and palaeo-environmental evolution of estuarine and coastal zones. In this study, detailed investigation of lithofacies, grain-size distribution, magnetic susceptibility, microfossils, and chronological analysis were conducted for core GC088. The results were combined with other regional cores and revealed the stratigraphic sequence and the evolution of sedimentary environment in Jiangmen Xinhui area, Pearl River Delta. The Quaternary strata in Xinhui area include six sedimentary facies, namely, river channel, tide-dominated river, estuarine, delta front, tidal flat, and delta plain. Weathered clay layers also present in the Quaternary strata in Xinhui area. Based on the ¹⁴C and OSL dating results obtained in this study and in other cores in the study area, the chronological framework of Xinhui area since the late Quaternary was established. Two transgression-regression cycles in the Pearl River Delta were recognized, and the age of the lower transgression cycle should be attributed to MIS 5.3. The multi-index analysis results of core GC088 illustrate clear periodicity in relation to the sea level change. Combined with the changes of sedimentary facies and the results of other proxies (e.g. geochemical elements, pollen, foraminifera, etc.) of regional cores, it is believed that sea level fluctuated in the MIS 5 stage of the Pearl River Delta. This study indicates that the evolution of sedimentary environment in the Pearl River Delta was mainly controlled by global sea level change and shoreline movement during last glacial-interglacial cycles.