1064 / 2024-09-20 10:15:48

Core sediment chronology and its insights into delta processes for the Pearl River Delta

OSL dating,Pearl River Delta,sedimentary history,sea level change,human activity

Delta formation is influenced by the sea level, river forces, and human activities. The Pearl River Delta (PRD) is one of the three major deltas in China with dense population. Studying its delta evolution is of great significance to urban construction, and Chronology is the key in these researches. Previous studies have primarily relied on radiocarbon dating (¹⁴C dating), whose application is constrained by the reservoir effect and the scarcity of dating materials. Optically stimulated luminescence (OSL) dating is widely used because of abundant materials (e.g., quartz or feldspar) and larger dating range. However, there is still limited OSL data reported, especially in the northeastern PRD (Dongguan Basin), which impedes the overall understanding of the delta history. Here, we present 13 quartz OSL ages from the upper 13 m of core SXG07 from the Dongguan Basin. The results suggest: (1) The luminescence ages ranged from 216 to 0.14 ka. (2) Three hiatus were detected with age gaps of >216-23 ka, 13.6-9.1 ka, and 9.1-1.43 ka. (3) The hiatus with an age gap of 9.1-1.43 ka might be attributed to strong scouring of local tidal processes, as revealed by coarse-to-fine transition in grain size; (3) Since 1.43 ka, human activities rapidly increased, resulting in a fast deposition of ~5 m/ka.