Uncovering paleoenvironmental evolution in Xinghua Bay of Southern China during the mid-to-late Holocene, insights from studies of biogeochemical elements in sediments

• Published in: Journal of paleolimnology 2024-12, Vol.72 (4), p.365-379
• Main Authors: Wang, Jinrong, Xu, Xin, Chi, Lianbao, Li, Xin, Wang, Yongchao, Jiang, Miaohua, Chen, Jianming, Li, Jing, Fan, Xin
• Format: Article
• Language: English
• Subjects: Biogeochemistry; Carbon 13; Carbon isotopes; carbon radioisotopes; China; Climate; Climate Change; cold; Cold weather; Earth and Environmental Science; Earth Sciences; Environmental changes; Evolution; Fluctuations; Foraminifera; Freshwater & Marine Ecology; Geology; Global climate; Grain size; Holocene; Holocene epoch; monsoon season; Monsoons; Organic carbon; Original Paper; paleoecology; Paleontology; Physical Geography; Radiocarbon dating; Sea level; Sea level changes; Sediment; Sedimentology; Sediments; spectrometers; Strata; subsidence; Total organic carbon
• ISSN: 0921-2728; 1573-0417
• DOI: 10.1007/s10933-024-00337-9

The long-term sequestration of biogeochemical elements in the sediment of inner bays can effectively record changes in ancient climate environments. Nevertheless, our understanding of the responses of biogeochemical elements to environmental shifts remains insufficient. By analysing the multi-proxy data from an 1800-cm long sediment core from Xinghua Bay, the paleoenvironmental changes during the mid-to-late Holocene were elucidated in this study. The chronology of 5.9 cal ka BP was established from six accelerator mass spectrometer (AMS) radiocarbon dates on foraminifera. A thin terrestrial stratum (1700–1800 cm) and a thick marine stratum (0–1700 cm) were recognized. It is inferred that at approximately 5.9 cal ka BP, the study area underwent a transition from land to ocean due to geological subsidence. According to analyses of the TOC, TN, BSi, δ 13 C and grain size, the patterns of paleoenvironmental changes in the marine sedimentary layer are as follows: 5.9–5.2 cal ka BP, warm, fluctuating sea-level rise; 5.2–3.6 cal ka BP, cold, decreasing sea-level fluctuations; 3.6–3.3 cal ka BP, small sea-level rise, warm climate; and 3.3 cal ka BP-present, cyclical warm and cold climates, small fluctuations in sea level. Additionally, the changes in the terrestrial/marine organic carbon contribution of core ZK5 corresponded with fluctuations in the East Asian monsoon, indicating that the East Asian monsoon played a substantial role in determining the origin of organic material in Xinghua Bay throughout the mid-late Holocene. The records of environmental evolution in Xinghua Bay match well with those of coastal South China, which has a good response to regional environmental changes and global climate events. The results provide new perspectives and substantial evidence for understanding the response of biogeochemical elements in the inner bay region to environmental changes.