Transgression–regression processes since the MIS 3 in the coastal zone of Quanzhou Bay, Fujian

Abstract

The coastal zone is sensitive to sea–land interaction, making it an ideal place to study the transgression–regression process in Quaternary coastal areas. Based on the stratigraphic and lithologic characteristics of two Quaternary drill cores (DZ01 and DZ02) in the coastal zone of Quanzhou Bay, Fujian Province, a stratigraphic chronological framework was established by using AMS-14C and OSL dating methods. Combined with the statistical analysis results of geochemical element content of indicating facies in modern sediments in Quanzhou Bay, the geochemical element ratios, foraminifers, and ostracods' environmental indicators were used to identify transgressive strata since the Late Pleistocene. The transgression–regression processes since the MIS 3 in Quanzhou Bay were analyzed by comparing it with the regional borehole data. The results show that the Sr/Ba and Mn/Fe values vary significantly in the marine sediments at different water depths in Quanzhou Bay, making them suitable as indicator elements in the marine and sea–land transitional sediments in the Quanzhou Bay coast, with the limit values of Sr/Ba<0.16 and Mn/Fe<0.23, respectively; there have been two transgression–regression processes since the MIS 3 in Quanzhou Bay. The first transgression occurred in the MIS3, corresponding to the regional "Fuzhou transgression," which peaked at about 35 ka B.P. The second transgression occurred in the Holocene, corresponding to the regional "Changle transgression," which peaked at about 7–4 ka B.P. The research results are significant for reconstructing the history of sedimentary environment changes in coastal zones, understanding sea–land interaction, and predicting future environmental changes.

Keywords

• quanzhou bay
• coastal zone
• mis 3
• transgression
• geochemical element ratio
• sedimentary environment