Chronology of coastal aeolian deposition and its paleoenvironmental implications on the Liuao Peninsula of South China

Abstract

Coastal dunes are a common geomorphic type in sandy coastal zones. They are a record of the coupled evolutionary processes of the wind and ocean waves. Many coastal dune fields have developed on the east coast of Fujian China and now occur as widespread typical coastal aeolian sand landforms on the Liuao Peninsula, Gulei Peninsula and Dongshan Island, but it is difficult to evaluate the dynamic geomorphologic process of sandy coast due to the lack of systematic and accurate chronological data. In this study, we selected the Hutoushan (HTS) aeolian dune on the Liuao Peninsula as the research object. Optical dating and grain-size analysis were applied to sand samples from the aeolian sequence of a profile of the HTS dune. The results show that the ages of seven samples of this profile were in the range of 37.8–0.19 ka from 4.0 to 0.2 m deep. These correspond to the Marine Isotope Stage 3 (MIS3), abrupt climatic change events of 4.2 and 1.1 ka and the Little Ice Age (LIA), respectively. These samples displayed evidence of a longer-term climate trend in this area. The period of formation of this coastal aeolian dune corresponds to a cold and arid climate associated with the East Asia Winter Monsoon (EAWM). Periods of dune fixation and rubification are evidence of a hot and humid climate. Mobilization and stabilization of the aeolian dune is an important characteristic of the coastal evolution in South China since the late Pleistocene.