Provenance analysis of surface sediments in the Holocene mud area of the southern coastal waters off Shandong Peninsula,China

摘要

The sedimentary record of mud areas is an important carrier of information on the Holocene evolution of marine environments. Based on fine interpretations of the shallow stratigraphic section data, a small mud deposit area has been found in the southern coastal waters off Shandong Peninsula. This mud area is mainly distributed in coastal waters north of Laoshantou to the vicinity of Rushan Estuary. Overall, it is parallel to the coastline and spreads in a banded pattern, gradually thinning from offshore to the sea. The isopach map of depth distribution is parallel with the shoreline, and the depocenter lies in coastal waters of the Aoshan Bay where the maximum thickness is up to 22.5 m. Accelerator mass spectrometry(AMS) ^(14)C dating shows that the mud area was formed in the Holocene. The test data of surface sediments from themud area, including particle size, mineral characteristics, and rare earth element contents, are used in comparisons with the composition of materials from the major surrounding medium and small rivers flowing into the sea and the Huanghe(Yellow) River. In this paper, the sedimentary characteristics and provenance of the mud deposit area are discussed. The results show that the formation of this mud area resulted from the joint action of the Huanghe River and surrounding rivers flowing into the sea.