Sedimentary architecture of the Holocene mud deposit off the southern Shandong Peninsula in the Yellow Sea

As a key sedimentary body connecting the north and South Yellow Sea, the subaqueous clinoform off Shandong Peninsula plays an important role in the sedimentary system of China seas, and it is also a studied example in the study among the major “source to sink” systems. Based on AMS 14C dating, sediment grain size, major and trace element contents from core WH-05 located at the edge of the clinoform, we discuss changes in the deposition rate, analyze sediment provenance and controlling factors, and reveal the environmental evolution of the source area since the Holocene. Results from core WH-05 show that marine sedimentation began at about 8.5 ka B.P. The deposition rate decreased from the initial 28.37 m/ka to 0.52 m/ka. Sediment provenance suggests that the Huanghe river sediments have been the main source for the study area since the Holocene. The As/Al, V/Sc indicators show that the environmental oxidation environment was gradually weakened and then increased slightly starting from 7.0 ka B.P. The change in redox is consistent with the change in sea level, the deposition rate, and depositional depth.

Download Full-text

A paleoenvironmental reconstruction of the last 15 000 cal yr BP via Yellow Sea sediments using biomarkers and isotopic composition of organic matter

Climate of the Past Discussions ◽

10.5194/cpd-10-1527-2014 ◽

2014 ◽

Vol 10 (2) ◽

pp. 1527-1565 ◽

Cited By ~ 1

Author(s):

A. O. Badejo ◽

B.-H. Choi ◽

H.-G. Cho ◽

H.-I. Yi ◽

K.-H. Shin

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Yellow Sea ◽

Climatic Conditions ◽

Plant Distribution ◽

The Yellow Sea ◽

Paleoenvironmental Reconstruction ◽

Glacial Period ◽

The Holocene ◽

Glacial Periods

Abstract. This study is the first reconstruction of the paleoenvironment and paleovegetation during the Holocene (interglacial) and glacial periods of the Yellow Sea. We report the carbon isotopic and biomarker (n-alkane and alkenone) compositions of organic matter from Yellow Sea sediments since the glacial period. Our findings show that the variability of the East Asian Monsoon (EAM) affected the sedimentary profile of total organic carbon (TOC), the stable isotopes of bulk organic carbon (δ13Corg), the atomic ratio of carbon and nitrogen (C/N ratio), and biomarker content. The sedimentary δ13Corg profile along the core exhibited more negative δ13Corg values under cold/dry climatic conditions (Younger and Oldest Dryas). The carbon preference index (CPI), the pristane to phytane ratio (Pr/Ph) and the pristane to n-C17 ratio (Pr/n-C17) were used to determine the early stages of diagenesis along the sediment core. Two climatic conditions were distinguished (warm/humid and cold/dry) based on an n-alkane proxy, and the observed changes in δ13C of individual n-alkane (δ13CALK) between the Holocene and glacial periods were attributed to changes in plant distribution/type. Clear differences were not found in the calculated alkenone sea surface temperature (SST) between those of the Holocene and glacial periods. This anomaly during the glacial period might be attributed to the seasonal water mass distribution in the Yellow Sea or a seasonal shift in the timing of maximum alkenone production as well as the Bølling/Allerød interstadial.

Download Full-text