东海南部内陆架泥质区S05-2孔沉积物4870a BP以来的沉积学记录及其对物源与季风演化指示*

以东海内陆架S05-2孔沉积物为研究对象, 进行了加速质谱仪(AMS)¹⁴C年龄测定、粒度测试、粘土矿物及地球化学元素含量分析。研究表明: 东海内陆架泥质区南部水动力环境强, 沉积物主要以粉砂为主; 4870a BP以来研究区的物源以台湾岛河流物质为主, 长江和黄河物质在不同阶段存在间歇物质作用。通过元素比值、敏感粒级、粘土矿物含量比等季风气候指标, 指示了研究区的季风气候自4870a BP以来存在稳定、增强、减弱、再次增强的4个季风气候强度变化期。

Sedimentary record from Core S05-2 and its implication of provenance and monsoon evolution in a muddy area of the inner shelf of the Southern East China Sea since 4870 a BP*

For better understanding of the sedimentary process and climate evolution in the East Asian continental shelves, we investigated the core sediments collected from the inner shelf of the East China Sea in terms of aspects of Accelerator Mass Spectrometry (AMS) radiocarbon dating, grain-size, clay minerals, and geochemical element concentrations. The studied sediments were deposited in the last 4870 a BP according to radiocarbon dating. The results show that silt is the dominant component of the sediments from the mud area of the East China Sea. The rivers on Taiwan Island contributed to the deposits in the studied area dominantly, whilst materials from the Yellow River and Yangtze River occurred episodically in the last 4870 a BP. The East Asian winter monsoon could be indicated by element ratio, sensitive grain-size and clay mineral content ratio. It suggests that the East Asian winter monsoon was stable, strengthening, weakening, and re-strengthening from 4870 a BP onward.