三亚近岸海域表层沉积物稀土元素地球化学特征及物源分析

Geochemical Characteristics and Provenance Analysisof Rare Earth Elements in Surface Sediments of Sanya Offshore Area

为充分了解三亚海岸带表层沉积物的物源状况,对三亚近岸海域331个站位表层沉积物的稀土元素进行了分析。结果表明:研究区表层沉积物稀土元素含量略低于南海大陆架和南海全区表层沉积物的平均水平,∑REE含量分布特征与沉积物粒径有很好的相关性,符合"元素粒度控制律";δEu值也与沉积物粒度有关,与Mz(Φ)为较显著的负相关关系。研究区稀土元素的特征参数呈明显的陆源特征,通过对本区稀土元素的特征参数及稀土元素球粒陨石、上陆壳(UCC)标准化配分模式综合判断,本区表层沉积物物源应主要以三亚近岸河流输入和沿岸侵蚀物为主,此外还有少量的自生生源沉积。

In order to fully understand the source of surface sediments in Sanya coastal zone, the rare earth elements of 331 surface sediment samples taken from the Sanya offshore area were analyzed. The results showed that the average content of rare earth elements in the surface sediments of the study area was slightly lower than the average level of the continental shelf and the entire surface sediments in the South China Sea. The distribution characteristics of ∑REE content have a good correlation with sediment particle size, which accords with "grain size control law of elements". The δEu values are also associated with sediment particle size, and has a significant negative correlation relationship with the Mz(Φ). The characteristic parameters of rare earth elements in the study area shows obvious characteristics of terrigenous, based on the comprehensive judgment of the characteristic parameters and the standardized partitioning model of chondrite and UCC of REE. The sources of the surface sediment in this area should be mainly river input and coastal erosion in Sanya, and there are also a few autogenic sediments.