北黄海南部近岸海域表层沉积物稀土元素分布特征及影响因素

    Distribution characteristics and influencing factors of rare earth elements in surface sediments of the southern nearshore waters of the North Yellow Sea

    • 摘要: 根据北黄海南部近岸海域52个站位表层沉积物和7条主要入海河流沉积物样品粒度和稀土元素(REE)测试结果,分析了研究区粒度和稀土元素含量的平面分布特征,探讨了稀土元素分布的影响因素。结果表明,研究区表层沉积物大致呈由近岸向海沉积物粒度变细的特征。研究区稀土元素含量普遍高于长江、黄河和中国黄土等地区,总体呈轻稀土富集、重稀土亏损的特点。稀土元素的含量及分布特征受粒度特征、矿物成分、风化作用及物质来源等多种因素影响,其中矿物成分对研究区稀土元素的影响较为显著,稀土元素的高含量可能与陆源碎屑矿物(长石类矿物、含钛矿物等)的富集有关;粒度的影响主要反映在重稀土元素更容易富集在细粒组分含量较高的沉积物中;风化对稀土元素的影响主要是通过多种物源混合完成;研究区稀土元素所指示的物质来源以黄河源沉积物为主。

       

      Abstract: Based on the results of grain size and rare earth element (REE) testing of surface sediments from 52 stations in the nearshore waters of the southern part of the North Yellow Sea and sediment samples from seven major rivers, the planar distribution characteristics of grain size and REE content in the study area were analyzed, and the factors influencing the distribution of REEs were discussed. The results show that the surface sediments in the study area are roughly characterized by finer grain size from nearshore to sea sediments. The content of rare earth elements in the study area is generally higher than that in the Yangtze River, Yellow River and China Loess areas, and is generally characterized by the enrichment of light rare earths and loss of heavy rare earths. The content and distribution of rare earth elements are affected by various factors such as grain size, mineral composition, weathering and material source, among which the mineral composition has a more significant influence on the rare earth elements in the study area, and the high content of rare earth elements may be related to the enrichment of land-sourced detrital minerals (feldspar minerals, titanium-containing minerals, etc.); the influence of the grain size is reflected in the fact that the heavy rare earth elements are more likely to be enriched in the sediments with high content of fine-grained components; the effect of weathering on the sediment is also reflected in the fact that the heavy rare earth elements are more easily enriched in the sediments with high content of fine-grained components; the effect of weathering on the sediment is more significant. The effect of weathering on rare earth elements is mainly accomplished through the mixing of multiple sources; the source of rare earth elements in the study area is dominated by the Yellow River source sediments.

       

    /

    返回文章
    返回