莱州浅滩表层沉积物元素地球化学特征及物源识别

使用电感耦合等离子体质谱仪对采自莱州浅滩表层沉积物悬浮组分进行研究, 从地球化学角度分析了6 种常量元素质量分数、24 种微量元素质量比特征及它们与黄河细粒沉积物的联系。研究表明:莱州浅滩所取的7 个样品东西两侧略有差异, 元素质量分数的变异系数较小, 样品间变化不明显, 同源性和整体性显著。同黄河沉积物相比, 莱州浅滩细粒泥沙Al, Fe, Ca, K, Mg 和部分金属元素Cu, Zn质量分数略高, 大多数微量元素质量比略低, 两者大多数元素的判别系数绝对值较低, 标准偏差比值也较小, 经过Al 标准化处理后, 各元素对比值变化趋势较一致, 表现出较强的相似性。黄河细颗粒沉积物可以通过余流、环流扩散迁移至整个渤海, 而莱州浅滩所处地理位置及水文环境为黄河悬浮泥沙提供了良好的沉积条件, 黄河泥沙的沉积使浅滩细粒沉积物表现出了黄河沉积物的元素特征, 而两者细微差异可能与附近河流输沙、元素迁移方式及人类活动影响有关。通过莱州浅滩表层沉积物与黄河样各元素地球化学特征对比分析可以为探索黄河的入海悬浮组分在海域中的混合及扩散提供参考。

Elemental geochemistry and provenance of surface sediments from the Laizhou Shoal

Surface sediments collected in the Laizhou Shoal were analyzed by inductively coupled plasma-mass spectrometer. Chemical analysis was performed to investigate the characteristics of elemental geochemistry of the Laizhou Shoal. The content of each element was normalized by that of Al. The composition of the study area was influenced by regional dynamic conditions. The elemental contents of samples from the western area were slightly higher than samples from the eastern area. However, the tiny fluctuations of all samples reflected they had the same provenance. Compared with the Yellow River, the contents of most major elements and some metal elements, such as Al, Fe, Ca, Mg, Cu and Zn, in the Laizhou Shoal were slightly higher, while the contents of most trace elements were slightly lower. The characteristics of the contents of six major elements and 24 trace elements indicate the sedimentary geochemical composition of the Laizhou Shoal is very similar to the Yellow River, indicating the surface sediments of the Laizhou Shoal partly come from the Yellow River. The differences of elemental characteristics between the Laizhou Shoal and the Yellow River may result form geological background, dynamic conditions, element migration and human activities.