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对取自安达曼海东南部海域的95个表层沉积物样品进行了稀土元素(REE)地球化学研究,揭示了区内稀土元素分布特征及其指示的物质来源。结果表明研究区沉积物REE总量变化范围为31~228μg/g,平均值为117μg/g。沉积物REE球粒陨石配分模式呈现轻稀土元素相对富集而重稀土元素平坦,无明显Ce异常,呈现中等程度的Eu负异常等特征,表现出明显的陆源属性。REE的富集和分布受物质来源、沉积物类型、生物碳酸盐以及重矿物含量共同制约。根据沉积物REE特征参数将研究区分为4个物源区,各区沉积物稀土元素UCC标准化模式明显不同。物源判别分析显示,研究区西北部(Ⅰ区)沉积物主要来源于伊洛瓦底江陆源物质的输入;马来半岛西部浅海内陆架区(Ⅱ区)沉积物可能主要来自马来半岛沿岸水系输入的陆源物质以及现代近岸侵蚀;研究区北部(Ⅲ区)为残留沉积区,主要为全新世海侵形成的残留砂质沉积;研究区中部和南部大部分海域(Ⅳ区)为多源混合沉积区,主要为受印度季风驱动的西南季风流所搬运的伊洛瓦底江和马来半岛河流输入的陆源物质,该区沉积物受马来半岛入海物质影响更大。
Rare Earth Element (REE) geochemical studies of 95 surface sediment samples taken from the southeastern part of the Andaman Sea revealed the distribution characteristics of rare earth elements in the area and their indicated source of matter. The results showed that the total amount of REE in the sediments of the study area varied from 31 to 228 μg / g with an average of 117 μg / g. The distribution pattern of REE chondrites in sediments shows that the light rare earth elements are relatively enriched while the heavy rare earth elements are flat, with no obvious Ce anomaly, showing a moderate Eu negative anomaly and showing obvious terrigenous attributes. The enrichment and distribution of REEs are constrained by material sources, sediment types, biocarbons and heavy minerals. According to REE characteristics of sediments, the study area is divided into four provenance areas, and the UCC normalization patterns of the sediments in each area are obviously different. The provenance analysis shows that the sediments in the northwestern part of the study area mainly originate from the input of terrigenous materials in the Ayeyarwaddy River. The sediments in the shallow marine shelf area (Ⅱ area) in the west of the Malay Peninsula may come mainly from the sediment input Terrigenous matter and modern coastal erosion. The northern part of the study area (Ⅲ) is a residual sedimentary area, mainly consisting of residual sandy sediments formed by the Holocene transgression. In the central and southern part of the study area, most of the sea areas (Ⅳ) The area is dominated by terrestrial inputs from the Irrawaddy and Malay Peninsula transported by the southwesterly monsoon currents driven by the Indian monsoon. Sediments in this area are more affected by the sea-going substances in the Malay Peninsula.