【摘要】 通过对比研究了冲绳海槽南部、中部、北部岩心沉积物的稀土元素(REEs)组成和分异特征,揭示了冲绳海槽不同区域的物源差异。由于火山物质和周围河流携带的陆源物质贡献程度不同,各岩心沉积物REE组成存在显著差异。∑REE、∑LREE具由南至北递减的趋势,北部具相对更高的∑HREE,南部次之。LREEs与HREEs间的分馏程度,LREEs、HREEs内部分馏程度均由南至北依次减小。从粒度、微量元素和稀土特征参数的垂向变化来看,岩心S3物源相对单一,沉积环境随时间变化较小,主要受长江和台湾河流沉积物控制。岩心S10、S9沉积物来源更为复杂多样(特别是S9),沉积环境在时间尺度上发生了较大的变迁。岩心S10层位1主要受黄河和长江沉积物控制,层位2具黄河沉积物和火山物质混合的特征,岩心S9层位1是黄河沉积物和火山物质混合的结果,层位2主要受黄河沉积物控制。更多还原

【Abstract】 Multiple provenances are confirmed in the Okinawa Trough by a comparative study of the composition and fractionation of rare earth elements(REEs)in the sediment cores from southern,middle,and northern parts of the Trough.Distinctive differences in REEs compositions are discovered in different cores due to the different contribution of terrigenous detrital sediments from surrounding rivers and volcanic sources.The values of∑REE and ∑LREE decrease from south to north,whereas∑HREE values are relatively high in the north and followed by the south as the next.The fractionation degree between LREEs and HREEs,and the internal fractionation degrees of LREEs and HREEs decrease from south to north.The vertical variations in grain size,trace elements and REE characteristic parameters suggest that the sediment provenance of Core S3 was rather simple and the depositional environment was relatively stable.It is mainly controlled by terrigenous materials from the Yangtze River and Taiwan rivers.However,the sediment provenance of Core S10 and Core S9 are quite complicated,especially in the core of S9.Provenance changes remarkably with time.Layer 1 of Core S10 principally came from both the Yangtze River and Yellow River,while the Layer 2 has the mixed characteristics of volcanic materials and Yellow River sediments;The Layer 1 of Core S9 is the mixed deposits of volcanic materials and the Yellow River sediments,whereas the Layer 2 is mainly derived from the terrigenous particulate matters from the Yellow River.更多还原