冲绳海槽中段末次冰消期以来的元素地层  

The elementary stratigraphy of the middle Okinawa Trough since the last deglaciation

作　　者：刘焱光[1] 孟宪伟[1] 李铁刚[2] 吴世迎[1] 王湘芹[1] 辛春英[1] 任红[1] 

机构地区：[1]国家海洋局第一海洋研究所 [2]中国科学院海洋研究所,山东青岛266071

出　　处：《海洋学报》2003年第4期50-58,共9页

基　　金：国家自然科学重点基金(49736210);国家自然科学基金(49706068;49873015)

摘　　要：在对冲绳海槽中段180号岩心进行高分辨率取样的基础上,测定了沉积物中的23个地球化学指标,通过对各元素与Al_2O_3含量的比值在岩心中的垂向变化规律的分析,结合氧同位素、黏土矿物、粒度、AMS^(14)C测年和R型因子分析方法,可将岩心从上至下划分为5层:第1,3,5层具有相似的元素组合特征,第2,4层为明显的异常变化层位,将元素的地球化学行为、元素组合与物质来源联系起来,并与碎屑矿物、古生物资料对比,探讨岩心中元素组合垂向变化的制约因素,据此讨论了冲绳海槽中段末次冰消期以来陆源、火山源及生物源物质的分布规律。结果表明,冲绳海槽中段末次冰消期以来的沉积物来源以陆源物质为主,但在局部层位可因生源组分和火山源组分的强烈影响而发生实质性的变化。A gravity Core 180 was collected from the middle Okinawa Trough. The 305 cm long core was sampled at the interval of 5 cm. Twenty-three geochemical indexes of these samples were obtained on the basis of different analytical methods. According to the explanations for vertical changing regularity of the ratio of elements to Al2O3, δ18O records, clay mineral composition, grain size, combined with AMS14C determination and factor analysis, Core 180 can be divided into five sections. The similar elementary combination characteristics exist in Sections 1, 3 and 5, and different characteristics exist in Sections 2 and 4. Compared with detrital mineral and paleobiological analysis data, the distribution of the sedimentary compositions originated from continent, volcanic and biogenetic material has been discussed by means of correlation analysis of elementary geochemical behavior, elementary combination and sedimentary sources. The results show that the main sedimentary sources of the middle Okinawa Trough are terrigenous materials. But some essential changes maybe occur in the special layers due to the intensive influence of volcanic and biogenetic sediments.

关 键 词：冲绳海槽 元素地层学 海洋沉积学 末次冰消期 海洋地球化学 

分 类 号：P736.4[天文地球—海洋地质] P736.223[天文地球—海洋科学]