中全新世以来南海琼东南近岸泥质区物质来源

发布时间：2018-04-13 18:37

本文选题：南海 + 陆架　；参考：《海洋学报》2016年07期

【摘要】：对位于南海琼东南近岸泥质区的X2站柱状沉积物进行了粒度、Sr-Nd同位素、常量元素(Al_2O_3、TFe_2O_3、K_2O、MgO、Na_2O、TiO_2、CaO、P_2O_5、MnO)和AMS14 C年代分析,探讨了中全新世以来该沉积区的物质来源。结果表明,X2站沉积物可划分为上(A2段,120~0cm,4.0~0ka BP)、下(A1段,240~120cm,7.6~4.0ka BP)两个沉积地层单元,A2段较A1段沉积物平均粒径变粗,已测的9种常量元素含量减少。~(87)Sr/~(86)Sr与εNd除异常点外,总体变化幅度不大。X2站沉积物主要来源于海南岛和台湾,珠江贡献较小,其中A1段沉积物主要是海南岛和台湾岛来源物质的混合,A2段沉积物主要来源于海南岛,其次珠江物质可能也有影响。据X2站研究结果初步表明,世界级大河(如珠江)对南海北部陆架区(特别是琼东南近岸泥质区)的贡献以前可能被高估,而山溪型河流(如台湾岛、海南岛等河流)的贡献却可能被低估,日后研究中应该重视小型河流对陆架区的物质贡献。
[Abstract]:The columnar sediments of X2 station near the southeastern coast of the South China Sea have been analyzed by means of the grain-size Sr-Nd isotopes and the major element Al2O2O3TFe2O3 / TFe2O3K _ 2O _ 3 / MgO _ 2O _ 2CaO _ 2O _ 2CaO _ 2O _ 5mn _ O) and AMS14 C chronology. The source of material in this sedimentary area since the Middle Holocene has been discussed.The results show that the sediments from the X _ 2 station can be divided into two sections, I. e., the upper A _ 2 member (120 cm ~ (0)) ~ (4.0) ka BPU, and the lower _ (A _ 1) _ (2) sedimentary stratigraphic unit, the average grain size of the A _ 2 member is thicker than that of the A _ (1) member, and the measured contents of 9 kinds of elements are reduced by .87Srr ~ (-) ~ (86) C ~ (+) Sr and 蔚 ND, except for the anomalous point.The sediment of station X2 is mainly from Hainan Island and Taiwan, and the contribution of Pearl River is relatively small. The sediment of A1 member is mainly from Hainan Island and Taiwan Island, and the mixed A2 sediment of Hainan Island and Taiwan Island mainly comes from Hainan Island.Secondly, the Pearl River material may also have an impact.Preliminary results from the X2 station show that the contribution of world-class rivers (such as the Pearl River) to the continental shelf in the northern part of the South China Sea (especially the nearshore muddy area in southeastern Hainan) may have been overestimated before, while mountain stream rivers (such as Taiwan Island) may have been overestimated.The contribution of rivers such as Hainan Island may be underestimated, and the material contribution of small rivers to the continental shelf should be emphasized in future studies.
【作者单位】：中国石油大学(华东)地球科学与技术学院;国家深海基地管理中心;国土资源部海洋油气资源和环境地质重点实验室;中国科学院海洋研究所海洋地质与环境重点实验室;西安科技大学地质与环境学院;
【基金】：国家自然科学基金(41430965,41106040,41576058) 国家科技重大专项(2016ZX05047-003,2011ZX05009-002) 中央高校基本科研业务费专项资金(12CX02003A) 青岛市基础研究计划项目(13-1-4-197-jch)
【分类号】：P736.2

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