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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。
The grain size, Sr-Nd isotopes, major elements (Al_2O_3, TFe_2O_3, K_2O, MgO, Na_2O, TiO_2, CaO, P_2O_5, MnO) and AMS14C dating of the sediments in station X2 of the southeastern Qiong- Analyzed and discussed the material source of this sedimentary area since the Middle Holocene. The results show that the sediments in station X2 can be divided into two sedimentary unit units (A2, 120 ~ 0cm, 4.0 ~ 0ka BP) and the lower (A1, 240 ~ 120cm, 7.6 ~ 4.0ka BP) The mean grain size of the sediments became thicker, and the content of the nine kinds of constant elements decreased. In addition to the abnormal spots, ~ (87) Sr / ~ (86) Sr and εNd did not show much change. The sediments of station X2 are mainly from Hainan Island and Taiwan, with little contribution from Pearl River. Sediments in section A1 are mainly from the source materials of Hainan Island and Taiwan Island. Sediments in A2 section mainly come from Hainan Island. . According to the results of station X2, preliminary results indicate that the contribution of world-class rivers such as the Pearl River to the northern Shelf of the South China Sea (especially the Qiongdongnan Coastal Argillaceous area) may have been overestimated. However, mountain streams such as Taiwan Island and Hainan Island and other rivers) may be underestimated, and future studies should pay attention to the material contribution of small rivers to the shelf area.