杨群慧, 李木军, 杨胜雄, 朱本铎, 季福武, 王虎, 周怀阳. 南海西南部表层沉积物粒度特征及输运趋势[J]. 海洋地质与第四纪地质, 2013, 33(6): 1-7. DOI: 10.3724/SP.J.1140.2013.06001
引用本文: 杨群慧, 李木军, 杨胜雄, 朱本铎, 季福武, 王虎, 周怀阳. 南海西南部表层沉积物粒度特征及输运趋势[J]. 海洋地质与第四纪地质, 2013, 33(6): 1-7. DOI: 10.3724/SP.J.1140.2013.06001
YANG Qunhui, LI Mujun, YANG Shengxiong, ZHU Benduo, JI Fuwu, WANG Hu, ZHOU Huaiyang. GRAIN SIZE DISTRIBUTION OF SURFACE SEDIMENTS IN THE SOUTHWESTERN SOUTH CHINA SEA AND TRANSPORT TREND ANALYSIS[J]. Marine Geology & Quaternary Geology, 2013, 33(6): 1-7. DOI: 10.3724/SP.J.1140.2013.06001
Citation: YANG Qunhui, LI Mujun, YANG Shengxiong, ZHU Benduo, JI Fuwu, WANG Hu, ZHOU Huaiyang. GRAIN SIZE DISTRIBUTION OF SURFACE SEDIMENTS IN THE SOUTHWESTERN SOUTH CHINA SEA AND TRANSPORT TREND ANALYSIS[J]. Marine Geology & Quaternary Geology, 2013, 33(6): 1-7. DOI: 10.3724/SP.J.1140.2013.06001

南海西南部表层沉积物粒度特征及输运趋势

GRAIN SIZE DISTRIBUTION OF SURFACE SEDIMENTS IN THE SOUTHWESTERN SOUTH CHINA SEA AND TRANSPORT TREND ANALYSIS

  • 摘要: 对南海西南部海域(3°56'~11°53'N、108°30'~113°47'E)95个表层沉积物样品进行粒度分析的结果表明,研究区主要分布黏土质粉砂和粉砂质黏土,仅在西南部浅水区分布少量砂和粉砂质砂。沉积物粒度参数的总体特征呈现出从浅水向深水粒径越细、分选越好、偏态值更负偏的趋势。用克里格方法对粒度参数进行插值,然后运用GAST程序对沉积物进行粒径趋势分析,结果表明地形对于研究区沉积物的输运起到控制作用。以广雅海台、南薇滩和永署北海台等海底高地形单元为界,以北,来自南海西部陆架的物质通过陆坡被输送进入南海西南海盆;以南,来自巽他陆架和加里曼丹岛的南部陆源物质,通过陆架坡折带被输送进入南薇西和北康陆坡盆地。阵发性的浊流等异常沉积事件会对沉积物粒径输运趋势分析结果产生显著影响,并且沉积物中<8 μm的细颗粒物质间的黏滞性对于沉积物粒径趋势分析结果也有影响,影响程度有待于今后进一步的研究。

     

    Abstract: Grain-size analysis is carried out for the 95 surface sediment samples from the southwestern part of the South China Sea(3°56'~11°53'N,108°30'~113°47'E), where clayey silt and silty clay dominate, with sand and silty sand only occurred in the most southwestern shallow part. There shows a trend of decreasing grain-size, increasing sorting and decreasing skewness from the shallow water to deeper water. The Kriging method was employed to insert data of the grain-size parameters (mean grain-size, sorting coefficient and skewness), and then the trend analysis was carried out for the interpolated data using the GSTA program. It is revealed that the seabed topography plays a key role in the sediment transport. There is a topographic high in the area including the Guang-ya submarine plateau, the Nan-wei-tan plateau, and the Yong-shu-bei submarine plateau. To the north of the high, sediments from the western South China Sea continental shelf are transported into the Southwest Basin of South China Sea; to the south of the boundary, however, materials from the Sunda shelf and the Kalimantan Island are transported into the Nan-wei-xi and Bei-kang slope basin passing by the shelf break. The episodic sedimentary events, such as the turbidity current, also have significant impacts on the grain-size distribution pattern. The aggregation of the components <8 μm should not be ignored. Further researches are required for details.

     

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