南沙海槽南部海区表层沉积物重金属元素含量及其影响因素

CONTAINED IN SURFACE SEDIMENTS AT SOUTH NAN-SHA TROUGH AND ADJACENT SEA AREA AND ITS AFFECTING FACTORS

南沙海槽南部海区表层沉积物重金属元素表现为亲陆性,丰度为:Ba>Sr>Zn>Ni>Zr>Pb>Cr>Cu>Co,浓集程度为Ba>Sr>Cr>Zr>Pb>Zn>Co>Ni>Cu,元素Cu-Zn,Cu-Ni,Cu-Ba及Ba-Zn呈明显正相关,Cu,Ni,Ba,Zn,Cr与水深变化关系较为密切。元素与CaCO3含量、氧化物含量、粒度组成的相关系数表明:（1）Pb,Co,Zr,既存在于陆源碎屑矿物晶格中,又以吸附状态被黏土吸附,还受碳酸盐沉积影响。（2）Sr,主要受生物碳酸盐沉积作用影响。（3）Cu,Zn,Ni,Cr,Ba,主要受黏土的吸附作用及铁锰氧化物的影响。

There are nine heavy metal elements such as Cu, Pb, Zn, Ni, Co, Cr, Sr, Ba, Zr, in Nansha Trough and adjacent sea area. The abundance order of heavy metal elements is Ba > Sr > Zn> Ni > Zr > Pb > Cr > Cu > Co, and the concentration order is Ba > Sr > Cr > Zr > Pb > Zn > Co > Ni > Cu. There are obviously positive correlations between internal elements just like Cu-Zn, Cu-Ni, Cu-Ba and Ba-Zn. The elements can be divided into three groups by the fair correlation between elements and CaCO3 ,oxides ,grain size. (1)Cu, Zn,Ni,Cr,Ba,which are absorpated on clay minerals and Fe^Mn oxide collids. (2) Sr,which affacted mainly by carbonate sediment. (3) Pb.Co.Zr, which affect by many factors.