珠江三角洲经济区浅海地球化学异常分布特征及成因分析

摘要

This paper takes the shallow sea in the Pear river delta economic zone as the study area. We took a test for the seven heavy metal elements (As、Cd、Cr、Cu、Hg、Pb、Zn) in the sediment samples of surface , and delineated geochemical a-nomalies areas according to the environmental background values of the survey area. The result show that high-value anomalies of As、Cd、Cr、Pb and Zn appeared in Daya bay and in the northeast water of Macao. High value anomalies of Cu-.Pb,, Zn appeared in the bay near Shenzhen area where the Pearl river approaching the sea. The element of low anomalies occurred near to the Xunliao bay and Shuangyue Bay in Huizhou city, Guangdong province. The cause of high value anomaly may contribute to location, coastal landforms and the Bay, in addition to the economic activities such as port construction and operation. The depositions of pollutants exist in the bays where the coastal currents were blocked, so high value anomaly took place. The element of low anomalies occurred near to the Xunliao bay and Shuangyue bay in Huizhou city, Guangdong province may attribute to the lower industrial level in these areas.%以珠江三角洲经济区浅海为研究区,针对表层沉积物样品进行As、Cd、Cr等七种重金属元素地球化学指标分析测试,依据调查区环境背景值,圈定了地球化学异常区,发现:①在澳门东北部海域以及大亚湾海域存在As、Cd、Cr、Pb、Zn高值综合异常；②在珠江入海前靠近深圳的港湾处存在Cu、Pb、Zn高值综合异常；③在广东惠州巽寮湾、双月湾附近存在元素低值综合异常.造成元素高值综合异常的原因,除了港口建设及营运等经济活动有关以外,还与其海湾、海岸地貌、地理位置密切相关,在沿岸流流速变缓的港湾处、沿岸流受阻的地段,均易使河流中带入的污染物发生沉积,从而造成高值异常.在广东惠州巽寮湾、双月湾附近的低值异常主要归因于该地较低的工业水平.