摘要
中太平洋海盆不同类型的深海沉积物中稀土元素的含量、比值和分布模式,有明显的差异,造成这种差异的主要原因是沉积物的组分变化。稀土元素在沉积物中的主要赋存状态有两种:(1)存在于矿物的结晶格架中;(2)以吸附状态存在,其吸附量大小与组分有关,沸石的吸附量最高,其次为粘土,有孔虫壳最低。
Deep-sea sediments in the central Pacific Ocean Basin are classified as five types: zeolite clay, deep-sea clay, siliceous clay, calcareous clay and calcareous ooze. The concentrations of REE in the different types of sediments are significantly variable, ranging from 57 to 805ppm. REEs in the zeolite clay are most abundant (689-805 ppm). The lowest value is noticed for the calcareous ooze (57-86 ppm). The concentrations of REE in these sediments vary in descending order of zeolite clay→deep sea clay→calcareous clay→calcareous ooze. It is obvious that REE concentrations are positively correlated with the contents of clay and zeolite minerals in these sediments, but negatively with the contents of organic sheik in these sediments.The REE distribution patterns in all the sediments are characterized by a remarkable negative Ce anomaly.Studies have shown that two existing forms of REE are distinguished: existing in the crystal lattice of Alsilicate minerals and being adsorbed on clay and zeolite minerals.
出处
《地球化学》
CAS
CSCD
北大核心
1990年第4期340-348,共9页
Geochimica
