论文部分内容阅读
对扬子地台南缘元古代浊积岩的常量元素和微量元素地球化学研究表明 ,源区遭受了中等程度的风化作用影响 ,这种影响记录在碱金属和碱土金属元素的丰度与分布型式、蚀变化学指数 ( CIA)以及 Th/U比值等方面。稀土元素的组成和配分型式、Th/Sc和 La/Sc比值以及其他常量和微量元素之间的关系表明 ,沉积岩不具备成熟的再旋回沉积物的特征 ,其源岩主要为由酸性岩浆岩等长英质组分构成的古老上地壳 ,源岩曾受到了显著的壳内分异作用的影响。中元古界冷家溪群地层的源岩较新元古界板溪群含有较高的 Co,Cr,Ni,Sc,V等基性组分 ,且基性的铁镁质成分主要反映在粘土级组分的沉积记录中。
The study on the elemental and trace element geochemistry of the Proterozoic turbidites in the southern margin of the Yangtze platform shows that the source area is affected by moderate weathering. This effect is recorded in the abundance and distribution patterns of alkali metals and alkaline earth elements, Alteration chemistry index (CIA) and Th / U ratio and so on. The composition and composition of REEs, Th / Sc and La / Sc ratios, and the relationship between other constants and trace elements show that sedimentary rocks do not have the characteristics of mature re-cycled sediments, and their source rocks mainly consist of acidic magmatic rocks The ancient upper crust, source rocks, formed by the long quartzites, have been subjected to significant intracavity differentiation. The source rocks of the Lengjiaxi Group in the Proterozoic contain higher basic elements such as Co, Cr, Ni, Sc and V than the Neoproterozoic Banxi Group, and the basic Fe-Mg components are mainly reflected in the Clay-component deposition records.