川东南-黔中及其周边地区下组合烃源岩元素地球化学特征及沉积环境意义

Element geochemical characteristics of the lower assemblage hydrocarbon source rocks in southeast Sichuan-central Guizhou(Chuandongnan-Qianzhong) region and its periphery areas and their implications to sedimentary environments

笔者采用ICP-MS测试分析技术,对川东南-黔中及其周边地区震旦-志留纪地层28件样品进行了B、V、Ni、Sr、Ba、Th、U等指示沉积环境的敏感微量元素做了系统测试分析,采用GB/T14506.28-93硅酸盐岩石化学分析方法和X射线荧光光谱法测定主要元素和微量元素含量,并探讨了Sr/Ba、V/Ni、V/(V+Ni)、Sr/Ca、Ca/Mg、Th/U比值与沉积环境的对应关系。分析结果表明,本区下组合沉积环境主要为半深海、深海及浅海滞流环境。元素空间分布的差异性反映了沉积环境的区域性变化。

This paper deals with the contents of such elements as B, V, Ni, Sr, Ba, Th and U by using the ICPMS （Inductively Coupled Plasma-Ms Spectrometer） technique for 28 samples collected from Sinian-Silurian strata in Chuandongnan-Qianzhong region and its periphery areas. The contents of major and trace dements were determined by means of GB/T14506.28-93 and X-Ray Fluorescence Spectrometry. The corresponding relationships between the Sr/Ba, V/Ni, V/（V ＋Ni）, St/Ca, Ca/Mg and Th/U values and the sedimentary environments were studied. The results show that the main sedimentary environments are bathyal, deep-sea or shallow sea stagnant environments. The difference in spatial distribution of dements reflects regional variation of the sedimentary environment.