广西十万大山盆地盖层地质特征及形成环境探讨

摘要

The classification of cover in shiwandashan basin is according to the third act of the indosinian movement -longhua movement caused the formation of unconformity surface as the lines between, including on the upper triassic, jurassic, cretaceous and tertiary continental and the marine sediments in the transitional phase on lower part.Phoenix mountain profile exposed Jurassic stratum, from down to up in turn baixing group and the nadang group.Analysis of trace-rare earth elements parameters of profile samples, Th -Sc -Zr/10 discrimination diagram indicating the structural setting of clastic rock is continental island arc environment.δEu, δCe and V/( V +Ni ) ratio show that the sedimentary environment is given priority with anaerobic weak reduction environment.%十万大山盆地盖层划分是根据印支运动第三幕－龙华运动造成的中三叠系不整合面为界线划分的，包括上三叠系、侏罗系、白垩系以及第三系的陆相和下部一部分海陆过渡相的沉积物。凤凰山剖面出露侏罗系地层，从下往上依次为百姓组和那荡组。对剖面样品进行微量稀土元素参数分析， Th－Sc－Zr／10判别图解指示碎屑岩形成的构造背景为大陆岛弧环境。δEu、δCe及V／（ V＋Ni）比值表明当时沉积环境以厌氧的弱还原环境为主。