关键词: 峨眉山玄武岩, 地球化学特征, 主量元素, 微量元素, 下地幔, 混染作用

Abstract: Based on the rock sampling analysis results,the geochemical characteristics of the main and trace elements of E'meishan basalt in Zhina Coalfield in Western Guizhou Province is discussed,and the genesis of the rock mass is also studied.The study results show that:①the contents variation range of SiO2 (from 30.98% to 57.19%) is large,the properties of the rock mass is belongs to basic volcanic lava,the TAS classification diagram show that the property of the rock mass is mainly for alkaline series,the rock mass is mainly enriched for the high field strength element (Nb,Zr,Hf,Ti) and Th,loss of Y,the volatility characteristics of Ba and Sr is significant,MgO content has significant negative correlation with Fe₂O₃ content and content ratio of CaO and Al₂O₃,and it has significant positive correlation with the contents of Ni and Cr;②the source of the rock mass may be the lower mantle,the rock mass is formed in the internal tensile structure environment,the isolated crystallization of the minerals (magnetite and olivine) is occurred,during the formation process of basalt,a certain mixed dyeing effect is suffered,the influence degree of sources area mixed dyeing effect to the formation of basalt is larger than the one of crustal mixed dyeing effect to the formation of basalt.

Key words: E′meishan basalt, Geochemical characteristics, Main element,Trace element, Lower mantle, Mixed dyeing effect