企鹅山群火山岩的地球化学特征和构造环境

Geochemical characteristics and tectonic environment of Qieshan Group volcanic rock

目的．研究东天山地区企鹅山群火山岩形成的构造环境。方法采用元素地球化学方法。结果东天山地区广泛分布的石炭纪企鹅山群火山岩为拉斑系列火山岩，基性火山岩稀土分配型式表现为LREE富集型，Hf/Th值为3．04～8．28，Ce／Nb值为6．09～7．4；在微量元素构造环境判别图上，基性熔岩均位于板内玄武岩区。结论东天山企鹅山群火山岩形成于大陆裂谷环境。

Aim To study tectonic environment of Qieshan Group volcanic rock in the East Tianshan. Methods Aralyge the geochemical characteristics of Qieshan Group volcanic rock in the East Tianfshan. Results Carboniferous Qieshan Group volcanic rock distributing abroad is tholeiitc-series, chondrite-normalized REE patterns of the basic volcanic rock show enriching LREE, Hf/Th is 3.04 - 8.28, Ce/Nb is 6.09 - 7.4, the basic lava locates within plate basalts on the trace element scheme. Conclusion The Qieshan Group volcanic rock formed in the continental-rift environment.