茅山东部地区第三纪两期玄武岩综合地质特征

茅山东部地区第三纪两期玄武岩 ,在岩石地层上命名为凉帽顶火山岩锥、方山火山岩锥 ,分别隶属于渐新世三垛组和中—上新世雨花台组 ,相当于两个火山旋回 ,在岩石学、岩石化学、地球化学上有一定的演化规律。两期玄武岩均属钠质碱性玄武岩系列、B类岩浆 ,原始岩浆来源于深部上地幔

Comprehensive Geological Characters of Two-types Tertiary Basalt in the Eastern Maoshan of Jiangsu Province

Two types Tertiary basalt in the eastern Maoshan Mountain is named as Liangmaoding and Fangshan volcanic cones according to the lithostratigraphy. In accordance with the two volcanic cycles, they can be divided into Oligocene Shanduo Fm. and Upper Middle Pliocene Yuhuatai Fm. and there is a special evolutionary trend. Two types basalt belongs to the agpaitic alkali basalt and B type magma. The accumulation and elevation of high temperature agpaitic alkali basalt magma, caused by inherited activities of NNE strike faulted zone in the eastern Maoshan, have produced two large scales of eruption, forming a NNE strike faulted magmatic activity zone. The primary magma belongs to B type and its depth is over 35km in terms of study.