The extrusive rock unit includes basalt, andesite, boninite and albitite as well as breccia and tuff.

喷元不仅仅由玄武组成，还包括安山、玻安、钠长以及角砾、凝灰等。

Volcanicity was violent during the Early Carboniferous in Santanghu region.The volcanic rocks consist of basalts,andesites and dacite liparite,with andesites playing the main part.

三塘湖地区早石炭世火山活，发育以安山类为主的玄武、安山、英安流纹的石组合。