Volcanic rocks in Chabaoma formation should be belonged to high pressure type trachyt,formed by the magma beneath thickened crust, the exact extrusive era could be mid-late period of Miocene.

• 查保马组火山岩应属于在陆壳增厚的背景下,加厚陆壳底部产生的粗面岩岩浆上涌形成的粗面岩,时代应为中新世中晚期。