北祁连山是我国海相火山岩发育良好的地区之一。在该区,早古生代喷出的大量的各类火山物质,组成了一套沉积巨厚、分布广泛的浅变质绿色火山岩系。这套火山岩系形成于北祁连加里东地槽回返前的长期坳陷阶段,喷发活动受地壳软弱地带的深断裂控制,因此各类火山岩呈线(带)状分布,具有水下火山活动的典型特征。近几年来,对本区古海相火山作 North Qilian Mountains is one of the well-developed areas of marine volcanic rocks in China. In this area, a large amount of various volcanic materials ejected in the Early Paleozoic formed a set of super-metamorphic green volcanic rocks of extensive deposition and extensive distribution. This volcanic series formed in the long-term depression before returning to the Gallstone trench in the North Qilian. The eruption activity was controlled by deep faults in the soft crust of the crust. Therefore, the volcanic rocks are distributed in a line (belt) pattern with underwater volcanic activities Typical characteristics. In recent years, the ancient volcanic sea in this area for