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祁连山地区出露有不同类型的镁铁－超镁铁岩，包括蛇绿岩、阿拉斯加型岩体、橄榄岩－闪长岩型岩体以及产于北祁连西部的一种特殊的镁铁－超镁铁岩组合。不同的镁铁－超镁铁岩形成于不同的构造环境：蛇绿岩代表洋壳的残片，阿拉斯加型岩体产于岛弧或活动陆缘环境，橄榄岩－闪长岩型岩体则是板块碰撞之后形成的。根据蛇绿岩与大致同时代的阿拉斯加型岩体产出的位置，推测在北祁连早古生代时存在向南的消减事件。
Different types of mafic-ultramafic rocks are exposed in the Qilian Mountains, including ophiolite, Alaska type rock, peridotite-diorite type rock mass and a special type of mafic-iron rock produced in western North Qilian - Ultramafic rock assemblage. Different mafic-ultramafic rocks are formed in different tectonic settings: the ophiolite represents the remnant of the oceanic crust, the Alaskan-type lithofacies occur in island arcs or active marginal environments, the peridotite-dioritic rock mass is The plate formed after the collision. According to the locations of the ophiolite and the roughly contemporary Alaskan-type rock mass, it is speculated that there is a southward decrease during the Early Paleozoic in the Qilian.