The rotating structure, also known as the snowball structure, is a kind of metamorphic structure. The characteristic of the rotating structure is that the mineral inclusions in the phenocrysts are arranged in an "S" shape or spiral. It shows that the phenocrysts and the matrix minerals in them rotate under the influence of stress during the formation process. They are formed by crystallization in the same tectonic period.
版权申明 | 隐私权政策 | Copyright @2018 World encyclopedic knowledge