镁铁-超镁铁岩与威尔逊旋回

威尔逊旋回的各个阶段都可以有镁铁-超镁铁岩的产出。在裂谷阶段有分异的小侵入体、层状侵入体以及碱性超镁铁岩体。洋盆阶段为蛇绿岩和可能的洋岛型辉长岩。在俯冲阶段生成阿拉斯加型和橄榄岩-闪长岩型杂岩,它们是岛弧和活动陆缘岩浆活动的一部分。与碰撞阶段有关的为橄榄岩-榴辉岩型岩体和造山榄榄岩,地幔核杂岩则产于碰撞后的后陆盆地或裂谷中,可能标志着从大陆内部向洋盆扩张阶段转变的开始。

THE MAFIC-ULTRAMAFIC ROCKS AND WILSON CYCLE

The mafic-ultramafic rocks could be formed in each stage of Wilson cycle. It is suggested that the formation of rift is related to hot spot in the mantle. There are distinct types of mafic-ultramafic rocks in rift stage, such as small differentiated intrusive complex, alkaline ultramafic rocks, and so on. There is ophiolite in oceanic basin stage. It is possible that the oceanic island gabbro also belongs to this stage. The Alaskan type and peridotite-diorite type complexes are related to subduction stage, and both are one of the parts of magmatism from island are or active continental margin. The peridotite-oclogite type complex is related to collision stage, but Yidun type and "mantle-core complex" may be formed in back-continent basin after collision, which marks the beginning of the transformation from continental stage to oceanic basin stage.