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内蒙古达茂旗哈尔陶勒盖地区蛇绿岩的堆晶岩为橄榄岩+辉石岩+辉长岩组合,即为PPG型;通过岩石化学、地球化学研究,首次从辉长岩中识别出有玻安岩存在,为本区蛇绿岩的形成环境从岩类学方面提供依据;玄武岩具洋脊玄武岩特征,但俯冲带组分(Th等)富集;在混杂带内分布有泥盆纪岛弧型中-中酸性火山岩,整合于硅泥质岩之上。基于上述几个方面的分析,提出本区蛇绿岩的形成环境应为SSZ型,既形成于初始俯冲,在俯冲带之上(弧前)形成新的洋壳,并逐渐向岛弧演化。
The ophiolite in the Halkoteregaux region of Damaoqi, Inner Mongolia is composed of peridotite + pyroxene + gabbro, which is PPG type. For the first time, it is identified from gabbro by petrochemistry and geochemistry There is a boehite that provides evidence for the formation of ophiolites in the area from the perspective of petrography. Basalts are characterized by oceanic ridge basalts but enriched in subduction zones (Th, etc.); mud The basin-type arc-medium-acidic volcanic rocks are integrated with siliceous rocks. Based on the above analysis, it is suggested that the formation environment of ophiolite in this area should be of SSZ type, both formed in the initial subduction and formed a new oceanic crust above the subduction zone (before the arc) and gradually evolved into the island arc.