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在苏鲁超高压榴辉岩中,石榴石和绿辉石包含两类长英质多晶包裹体.第一类由钠长石、石英和少量钾长石组成;第二类主要由钾长石和石英组成,不含钠长石.在超高压基性榴辉岩中,长英质多晶包裹体的存在进一步表明:在快速折返早期,深俯冲大陆地壳物质发生过明显的云母(钠云母或多硅白云母)部分熔融作用,形成含水的纯花岗质Na-K-Al-Si熔体.这些熔体被重结晶的石榴石或绿辉石捕获,发生脱水结晶作用,形成含长石和石英的多晶聚合体.长英质熔体的存在不仅导致流体中活动元素,如大离子亲石元素(LILE),而且是导致流体中不活动元素,如高场强元素(HFSE)迁移的重要机制.同时深俯冲大陆岩片的部分熔融作用有效地改变了岩石的物理性质,是强化深俯冲岩石快速折返的重要因素之一.
In the Sulu ultrahigh-pressure eclogite, garnet and omphacite are composed of two types of feldspathic polycrystalline inclusions, the first of which consists of albite, quartz and a small amount of potassium feldspar. The second is mainly composed of potash feldspar and quartz , No sodium feldspar in the EHP eclogite, the presence of feldspathic polycrystalline inclusions further shows that: in the early rapid reentry, the deep subduction of the continental crust material had obvious mica (mica or polysilicon Muscovite) partially melted to form a water-containing pure granitic Na-K-Al-Si melt, which is captured by recrystallized garnet or omphacite and undergoes dehydrocrystallization to form feldspar- and quartz-bearing Polymorphic polymers.The presence of felsic melt not only leads to active elements in the fluid, such as LILE but also to important mechanisms leading to the migration of inactive elements in fluids, such as high-field-strength elements (HFSE) At the same time, the partial melting of deeply subducted continental tablets effectively changed the physical properties of the rocks, which is one of the important factors for strengthening the rapid reef - turning of deep - subducted rocks.