海州—大悟混合岩穹窿地质及成矿作用

文章是在研究海州－大悟含磷岩系及其磷矿底板岩石中不同类型混合岩的岩石学、地球化学的基础上，探讨了变质－深熔过程中稀土元素的活动性状。混合岩穹窿由变沉积岩、混合岩及混合花岗片麻岩组成。变沉积岩、混合岩及混合花岗片麻岩在空间上的密切共生关系，揭示了沉积物经历了变质分异、混合岩化和部分熔融作用改造成花岗质岩石的过程。穹窿具有明显的分带性，从穹窿外向中心，由变质岩带、混合岩带向混合花岗片麻岩带变化，表明了变质反应顺序及混合花岗岩化交代的关系。在变质、混合岩化及部分熔融作用形成混合岩穹窿过程中，磷质发生了运移，在穹窿变质岩与混合岩接触带发生了交代结晶与重结晶作用。在穹窿变质岩带，揉流褶皱成矿作用十分明显

THE GEOLOGY AND METALLOGENESIS OF THE MIGMATITE DOME IN HAIZHOU-DAWU

Based on the petrological and geochemical studies of different types of migmatites of the phosphatic rock formation and its bottom bed, this paper discusses the mobility of REE during metamorphism and anatexis. Migmatite dome was composed of metasediment, migmatite and migmatitic granite-gneiss. The closely spatial relationship between metasediments, migmatites and migmatitic granite-gneiss in the district exhibits the entire process of transformation from sediments to granitic rocks by metamorphic differentiation, migmatization and partial melting. From cetre to marginal zone of the migmatite dome, metasediment zone, migmatite zone and migmatitic granite- gneiss zone were regularly arranged,exhibiting the relationship between metamorphic reaction and migmatization metasomatism. During the formation of the migmatite dome by metamorphism, migmatization and partial melting, phosphorus was transported and crystallized and recrystallized in the contract zone between the metasediment zone and the migmatite zone. The metallogenesis of the creep flow fold is clear in the metasediment zone of migmatite dome.