【摘要】 本区出露有太古宙麻粒岩相的变质岩和紫苏花岗岩系。麻粒岩相晚期发生了重熔型区域性混合岩化作用,不同大小的各类变质岩残留体散布于混合岩中。紫苏花岗岩是在麻粒岩相变质作用基础上演化形成的,由含辉石麻粒岩经深部重熔伴随碱质交代而产生的一套特殊岩系。在变质岩与紫苏花岗岩系之间呈现着明显的演化和继承关系,特别在产状分布、矿物成分、化学成分、结构构造等方面都显示了其岩石成因的紧密联系。 紫苏麻粒岩和紫苏花岗岩的重熔曲线彼此间非常近似,表示形成紫苏花岗岩早期的温压条件接近麻粒岩相环境。 太古宙地块的中心部分由于高温导致强的选择性深熔作用而形成紫苏花岗岩系。更多还原

【Abstract】 Exposed in this area is an Archaean metamorphic rock series of granulite facies. There are associated Charnockite series. Regional migmatization by anatexis took place at the later stage of granulite facies. Various metamorphic residual blocks of different sizes were scattered in the migmatite. The Charnockite in this area was evolved under the condition of the metamorphism of granulite facies. It is a specific series produced by the deep remelting of pyroxene-bearing granulites accompanied with alkali-metasomatism. There are obvious eolutional and inherited relations between metamorphic rocks and Charno-ckites. Their special distribution patterns, mineral compositions, chemical compositions, textures and structures, etc. indicate their close petrogenetic relation.The remelting curves of hypersthene granulite and charnockite are very similar to each other, indicating the P-T conditions at the earlystage of charnockite were close to that of “granulite facies”.In the central part of the Archaean block, as the selective anatexis became stronger because of the high temperature, the charnockites occured.更多还原