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老君山和秦岭梁岩体具有明显的岩浆混合特征。岩体中暗色包体发育,主要类型为细粒闪长质和二长质的岩浆包体,有的岩浆包体具有细粒边,有的和寄主岩石呈过渡关系。包体的矿物组合明显不平衡:出现石英-角闪石眼斑;暗色矿物中有石英包裹体;磷灰石呈针状。在包体、寄主岩石及其边界上广泛出现卵球状的碱性长石斑晶。这些混合特征表明:老君山和秦岭梁环斑结构花岗岩、环斑结构与岩浆混合关系紧密;岩浆作用也具双峰式的特点,表现为基性岩浆和酸性岩浆的混合。这为探讨该类花岗岩和环斑结构的成因提供了直接的岩石学依据。同时,也为探讨北秦岭中生代壳幔混合作用和地壳增生提供了新的信息。
Laojunshan and Qinling Liangyan have obvious magma mixing characteristics. The dark inclusions in rock mass are developed. The main types are fine-grained dioritic and diopside magma inclusions. Some magma inclusions have fine-grained edges and some transitional to host rocks. Significantly unbalanced mineral assemblages in the inclusions: quartz-amphibole ocular spots appear; dark-colored minerals have quartz inclusions; apatite acicular. The ovoid globular feldspar phenocrysts appear widely on the enclaves, host rocks and their boundaries. These mixed features show that the granite in the Laoluoshan and Quling Mountains is closely related to magma mixing, and the magmatism is characterized by a bimodal pattern characterized by a combination of basic magma and acidic magma. This provides a direct petrological basis for exploring the genesis of this kind of granites and ring-spot structures. At the same time, it also provided new information for exploring Mesozoic crust-mantle mixing and crustal accretion in the North Qinling Mountains.