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北秦岭太白岩体位于商丹构造带北侧 ,为不同时代形成的复式深成岩体。通过 1:5万区域地质填图将该岩体共划分为 7个岩石谱系单位 ,厘定为 2个超单元 ,即北部的五里峡超单元和南部的红崖河超单元 ,依据同位素测年结果和超单元间相互关系 ,确定五里峡超单元主体侵位时代为志留纪 ,红崖河超单元侵位时代为三叠纪。从岩体周边到中心 ,从北到南 ,侵位时代从早到晚 ,显示半环带状侧向推挤迁移侵位型式。岩石地球化学资料研究证明 ,五里峡超单元形成于活动陆缘火山弧构造环境 ,岩浆源于中上地壳 ;红岩河超单元形成于同碰撞构造环境 ,岩浆源于中下地壳。
The North Qinling Taibai granite is located on the northern side of Shangdan structural belt and is a complex deep pluton formed in different times. This rock mass is divided into seven rock pedigree units by 1: 50000 regional geological mapping, and is determined as two super units, that is, the Wuliqia super unit in the north and the Hongyahe unit in the south. Based on the isotopic dating The results show that the main emplacement age of Wuli Gorge is Silurian, and the age of the Hongya River superposition unit is Triassic. From the periphery of the rock mass to the center, from north to south, the emplacement age from early to late, showing the half-annulus lateral push migration emplacement type. The study of lithogeochemical data shows that the Wuli Gorge super-unit is formed in the active land-edge volcanic arc tectonic setting, and the magma originates from the middle-upper crust. The Hongyanhe super unit is formed in the same collision environment and the magma originates from the middle and lower crust.