论文部分内容阅读
本文依据西秦岭北带2处侏罗纪火山岩分布特征、剖面结构、岩石组合、岩相、喷发类型、岩石地球化学及与周边各地质体接触关系等实际资料综合分析,认为其形成的构造环境为陆内断陷盆地,喷发类型为裂隙式和中心式,岩相为溢流相和火山通道相,推测岩浆来自壳源,为元古界秦岭群中深变质岩部分熔融产物。侏罗纪该区以浅层次断陷(伸展)作用为主,侏罗纪末再次发生陆内造山作用,具有脆性断层逆冲作用特征。
Based on the comprehensive analysis of the distribution characteristics of Jurassic volcanic rocks, profile structure, rock assemblage, lithofacies, eruption type, lithogeochemistry of the Jurassic volcanic rocks in the northwestern part of the West Qinling Mountains and their contact with the surrounding geology bodies, the tectonic environment For the intracontinental rift basin, the types of eruptions are fissure-type and center-type, and the facies are the overflow facies and volcanic channel facies. It is inferred that the magma came from the crust source and is a partial melting product of the mid-deep metamorphic rocks in the Proterozoic Qinling Group. In the Jurassic period, the area was mainly characterized by shallow faulted (extensional) facies, with intracontinental orogeny occurring again at the end of Jurassic and characterized by brittle faulting.