【摘要】 分布于巴音诺日公地区的中三叠世花岗岩可分为两个超单元。早超单元属陆—陆碰撞同造山期S型花岗岩,单颗粒锆石U-Pb同位素年龄值234±8Ma;晚超单元属陆—陆碰撞造山后—非造山期A型花岗岩,单颗粒锆石U-Pb同位素年龄值235±4Ma。说明该区中三叠世华北板块与塔里木板块发生陆—陆碰撞造山,随后地壳的构造环境由挤压向拉张转化。更多还原

【Abstract】 The granites of middle Triassic can be divided into two superunits in Bayinnuorigong area, Inner Mongolia. The early one is coorogenic Stype granites of continentcontinent collision, which UPb age is 234 ± 8Ma;the late one is postorogenic and anorogenic Atype granites, which UPb age is 235±4Ma. It shows that the collision between North China Block and Siberia Block occurred in middle Triassic, followed by transformation of tectonic background from press to extension.更多还原