地质科学2024，Vol.59Issue(4)：940-960,21.DOI:10.12017/dzkx.2024.067
含刚玉变沉积岩对扬子克拉通西北缘新元古代演化史的制约
Constraints of corundum bearing metasedimentary rocks on the Neoproterozoic evolution history of the northwest margin of the Yangtze Craton
摘要
Abstract
Clarifying the Precambrian metamorphic basement exposed on the northwest margin of the Yangtze Craton is of fundamental significance for revealing the tectonic evolution history of the Yangtze Craton in the Neoproterozoic and the formation and occurrence mechanism of deep resources in the Sichuan Basin.This article reveals petrogenesis of biotite plagioclase gneiss and corundum bearing sillimanite cordierite schist in the Micangshan terrane on the northwest edge of the Yangtze Craton.Combined with metamorphic research,it is believed that the formation of corundum bearing mica schist is related to the loss of SiO2 in the deep melting process of the coexisting biotite plagioclase gneiss.The temperature and pressure during the metamorphic peak recorded by the migmatitic biotite plagioclase gneiss reached 759 ℃～770 ℃,0.48～0.55 GPa(with a geothermal gradient of 46 ℃/km～53 ℃/km),while the typical mineral assemblage of corundum bearing sillimanite cordierite schist records the P-T conditions of 580 ℃～620 ℃,0.36～0.46 GPa(with a geothermal gradient of 35 ℃/km～43 ℃/km).Metamorphic zircons have reported two sets of metamorphic ages,814±9 Ma and 736±17 Ma.Based on previous research results,this article believes that the sedimentary rocks containing corundum have further finely characterized the arc-continent collision process since～814 Ma.The high temperature gradient may be related to the involvement of mantle derived materials during the collision process,and the corresponding collision process further confirms that the Yangtze Craton is located on the periphery of the Rodinia supercontinent.关键词
含刚玉变沉积岩/扬子克拉通/新元古代/变质作用Key words
Corundum bearing metasedimentary rocks/Yangtze Craton/Neoproterozoic/Metamorphism分类
天文与地球科学引用本文复制引用
张易,王浩铮,冯林峰,刘恒,薛帅朕,郭杰,崔夏红..含刚玉变沉积岩对扬子克拉通西北缘新元古代演化史的制约[J].地质科学,2024,59(4):940-960,21.基金项目
国家自然科学基金项目(编号:42072225,41702199)资助 （编号:42072225,41702199）
