【摘要】 单锆石铅同位素蒸发法年龄研究表明，扬子克拉通北缘米仓山地区基底变质岩系中后河岩群形成于晚太古宙—早元古宙，火地垭群形成于中上元古宙；之后在晋宁运动晚期和澄江期各发生了一次大规模的构造热事件。更多还原

【Abstract】 It is assumed that the age of the Houhe rockgroup is Late Archean to Early Protorozoic and that the age of the Huodiya Group is MesoNew Proterozoic in the metamorphic basement of the Northern margin of the Yangtze craton by the studying on the Pb isotopic geochronology of single zircon.It is substaintiated that there were two very important tectonothermal events at Late Jinningian and Chengjianggian respectively.更多还原