摘要
通过对北秦岭东部各种方法年代学数据的统计分析，获得了本区自元古宙以来主要热事件的时限及地壳动力学演化的一些信息．这些热事件时限与地壳主要构造旋回是对应的．年代学数据的统计分段指示了主要构造－岩浆事件的尾声（同位素封闭时间），它们是：４００～４５０Ｍａ，６００～７００Ｍａ，９５０～１１００Ｍａ，１４００±Ｍａ，２０００～２２００Ｍａ．秦岭造山带中，秦岭群形成最早，因而经历了最复杂的变质变形史．但其独立性特征，则显示了它在元古宙可能是一些微板块（地体）．
Some information on main heat event timing and evolution of the eastern part of North Qinling rangessince Proterozoic have been obtained from the statistical analysis of different isotopic geochronologic data.Thestatistical stepping of beat event is corresponding to the crustal tectonic cycle in this area,and indicates theending time of the tectono-magmatic cycle (the isotopic systems were closed).The stepping times are 400- 450,600-700,900- 1 100, 1 400± 2 000- 2 200 (Ma),etc.Qinling Group was formed first,and thenunderwent a very complicated metamorphic - deformation procedure during the orogen. However,some features suggest that there may be some microplates (terraines) in the proterozoic.
关键词
同位素年代学
热事件
变质岩
North qinling
Qinling group
Isotopic geochronology
Heat event
Crustal evolution
