栾川群强烈热事件终止时间的确定  

DETERMINATION OF END TIME OF INTENSIVE GEOLOGICAL THERMAL PROCESS IN LUANCHUAN GROUP

作　　者：鲁祖惠[1] 胥爱军[1] 陈冬荣[1] 王玉金[1] 李友明[1] 郭士伦 郝秀红 关保德 陶自强 

机构地区：[1]郑州大学物理系,郑州大学分析测试中心,郑州大学系统科学与数学系,中国原子能研究院,河南省地质科学研究所

出　　处：《郑州大学学报（自然科学版）》1994年第1期51-55,共5页Journal of Zhengzhou University (Natural Science)

基　　金：河南省基础与应用科学研究所资助

摘　　要：秦岭造山带由华北陆块与扬子地台发生陆——陆碰撞形成，秦岭带形成后又经历了一个新的构造热活动时期．由于该地区缺乏化石和热事件造成同位素严重丢失，确定它的形成年代和强烈热事件的终止时间比较困难．本文利用裂变径迹年代学方法，测量了秦岭栾川群大红口组，磷灰石的表现年龄．在９０％的置信水平下确定奕川群形成年代下限大于５５０±３８Ｍａ，后期强烈热事件的终止时间为２４８±３５Ｍａ．Qunling mountains formed by the colllsion of the North China carton with theYangthze carton,ever experienced a late structural thermal process.It decayed the equilibriums ofisotopic systems and the fossils being scarce in this region, resulted in difficulty to determine its form-ing time and the end time of its late thermal process. The forming time of Dahongkou part,Luanchuan group and its late thermal process and time are calculated with the fission track dating ofthe apatite seperated from the metamorphic rock samples collected in this region. It is shown that thelow limit of its forming time is 550±38Ma, and the end time of its intensive thermal process record-ed in Qinling orogenic zones and ther geological systems is 248±35Ma.

关 键 词：裂变径迹 强烈热事件 栾川群 年代学 终止时间 

分 类 号：P597.3[天文地球—地球化学]