Electron microprobe chemical ages of monazite from Qinling Group in the Qinling Orogen: Evidence for Late Pan-African metamorphism?  

作　　者：CHEN Qiang CHEN Nengsong WANG Qinyan SUN Min WANG Xinyu LI Xiaoyan SHU Guiming 

机构地区：[1]Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China [2]Department of Earth Sciences, The University of Hong Kong, HongKong SAR, China [3]Guangxi Institute of Geological Survey, Nanning 5300.23, China [4]School of Earth and Space Sciences, Peking University, Beijing 100871, China

出　　处：《Chinese Science Bulletin》2006年第21期2645-2650,共6页

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.40272030 and 40234052);the Key Project of Ministry of Education of China(Grant No.104309).

摘　　要：Electron microprobe chemical dating was carried out on monazites enclosed in two gen-erations of mineral paragenesis of St + Ky + Grt and Sil + And + Grt + St, respectively, from the Qinling Group. Two different ages, 520±23 Ma and 435±9 Ma, were obtained from these monazites. This indicates that the Qinling Group experienced a metamorphism during the Early Cambrian, which is probably in response to the Late Pan-African subduction-accretion tectonothermal event.Electron microprobe chemical dating was carried out on monazites enclosed in two generations of mineral paragenesis of St ＋ Ky ＋ Grt and Sil ＋ And ＋ Grt ＋ St, respectively, from the Qinling Group. Two different ages, 520±2.3 Ma and 435±9 Ma were obtained from these monazites. This indicates that the Qinling Group experienced a metamorphism during the Early Cambrian, which is probably in response to the Late Pan-African subduction-accretion tectonothermal event.

关 键 词：化学年龄 电子显微探针 独居石 秦岭造山带 

分 类 号：P597[天文地球—地球化学]