Zircon U-Pb ages and Hf isotopic characteristics of the Dehe biotite monzonitic gneiss pluton in the North Qinling orogen and their geological significance  

作　　者：Wang, Fei  Zhu, Laimin  Li, Jiming  Lee, Ben  Gong, Hujun  Yang, Tao  Wang, Wei  Xu, Ao 

机构地区：[1] State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China [2] Yiwu Business Technology Institute, Yiwu 322000, China

出　　处：《Chinese Journal Of Geochemistry》2011年第2期204-216,共13页中国地球化学学报

基　　金：supported jointly by the National Natural Science Foundation of China (Grant Nos. 41030423,41072068 and 40872071);National Basic Research Program of China (Grant No. 2006CB403502);MOST Special Fund from the State Key Laboratory of Continental Dynamics, Northwest University (Grant No. BJ091349);National Found for Fostering Talents of Basic Sciences (Grant No. J0830519);Graduate Innovation and Creativity Funds of Northwest University,China (Grant No. 10YZZ24)

摘　　要：The Dehe granitic pluton intruded the Xiahe Group which is in the core complex of the North Qinling Orogenic Belt(NQOB).It shows gneissic bedding and possesses typical S-type granite minerals such as muscovite and garnet.LA-ICP-MS U-Pb isotopic dating of the Dehe granite yielded a weighted average age of 925±23 Ma which represents the emplacement age of the pluton.Most of the εHf(t) values are negative,and the two-stage model ages are consistent with the age of the Qinling Group.The isotope data show that the Dehe granite was formed in the following geological setting:in the syn-collision setting of the NQOB in the Neoproterozoic,crustal thickening induced partial melting of materials derived from the Qinling complex,and then the maga upwelled and intruded into the Xiahe Group.The formation of the Dehe S-type granite implied the occurrence of a convergent event in the QOB during the Neoproterozoic.The Dehe granitic pluton intruded the Xiahe Group which is in the core complex of the North Qinling Orogenic Belt(NQOB).It shows gneissic bedding and possesses typical S-type granite minerals such as muscovite and garnet.LA-ICP-MS U-Pb isotopic dating of the Dehe granite yielded a weighted average age of 925±23 Ma which represents the emplacement age of the pluton.Most of the εHf(t) values are negative,and the two-stage model ages are consistent with the age of the Qinling Group.The isotope data show that the Dehe granite was formed in the following geological setting:in the syn-collision setting of the NQOB in the Neoproterozoic,crustal thickening induced partial melting of materials derived from the Qinling complex,and then the maga upwelled and intruded into the Xiahe Group.The formation of the Dehe S-type granite implied the occurrence of a convergent event in the QOB during the Neoproterozoic.

关 键 词：the North Qinling Orogenic Belt Dehe granitic pluton zircon U-Pb age Hf isotope geological setting 

分 类 号：P59[天文地球—地球化学]