Sm-Nd age dating of high-pressure granulites and amphi-bolite from Sanggan area,North China craton  

作　　者：Jinghui Guo Mingguo Zhai 

机构地区：[1]Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China

出　　处：《Chinese Science Bulletin》2001年第2期106-111,共6页

基　　金：the National Natural Science Foundation of China (Grant Nos. 49972064 and 49832030).

摘　　要：The high pressure (HP) metamorphic age has been dated to HP rocks from the Sanggan area, North China craton. We have got garnet+whole rock isochron ages of (1 842±38) Ma for HP granulite, and (1 856± 26) Ma for HP amphibolite. The Sm-Nd whole rock isochron of HP granulites give out an age of (1870±150) Ma with Nd depleted mantle model age of (2402-2 482) Ma. Considering the Nd isotope homogenization during the peak metamorphism of the HP granulite, Sm-Nd closure temperature and the retention of Nd isotopic memory in garnets partially broken down during decompression, all these isochron ages are thought to be HP metamorphic age. Furthermore, we proposed that the HP metamorphism took place at the end of Paleoproterozoic during the large-scale collision and assembly of the North China craton.The high pressure (HP) metamorphic age has been dated to HP rocks from the Sanggan area, North China craton. We have got garnet+whole rock isochron ages of (1 842±38) Ma for HP granulite, and (1 856 ±26) Ma for HP amphibolite. The Sm-Nd whole rock isochron of HP granulites give out an age of (1870±150) Ma with Nd depleted mantle model age of (2402–2482) Ma. Considering the Nd isotope homogenization during the peak metamorphism of the HP granulite, Sm-Nd closure temperature and the retention of Nd isotopic memory in garnets partially broken down during decompression, all these isochron ages are thought to be HP metamorphic age. Furthermore, we proposed that the HP metamorphism took place at the end of Paleoproterozoic during the large-scale collision and assembly of the North China craton.

关 键 词：SM-ND DATING high pressure GRANULITE Paleoproteroz-oic collision North China craton. 

分 类 号：P597[天文地球—地球化学]