Electron microprobe monazite Th-Pb dating and its constraints on multi-stage metamorphism of low-pressure pelitic granul
Monazites from low-pressure pelitic granulite of the Jingshan Group in the Jiaobei terrane were dated by the electron microprobe method. Three stages of metamorphic age at 1720±15 Ma, 1687±16 Ma and 1568±15 Ma were yielded by constructing age mapping for zoned monazites and PbO-ThO2* isochron diagram for unzoned monazites, respectively. The first age was interpreted as the age of an early amphibolite-facies metamorphism, the second age as the peak granulite-facies, and the last age as uplifting of the granulite unit. These ages are the first geochronologic data for the low-pressure pelitic granulites in the Jingshan Group, and thus are of important significance when discussing the tectono-metamorphic evolution of the Jiaobei terrane.
作 者： ZHOU Xiwen WEI Chunjing GENG Yuansheng ZHANG Lifei 作者单位： ZHOU Xiwen(Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China;The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China)WEI Chunjing,ZHANG Lifei(The Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China)
GENG Yuansheng(Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China)
刊 名： 科学通报（英文版） SCI 英文刊名： CHINESE SCIENCE BULLETIN 年，卷(期)： 2005 50(10) 分类号： P5 关键词： low pressure pelitic granulite electron microprobe monazite Th-Pb dating multi-stage metamorphism