LA-ICP-MS U-Pb zircon dating of the Bozhushan granite in Southeast Yunnan  

作　　者：LI Kaiwen ZHANG Qian WANG Dapeng CAI Yi LIU Yuping 

机构地区：[1]State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《Chinese Journal Of Geochemistry》2013年第2期170-180,共11页中国地球化学学报

基　　金：supported by Hu Zhaochu and Zheng Shu of the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Wuhan);the National Natural Science Foundation of China (No. 40872074);the National Key Basic Research Program (No. 2007CB411408);the State Key Laboratory of Ore Deposit Geochemistry(No. KCZX20090106) for their financial support

摘　　要：The LA-ICP-MS U-Pb zircon dating of eight typical samples from four units of the Bozhushan granite intrusion in southeastern Yunnan Province, constrains the age of acidic magmatic intrusion in this area. Both the oscillatory zoning and chondrite-normalized REE patterns characterized by LREE-depletion and HREE-enrichment with positive Ce anomaly and negative Eu anomaly indicate the magmatic genesis of these zircons. Eight zircon samples from the Bozhushan granite yielded a mean 206 Pb/ 238 U age of (85.58±1.0) Ma (MSWD=4.1) to (88.10±0.66) Ma (MSWD=1.8). These chronology data suggest an accurate isotopic age for the intrusion of the Bozhushan granite, and are different from the published age data of 48 to 111.5 Ma. The geochronology data of the Gejiu, Dulong and Dachang super-large deposits and related Yanshanian granites indicated that there occurred large-scale granitic magmatism and mineralization events in western Nanling region during the Late Cretaceous.The LA-ICP-MS U-Pb zircon dating of eight typical samples from four units of the Bozhushan granite intrusion in southeastern Yunnan Province, constrains the age of acidic magrnatic intrusion in this area. Both the oscillatory zoning and chondrite-normalized REE patterns characterized by LREE-depletion and HREE-enrichment with positive Ce anomaly and negative Eu anomaly indicate the magmatic genesis of these zircons. Eight zircon samples from the Bozhushan granite yielded a mean 2~6pb/238U age of （85.584-1.0） Ma （MSWD=4.1） to （88.10-3：0.66） Ma （MSWD=I.8）. These chronology data suggest an accurate isotopic age for the intrusion of the Bozhushan granite, and are different from the published age data of 48 to 111.5 Ma. The geochronology data of the Gejiu, Dulong and Dachang super-large deposits and related Yanshanian granites indicated that there occurred large-scale granitic magmatism and mineralization events in western Nanling region during the Late Cretaceous.

关 键 词：U-PB同位素定年 LA-ICP-MS 燕山期花岗岩 锆石 滇东南 同位素年龄 典型样本 稀土富集 

分 类 号：P597.3[天文地球—地球化学]