地质学报2017，Vol.91Issue(5)：1039-1051,13.
西藏班戈县江错铁矿正长斑岩锆石LA-MC-ICP-MS U-Pb定年及意义
LA-MC-ICP-MS U-Pb Dating of Orthophyre from the Jiangcuo Iron Deposit in Baingoin County, Tibet and Its Geological Significance
摘要
Abstract
Three orthophyre samples were collected from the Jiangcuo iron deposit,which is located 100kmn northeast of Baingoin County.Petrographic and geochemistry study shows that the orthophyre has a SiO2 content of 59.55％ ～62.61％ (ave.61.52％) Na2O content of 9.31％ ～10.01％ (ave.9.74％),K2O content of 0.107％ ～0.12％ (ave.0.113％),with the Rittman index ranging from 5.16 to 5.36.This indicates that the rocks belong to sodic alkaline rock series.Alkaline rock of this kind was discovered for the first time in the Ban'ge area in the middle part of the Bagong-Nujiang suture belt.Zircon LA-MC-ICP-MS U-Pb dating yields an age of 1704-2.4Ma at Yanshannian Mid-Jurassic period.Comprehensive study of regional geological comparison shows that the set of orthophyre should be the product of immature island arc of of the Bangong Nujiang basin at early stage of subduction.关键词
正长斑岩/锆石U-Pb年龄/江错铁矿/班戈Key words
orthophre/zircon U-Pb age/Jiangcuo iron deposit/Baingoin引用本文复制引用
易明筱,赵元艺,汪傲,许虹,李小赛,卢伟,王贤伟..西藏班戈县江错铁矿正长斑岩锆石LA-MC-ICP-MS U-Pb定年及意义[J].地质学报,2017,91(5):1039-1051,13.基金项目
本文为中国地质调查局地质调查项目“西藏多龙矿床技术经济与环境综合评价”(编号DD20160330)和国家重点基础研究发展计划“973”项目(编号2011CB403103)联合资助成果. （编号DD20160330）
