文章摘要
许家斌.四川可尔因矿田李家沟伟晶岩型稀有金属矿床锡石LA-MC-ICP-MS U-Pb定年及地质意义[J].地质与勘探,2020,56(2):346-358
四川可尔因矿田李家沟伟晶岩型稀有金属矿床锡石LA-MC-ICP-MS U-Pb定年及地质意义
LA-MC-ICP-MS U-Pb dating of cassiterite from the Lijiagou pegmatite-type rare-metal deposit in the Ke’eryin orefield, Sichuan Province and its geological implication
投稿时间:2019-08-05  修订日期:2019-10-18
DOI:10.12134/j.dzykt.2020.02.010
中文关键词: 锡石 U-Pb定年 晚三叠世 李家沟稀有金属矿床 可尔因 松潘-甘孜造山带
英文关键词: cassiterite, U-Pb dating, Lijiagou rare-metal deposit, Ke’eryin, Songpan-Garze fold belt
基金项目:国家自然科学基金项目(编号:41702074)、四川省科技厅应用基础研究项目(编号:2019YJ0285)、四川省教育厅自然科学重点项目(编号:17ZA0039);成都理工大学中青年教学骨干教师资助项目(编号:JXGG201701)资助
作者单位E-mail
许家斌 四川省地质矿产勘查开发局一○六地质队四川温江 自然资源部构造成矿成藏重点实验室成都理工大学地球科学学院四川成都 四川能投锂业有限公司四川成都 四川省地质矿产勘查开发局化探队四川德阳 feiguangchun07@cdut.cn 
摘要点击次数: 2682
全文下载次数: 873
中文摘要:
      李家沟伟晶岩型锂铌钽铍锡稀有金属矿床位于松潘-甘孜造山带中部、可尔因矿田东南部,是近年新发现的超大型矿床,成矿时代尚不清楚。本文在伟晶岩地质特征研究的基础上,对李家沟锂辉石伟晶岩中的锡石矿物开展电子探针成分分析以及LA-MC-ICP-MS U-Pb定年工作。电子探针波谱定量分析结果显示,李家沟矿床的锡石都是与稀有金属矿床有关的锡石,并非来自热液矿床的锡石。U-Pb定年结果显示,含锂辉石钠长石伟晶岩样品(LPD4H2)的207Pb/206 Pb-238U/207 Pb 谐和年龄为203±5 Ma(n=23,MSWD=4.1),与含锂辉石矿伟晶岩的锆石U-Pb年龄基本一致,可以代表稀有金属伟晶岩脉的年龄。表明李家沟稀有金属矿床形成于晚三叠世,与印支晚期的岩浆热液活动密切相关。区域成岩成矿年代学对比显示,李家沟与雪宝顶和甲基卡等矿床具有相似的成矿类型和成矿年龄,形成于造山后趋于稳定阶段。松潘-甘孜造山带印支晚期-燕山早期存在大规模的锂铌钽铍锡稀有多金属成矿事件。
英文摘要:
      The Lijiagou deposit in the southwest of Ke’eryin orefield, Sichuan Province is a newly discovered pegmatite-type rare-metal deposit within the central Songpan-Garze fold belt (SGFB), while its age of formation and mineralization of the pegmatite remains unclear. To address these issues, based on the geological characteristics of pegmatite in Lijiagou deposit, this work analyzed major chemical compositions and made laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) dating of cassiterite. Electron-microprobe analyser (EMPA) analyses indicate that the cassiterite from the Lijiagou deposit is related to the rare-metal deposit, not from the hydrothermal deposit, which can represent the age of the rare metal deposit. The cassiterite has a Tera-Wasserburg lower intercept age of 203±5Ma (n=23, MSWD=4.1), which is identical to the zircon U-Pb age and thus represents the emplacement age of the pegmatite dikes. The results indicate that the Lijiagou rare metal deposit was formed in the late Triassic and was closely related to the magmatic hydrothermal activity in the late stage of the Indosinian period. The regional metallogenic ages comparison shows that the Xuebaoding, Lijiagou and Jiajika deposits have similar mineralization ages, similar mineralization types, and formed in a post-orogenic stable tectonic setting. Large-scale Li-Be-Nb-Ta-Sn rare-metal polymetallic events occurred in the Late-Indosinian and Early Yanshanian in the SGFB.
查看全文   查看/发表评论  下载PDF阅读器
关闭