| 片麻岩穹窿与伟晶岩型锂矿的成矿规律探讨 |
| |
| 引用本文： | 许志琴,付小方,赵中宝,李广伟,郑艺龙,马泽良.片麻岩穹窿与伟晶岩型锂矿的成矿规律探讨[J].地球科学,2019,44(5):1452-1463. |
| |
| 作者姓名： | 许志琴 付小方 赵中宝 李广伟 郑艺龙 马泽良 |
| |
| 作者单位： | 1.南京大学地球科学与工程学院, 内生金属矿床成矿机制研究国家重点实验室, 江苏南京 210023 |
| |
| 基金项目： | 中国地质调查局项目1212010818094国家自然基金重点项目40921001南京大学人才基金项目020614912202国土资源部行业基金项目41430212 |
| |
| 摘 要： | "片麻岩穹窿"是指中下地壳热动力过程产生的与岩浆作用(或混合岩化作用)密切相关的穹状构造,是折返造山的产物.片麻岩穹窿的形成经历了从垂直上升的地壳流导致的岩浆上涌的挤压收缩到岩体侵位的顶部伸展机制的转化过程,这一过程有利于富含锂-铯-钽型(LCT)型伟晶岩的生成和锂族元素的富集.研究表明,位于青藏高原北部的中国松潘-甘孜-甜水海印支造山带是中国大型"伟晶岩型"锂矿资源赋存的基地,松潘-甘孜东南部的超大型甲基卡型伟晶岩型锂矿带,产于具有巴罗式"低/中压-高温"变质组合的三叠纪复理石围岩中,早中生代花岗岩以及衍生的大量含锂稀土矿物的伟晶岩脉侵位有成因关系.研究认为,探究片麻岩穹窿的形成过程和构造成因机制;识别花岗岩-含矿伟晶岩的地球化学属性,揭示花岗岩浆分异作用与含矿伟晶岩相演变的成因联系,以及锂元素迁移、富集熔浆的过程;圈定三叠纪地层中巴罗式变质相带的展布,探明富锂伟晶岩矿带赋存的有利变质相带及形成的P-T条件;揭示"变形-变质-岩浆深熔-成矿"的时空耦合、制约与相互作用,再造造山过程中锂资源富集和保存的规律,以及建立成矿动力学模式;是揭示片麻岩穹窿与伟晶岩型锂矿的成矿规律的重要科学途径.
|
| 关 键 词： | 片麻岩穹窿 花岗岩 含锂伟晶岩 "变质-变形-岩浆-成矿"四位一体 锂矿 矿床学 |
| 收稿时间： | 2019-03-08 |
Discussion on Relationships of Gneiss Dome and Metallogenic Regularity of Pegmatite-Type Lithium Deposits |
| |
| Xu Zhiqin,Fu Xiaofang,Zhao Zhongbao,Li Guangwei,Zheng Yilong,Ma Zeliang.Discussion on Relationships of Gneiss Dome and Metallogenic Regularity of Pegmatite-Type Lithium Deposits[J].Earth Science-Journal of China University of Geosciences,2019,44(5):1452-1463. |
| |
| Authors: | Xu Zhiqin Fu Xiaofang Zhao Zhongbao Li Guangwei Zheng Yilong Ma Zeliang |
| |
| Institution: | (School of Earth Sciences and Engineering,State Key Laboratory for Mineral Deposits Research,Nanjing University,Nanjing 210023,China;Sichuan Geological Survey,Chengdu 610081,China;Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China) |
| |
| Abstract: | Gneiss domes develop in exhuming orogens, where they constitute an efficient mechanism for material and heat advection of continental crust during orogenesis, which is always related to magmatism (or migmatization). Dome formation may be accompanied by heterogeneous thinning of the upper crust that may occur as the ductile lower crust flows into a gneiss dome by convergent flow and lead to contraction strain in the core. During gneiss dome formation process, lithium-rich (with other rare earth elements) pegmatite is beneficial to form and hence, lead to lithium enrichment. Previous researches indicate that the Songpan-Ganzi-Tianshuihai Indosinian orogenic belt, located in the northern part of the Qinghai-Tibetan Plateau, is the "pegmatite-type" lithium mine resources base in China. The ultra-large pegmatite-type lithium belt in the southwestern of the Songpan-Ganzi occurs in the Triassic flysch which is the country rock of Barrow-type metamorphism with low/medium pressure-high temperature metamorphic traits. It has a genetic relationship with the Late Triassic granite and the lithium-bearing pegmatite intrusion. The authors suggest that future studies should focus on (1) exploring the formation process and tectonic mechanism of gneiss domes; (2) identifying the geochemical properties of granite-bearing pegmatites; (3) revealing the genetic relationship between the differentiation of granite and the evolution of ore-bearing pegmatite; (4) clarifying lithium migrating and enriching process in the melt; (5) delineating the distribution of the Barrow-type metamorphic facies belt in the Triassic strata; (6) proving the favorable metamorphic facies belts and P-T conditions where the lithium-rich pegmatite formed can reveal the space-time coupling of "deformation-metamorphism-magmatic deep-melting-metallogenesis". Moreover, the law of enrichment and preservation of lithium ore, used to establish the metallogenic kinetics model, is an important scientific aspect to reveal the relationships of gneiss dome and metallogenic regularity of pegmatite-type lithium deposits. |
| |
| Keywords: | gneiss dome granite lithium-bearing pegmatite four integrated factors of "metamorphism-deformation-magmatism-mineralization" lithium deposit mineral deposit |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《地球科学》浏览原始摘要信息 |
| 点击此处可从《地球科学》下载免费的PDF全文 |
|
