滇西保山地块金厂河铁铜铅锌多金属矿床电气石地球化学特征  

Geochemical characteristics of tourmaline in the Jinchanghe iron-copperlead-zinc polymetallic deposit in the Baoshan block in the western Yunnan

作　　者：李方兰 刘学龙[1] 李守奎 王基元[2] 陆波德 李庆锐[2] 张卫文[2] 王海 曹振梁 周杰虎 LI Fanglan;LIU Xuelong;LI Shoukui;WANG Jiyuan;LU Bode;LI Qingrui;ZHANG Weiwen;WANG Hai;CAO Zhenliang;ZHOU Jiehu(Faculty of Land Resource Engineering,Kunming University of Science and Technology,Kunming Yunnan 650093,China;Yunnan Gold&Mining Group Co.Ltd.,Kunming Yunnan 650299,China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093 [2]云南黄金矿业集团股份有限公司,云南昆明650299

出　　处：《矿物学报》2024年第6期911-926,共16页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(编号:42362010);云南黄金集团校企合作项目(编号:KKF02021212097)。

摘　　要：金厂河Fe-Cu-Pb-Zn矿床处于滇西保山地块北部。本文以金厂河矿床新近发现的电气石为研究对象,结合野外地质调查与岩相学研究,采用电子探针与激光剥蚀技术对三种不同产状的电气石(TurⅠ、TurⅡ、TurⅢ)进行成分分析测试。其中,TurⅠ呈团斑状,粒径较小;TurⅡ为针柱状,粒径中等;TurⅢ集合体呈束状、扇状与放射状,具规则外形,粒度较大。分析结果显示,矿区内产出的电气石属碱性电气石中的黑电气石-镁电气石固溶体系列,其替代机制有FeMg_(–1)、Fe^(3+)Al_(–1)与^(x)□Al(NaR^(2+))_(–1)。金厂河矿床的电气石具有Eu正异常和Ce负异常,指示其形成时的f_(O_(2))相对较高。此外,不同产状电气石的稀土配分曲线相似,表明它们主要形成于同一热液体系。金厂河矿床中电气石的形成主要与变质沉积岩和变质火山岩相互作用的流体有关。The Jinchanghe iron-copper-lead-zinc deposit is located in the northern part of the Baoshan block in the western Yunnan.In this paper,the newly discovered tourmaline in the Jinchanghe deposit is taken as the research object.Combined with the field geological investigation and petrographic observation,the electron probe and laser ablation analytical techniques have been used to analyze compositions of tourmalines in three different occurrences(TurI,TurII,and TurIII).The TurI tourmaline occurred mainly in patchy aggregates of small particles;The TurII tourmaline occurred in needle-column crystals with medium sizes;The TurIII tourmaline occurred mainly in bundle-,fan-,and radial-shaped aggregates with relatively large sizes of euhedral crystals.Based on analytical results,tourmalines in the deposit belong to the schorl-dravite solid solution series of the alkaline tourmaline with substitution mechanisms of FeMg_(–1),Fe^(3+)Al_(–1) and xAl(NaR^(2+))_(–1).Generally,tourmalines of the deposit are predominantly characterized with positive Eu anomalies and negative Ce anomalies,indicating that they were formed in a relatively high oxygen fugacity(fO2)environment.In addition,tourmalines with different occurrences have similar REE distribution patterns,indicating that they were mostly fromed in a same hydrothermal system.It is believed that the formation of tourmalines in the Jinchanghe deposit was mainly related to the interaction of fluids sourced from metasedimentary rocks and metamorphic volcanic rocks.

关 键 词：保山地块 金厂河Fe-Cu-Pb-Zn矿床 电气石 地球化学特征 替换机制 

分 类 号：P57[天文地球—矿物学] P59[天文地球—地质学]