现代地质2017，Vol.31Issue(2)：267-277,11.
云南因民铁铜矿区辉长岩类中黑云母-金红石化特征及其指示意义
Mineralization Characteristics and Indication Significance of Biotite-Rutile from the Gabbro Intrusions in the Yinmin Iron-Copper District, Yunnan Province
摘要
Abstract
In order to discuss the metallogenetic and diagenetic environment of iron oxide-copper-gold type deposit,the mineral-geochemical characteristics of biotites,rutiles,chlorites and ankerites of gabbro intrusions in the depth of Yinmin iron-copper district,Yunnan Province were analysed.Rutiles were derived from magmatic crystallization and multiple-stages alteration.The crystallization temperature of rutiles ranged from 820 to 1,082 ℃,and the multi-phases alteration temperature of rutiles ranged from 444 to 730 ℃.Rutiles had a symbiotic relationship with biotites.The biotites were divided into three types:Ti-rich magnesial biotites crystallised from magma,magnesial biotite and ferruginous biotite due to hydrothermal alteration.The crystallization temperature of the primary Ti-rich magnesial biotites ranged from 653 to 750 ℃,the alteration temperature of hydrothermal magnesial biotites ranged from 525 to 619 ℃,and that of hydrothermal ferruginous biotites ranged from 551 to 577 ℃.The oxygen fugacity of all the biotites was near Ni-NiO,indicating that biotites formed in the high oxygen fugacity environment,which was conducive to the formation of rutiles.In conclusion,both of biotites and rutiles formed in the environment with high temperature and oxygen fugacity.Ankerite-siderite alteration was developed in the later stage,forming in the strongly reduced and alkaline environment,playing a corrosive role to rutiles.The alteration temperature of chlorites,which were altered from ferromagnesian,such as biotites,hornblende and pyroxene,ranged from 174 to 243 ℃.The oxygen fugacity was from-44.68 to-51.42,and the sulphur fugacity was from-14.42 to-19.76,showing that chlorites formed in an environment with low-medium temperature,low oxygen fugacity and high sulphur fugacity,which was benefit to the formation of metal sulfide.In sum,the stages of magmatic crystallization,biotitization and rutiles mineralization were characterized by geochemical lithofacies with high temperature and strong oxidization,which was benefit to the Ti-Fe mineralization.Strong reducing geochemical lithofacies followed,which was favorite for the formation of metal sulfide.Above all,the superposition and evolution of geochemical lithofacies were benefit to the iron oxide-copper-gold type deposit mineralization.关键词
因民铁铜矿区/辉长岩类岩体/黑云母化/金红石化/云南Key words
Yinmin iron-copper district/gabbro intrusion/biotitization/rutile mineralization/Yunnan分类
天文与地球科学引用本文复制引用
孙紫坚,方维萱,鲁佳,王同荣,郭玉乾,宋丽红..云南因民铁铜矿区辉长岩类中黑云母-金红石化特征及其指示意义[J].现代地质,2017,31(2):267-277,11.基金项目
国家科技部转制院所专项资金项目“铁氧化物铜金型矿床元素赋存状态及构造岩相学填图技术研发”(2011EG115022,2013EG115018). （2011EG115022,2013EG115018）
