(1. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院 有色金屬成礦預(yù)測(cè)與地質(zhì)環(huán)境監(jiān)測(cè)教育部重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083;
2. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院 有色資源與地質(zhì)災(zāi)害探查湖南省重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 采用“流體包裹體組合(FIA)”的研究方法，對(duì)礦田主成礦期早、中、晚階段的流體包裹體進(jìn)行顯微測(cè)溫和拉曼探針的分析。結(jié)果表明:早階段流體包裹體主要為水溶液包裹體和CO2三相包裹體，中階段主要為富液相水溶液包裹體和CO2兩相包裹體，晚階段主要發(fā)育水溶液包裹體。從早階段到晚階段，流體包裹體的均一溫度逐漸降低，鹽度先升高再降低。3個(gè)階段中水溶液包裹體的組分主要為水，除CO2外，還檢測(cè)到少量H2S、CH4和N2。早階段成礦流體在演化過(guò)程中發(fā)生以CO2逸失為特征的流體不混溶作用，是該階段含礦流體中絡(luò)合物分解并沉淀成礦的主要因素;中階段成礦元素沉淀的主導(dǎo)因素則是流體的混合作用;而晚階段成礦元素沉淀的主導(dǎo)因素推測(cè)為流體體系的自然冷卻。
關(guān)鍵字: 成礦流體;石英脈型;鎢礦床;錫田
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and
Geological Environment Monitoring, Ministry of Education,
School of Geosciences and Info-Physics Central South University, Changsha 410083, China;
2. Key Laboratory of Non-ferrous Resources and Geological Hazard Detection,
School of Geosciences and Info-Physics Central South University, Changsha 410083, China）
Abstract:According to cross-cutting relations and minerals assemblages, three stages were cataloged in the vein type deposits:early quartz-(molybdenite)-wolframite veins, middle quartz-(wolframite)-sulfide veins and late quartz-pyrite- fluorite veins. Based on detail petrography of fluid inclusion assemblage (FIA), fluid inclusions of three stages were studied by microthermometric and Raman microspectroscopic analysis. Mainly aqueous and CO2-H2O three-phase inclusions in quartz-(molybdenite)-wolframite veins, liquid-rich aqueous and CO2 two-phase inclusions in quartz-(wolframite)-sulfide veins and only aqueous inclusions in quartz-pyrite-fluorite veins were found. The results show that the homogenization temperature of the fluid inclusions decreases from early veins to late veins, while the salinities of fluid inclusions increase in middle veins and decrease in late veins. According to Raman microspectroscopic results, the fluid inclusions of three stages is mainly H2O, moreover, minor CO2, rare H2S, CH4 and N2. The metals precipitation are fluid immiscibility caused by CO2 escaping in early stage, fluid mixing in middle stage and natural cooling of fluid system in late stage.
Key words: ore-forming fluid; quartz-vein type; tungsten deposit; Xitian
