本文選題：礦床地質(zhì)　切入點(diǎn)：成礦流體地球化學(xué)　出處：《中國(guó)地質(zhì)大學(xué)(北京)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：安徽桂花沖銅礦床位于銅陵礦集區(qū)沙灘腳礦田內(nèi),是一個(gè)新發(fā)現(xiàn)的以發(fā)育斑巖型礦體為主的斑巖-矽卡巖復(fù)合型銅礦床。該礦床在產(chǎn)出位置和礦床類(lèi)型方面均有別于銅陵礦集區(qū)以矽卡巖型為主的其它礦床。本文通過(guò)野外調(diào)查與室內(nèi)分析研究,查明了桂花沖銅礦床的地質(zhì)特征以及斑巖型礦體成礦流體地球化學(xué)特征,并探討了其成礦流體的來(lái)源、演化及成礦過(guò)程。桂花沖銅礦床的蝕變礦化具有明顯的空間分帶特征,自斑巖體向地層依次出現(xiàn)花崗閃長(zhǎng)斑巖、鉀化帶、黃鐵絹英巖化帶、高嶺土化帶、青磐巖化帶、矽卡巖化帶以及大理巖。礦體賦存于斑巖體內(nèi)部及斑巖體與大理巖的接觸帶內(nèi)。考慮到矽卡巖期礦化不發(fā)育,本文主要對(duì)斑巖期成礦過(guò)程展開(kāi)研究,根據(jù)地質(zhì)體相互穿插關(guān)系和礦物共生組合特征可將斑巖期蝕變礦化過(guò)程劃分為鉀化、絹英巖化、石英黃鐵礦、石英多金屬硫化物和碳酸鹽五個(gè)階段。流體包裹體的研究顯示,絹英巖化階段主要發(fā)育純氣體包裹體、含子礦物包裹體及富氣相包裹體,石英黃鐵礦階段主要發(fā)育純氣體包裹體、含子礦物包裹體、富氣相包裹體及富液相包裹體,石英多金屬硫化物階段以及碳酸鹽階段主要發(fā)育富液相包裹體。從早期絹英巖化階段到晚期碳酸鹽階段,成礦流體經(jīng)歷了從高溫(472.9℃)、高鹽度(47.7~67.9%Na Cleqv.)向中低溫(140.2℃~280.3℃)、低鹽度(1.6~7.7%Na Cleqv.)的持續(xù)演化。成礦壓力主要集中在1.0~49.0MPa,對(duì)應(yīng)的成礦深度為0.6~2.0km。氫氧同位素分析表明,早期成礦流體主要以巖漿熱液為主,晚期則明顯有大氣降水的加入。成礦過(guò)程中流體經(jīng)歷了沸騰作用及混合作用,其中巖漿熱液與大氣降水的混合作用是導(dǎo)致成礦物質(zhì)沉淀的主要機(jī)制。
[Abstract]:The Guihuachong copper deposit in Anhui Province is located in the Xiaodao Orefield in Tongling Ore concentration area. It is a newly discovered porphyry skarn complex copper deposit, which is mainly developed porphyry orebody. The deposit is different from other ore deposits in occurrence location and deposit type in Tongling ore concentration area, which is dominated by skarn type. Through field investigation and indoor analysis, The geological characteristics of Guihuachong copper deposit and the geochemical characteristics of ore-forming fluid of porphyry orebody are found out, and the origin, evolution and metallogenic process of ore-forming fluid are discussed. The alteration mineralization of Guihuachong copper deposit has obvious spatial zonation characteristics. There are granodiorite porphyry zone, kalitization zone, Huangtiequanite zone, kaolinization zone, Qingpan petrolization zone, etc. The orebodies occur in porphyry body and contact zone between porphyry and marble. Considering that the mineralization of skarn period is not developed, the ore-forming process of porphyry period is studied in this paper. The porphyry alteration and mineralization process can be divided into five stages according to the interpenetrating relationship of geological bodies and mineral symbiotic assemblages. The study of fluid inclusions shows that the alteration and mineralization processes of porphyry epoch can be divided into five stages: potassium, sericite, quartz pyrite, quartz polymetallic sulphide and carbonate. The pure gas inclusions are mainly developed in the sericite stage, the submineral inclusions and the gas-rich inclusions are mainly developed, while the pure gas inclusions, the submineral inclusions, the gas-rich inclusions and the liquid-rich inclusions are mainly developed in the quartz pyrite stage. The quartz polymetallic sulphide stage and carbonate stage are mainly rich in liquid inclusions, from the early sericite stage to the late carbonate stage, The ore-forming fluid has undergone a continuous evolution from high temperature (472.9 鈩，

本文編號(hào)：1572963