本文選題：石英脈型金礦 + 礦床地質(zhì)�。� 參考：《中國(guó)地質(zhì)大學(xué)(北京)》2017年碩士論文

【摘要】：樊岔金礦是小秦嶺金礦集區(qū)中的一個(gè)典型的石英脈型金礦,成礦流體是石英脈型金礦形成的關(guān)鍵控制因素之一,也是礦床學(xué)研究的重點(diǎn)內(nèi)容。本文對(duì)該礦床開展了詳細(xì)的礦床地質(zhì)特征和流體包裹體研究,揭示了流體的來(lái)源與演化,并在此基礎(chǔ)上探討了礦床成因。野外調(diào)研和室內(nèi)觀察結(jié)果表明,樊岔金礦賦礦圍巖主要為太華群斜長(zhǎng)角閃片麻巖;礦體受脆性斷裂控制;圍巖蝕變主要為硅化、鉀長(zhǎng)石化、絹云母化、黃鐵礦化和碳酸鹽化。據(jù)礦物組合和脈體穿插關(guān)系將該礦成礦過(guò)程劃分為五個(gè)階段:石英鉀長(zhǎng)石化階段(Ⅰ)、石英粗粒黃鐵礦階段(Ⅱ)、石英細(xì)粒黃鐵礦階段(Ⅲ)、石英多金屬硫化物階段(Ⅳ)和碳酸鹽階段(Ⅴ)。主成礦階段為石英細(xì)粒黃鐵礦階段(Ⅲ)和石英多金屬硫化物階段(Ⅳ)。巖相學(xué)觀察顯示,該礦床流體包裹體主要相態(tài)類型為富CO2三相型、含CO2三相型和氣液兩相型。顯微測(cè)溫?cái)?shù)據(jù)顯示:從石英粗粒黃鐵礦階段到碳酸鹽階段,均一溫度峰值依次為363.3℃、325.5℃、273℃、258.6℃,總體呈逐漸降低的趨勢(shì);鹽度峰值依次為14.53、9.59、11.61、8.03 wt%NaCl.equiv.,略有起伏但變化不大,總體呈降低趨勢(shì)。礦床成礦流體屬于中低溫中低鹽度CO2-H2O-NaCl-(±CH4)成礦流體系統(tǒng)。氫氧同位素分析結(jié)果表明,成礦流體早階段主要為變質(zhì)流體,主成礦階段主要為變質(zhì)水和大氣降水組成的混合流體,晚階段以大氣降水為主;流體包裹體微觀特征及測(cè)溫?cái)?shù)據(jù)表明流體在主成礦階段發(fā)生過(guò)明顯的流體混合和流體不混溶作用。流體混合和流體不混溶是導(dǎo)致樊岔金礦金元素沉淀的主要成礦機(jī)制。
[Abstract]:Fancha gold deposit is a typical quartz vein type gold deposit in Xiaoqinling gold concentration area. The ore-forming fluid is one of the key controlling factors for the formation of quartz vein type gold deposit, and is also the key content of ore deposit study. In this paper, the geological characteristics and fluid inclusions of the deposit are studied in detail, the origin and evolution of the fluid are revealed, and the genesis of the deposit is discussed. The results of field investigation and indoor observation show that the host rock of Fancha gold deposit is mainly obliquity diorite of Taihua group, the orebody is controlled by brittle fracture, and the alteration of surrounding rock is mainly silicification, kalitization, sericite, pyrite and carbonization. According to mineral assemblage and vein intercalation relationship, the ore-forming process of this ore can be divided into five stages: quartz and potassium feldspar stage (鈪，

本文編號(hào)：1943541