發(fā)布時間：2018-03-13 13:48

  本文選題：成礦流體　切入點：巖石地球化學(xué)　出處：《中國地質(zhì)大學(xué)(北京)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：小興安嶺-張廣才嶺成礦帶是我國重要的鉬成礦帶之一,主要成礦類型為斑巖型和矽卡巖型,其成礦主要與燕山早期太平洋板塊俯沖作用有關(guān)。高崗山斑巖型鉬礦床是小興安嶺-張廣才嶺成礦帶上首次發(fā)現(xiàn)的早三疊世成礦的斑巖型鉬礦床,研究程度很低。本文在野外調(diào)查的基礎(chǔ)上,對高崗山鉬礦床進(jìn)行了一定室內(nèi)研究,主要包括光薄片鑒定、巖礦石地球化學(xué)分析、成礦流體包裹體測試,并進(jìn)一步探討了該礦床的成因。高崗山鉬礦賦礦巖體為晚二疊世花崗巖小巖株,受巖漿巖、地層、構(gòu)造和圍巖蝕變的復(fù)合控制,顯示典型斑巖型鉬礦床特點。區(qū)內(nèi)主要侵入巖為花崗斑巖、似斑狀花崗巖、花崗閃長巖,成礦巖體屬于過鋁質(zhì)、橄欖粗玄巖系列的S型花崗巖。區(qū)內(nèi)斑狀花崗巖為成礦提供了有利的圍巖條件。硅化、鉀化等圍巖蝕變控制了礦石類型,空間展布以及礦化強(qiáng)度。礦床結(jié)構(gòu)主要有斑狀結(jié)構(gòu)、似斑狀結(jié)構(gòu)、環(huán)帶結(jié)構(gòu)等,礦石構(gòu)造主要為片麻狀構(gòu)造、脈狀構(gòu)造、浸染狀構(gòu)造、細(xì)脈浸染狀構(gòu)造、星點狀構(gòu)造和角礫狀構(gòu)造等。高崗山鉬礦床床與典型斑巖型鉬礦床成礦階段相似,分為4期,分別為:(Ⅰ)石英-鉀長石階段;(Ⅱ)石英-黃鐵礦-磁黃鐵礦±輝鉬礦階段;(Ⅲ)石英-黃鐵礦-輝鉬礦階段;(Ⅳ)石英-方解石±螢石階段。成礦巖體巖石地球化學(xué)特征顯示其形成環(huán)境為大陸碰撞環(huán)境。成礦地球動力學(xué)背景可能與 佳蒙地塊‖與華北地塊北段東緣的碰撞拼合作用有關(guān)。對各成礦階段的礦物中的流體包裹體進(jìn)行測試,測試結(jié)果顯示高崗山鉬礦床的成礦流體具有中-高溫、中-低鹽度的特征,其成礦深度屬于中淺成。各成礦階段包裹體均一溫度、成礦流體鹽度、成礦流體密度隨著成礦作用的進(jìn)行都具有降低的趨勢。在石英中可以發(fā)現(xiàn)包裹體沸騰的證據(jù),輝鉬礦、黃鐵礦等金屬礦物沉淀主要是由于流體包裹體的沸騰作用。高崗山鉬礦床在礦體特征、礦物組成、礦物組構(gòu)以及圍巖蝕變特征均顯示出斑巖型鉬礦床的特征。
[Abstract]:The Xiaoxinganling-Zhang Guangxiling metallogenic belt is one of the important molybdenum metallogenic belts in China. The main metallogenic types are porphyry type and skarn type. The porphyry molybdenum deposit in the early Yanshanian early Yanshanian Pacific plate is the first discovered porphyry molybdenum deposit in the Xiaoxinganling-Zhangguangciling metallogenic belt. On the basis of field investigation, a laboratory study of the Gaogangshan molybdenum deposit has been carried out, including the identification of thin sheets, geochemical analysis of rocks and ores, and fluid inclusions testing of ore-forming fluids. The genesis of the deposit is further discussed. The host rock body of the Gao Gang Mountain molybdenum deposit is a small granite rock strain of late Permian, which is controlled by the composite of magmatic rocks, strata, structures and wall rock alteration. The main intrusive rocks in the area are granitic porphyry, porphyry like granite, granodiorite, and ore-forming rock mass is peraluminous. The porphyry granites in the area provide favorable surrounding rock conditions for metallogenesis. The alteration of surrounding rock such as silicification and potassium mineralization controls the ore type, spatial distribution and mineralization strength. The deposit structure is mainly porphyry structure. The ore structure mainly consists of lamellar structure, vein structure, disseminated structure, vein-like structure, vein-like structure, and vein-like structure. The deposit of the Gao Gang mountain molybdenum deposit is similar to the metallogenic stage of typical porphyry molybdenum deposits and is divided into four stages. They are respectively: (I) quartz-potassium feldspar stage (鈪，

本文編號：1606646