【摘要】：河南省欒川縣石窯溝鉬礦床位于東秦嶺鉬礦帶內(nèi),是區(qū)內(nèi)新發(fā)現(xiàn)的又一典型斑巖型鉬礦床。本文在翔實礦床地質(zhì)特征的基礎上,運用礦物巖相學、流體包裹體巖相學,結合激光拉曼掃描光譜分析及穩(wěn)定同位素等研究,探討成礦流體成分、溫度、鹽度、壓力等物理化學條件和成礦流體的類型,從成礦流體的“源、運、沉”三個方面研究流體成礦作用并利用流體包裹體壓力計法估算成礦深度。石窯溝鉬礦床的鉬礦化主要呈浸染狀、細脈狀或網(wǎng)脈狀。熱液成礦過程分為3個階段:I)石英+鉀長石階段,II)石英+多金屬硫化物階段,III)石英+方解石階段。圍巖蝕變主要發(fā)育有鉀化、硅化、絹英巖化、青磐巖化、碳酸鹽化等。石窯溝鉬礦初始成礦流體為中高溫、中低鹽度的H2O-Na Cl-CO2體系巖漿熱液,熱液成礦晚階段為H2O-Na Cl體系熱液。整個成礦流體演化過程中流體包裹體的均一溫度、鹽度由191.6~437.2℃→191~484℃→132~423℃→117~247℃、2.07~16.45%Na Cleqv→3.55~57.62%Na Cleqv→3.23~50.03%Na Cleqv→2.74~8.95%Na Cleqv,表現(xiàn)出逐步降低的趨勢。其中,流體成礦過程中出現(xiàn)不混溶作用造成局部流體鹽度升高。H、O同位素組成特征表明,石窯溝鉬礦的成礦流體成礦早階段以巖漿水為主,成礦作用過程中有大氣降水的參與。區(qū)域穩(wěn)定同位素及石窯溝鉬礦Re同位素特征研究表明,成礦物質(zhì)來源具有殼�；煸吹奶卣�,但主要來自下地殼。成礦元素Mo在成礦流體以中-高溫、中-低鹽度為特征的石窯溝鉬礦中可能主要以離子對(KHMo O4)或鉬酸的形式運移;輝鉬礦的沉淀主要與流體不混溶、混合作用、物理化學性質(zhì)的轉變有關。利用沸騰包裹法和含子礦物法估算其成礦深度分別為3.7~5.2km、2.81~4.8km。綜合本次研究成果及本區(qū)其他鉬礦床成礦深度的研究,作者認為石窯溝鉬礦的成礦深度為3~5km。
[Abstract]:Shiyaogou molybdenum deposit in Luanchuan County Henan Province is located in the East Qinling molybdenum ore belt and is another typical porphyry type molybdenum deposit. On the basis of the geological characteristics of the mineralized ore deposits, this paper discusses the composition, temperature and salinity of ore-forming fluids by means of mineralogical petrography, fluid inclusion petrography, laser Raman scanning spectroscopy and stable isotopic analysis. The physical and chemical conditions such as pressure and the types of ore-forming fluids are studied from the source, transport and sedimentation of the ore-forming fluids, and the depth of ore-forming is estimated by the fluid inclusion pressure gauge method. The molybdenum mineralization of Shiyaogou molybdenum deposit is mainly disseminated, veined or reticulated. The hydrothermal metallogenic process is divided into three stages: I) quartz potassium feldspar stage II) quartz polymetallic sulphide stage III) quartz calcite stage. The main changes of surrounding rock are potassium, silicification, sericolith, Qingiranite, carbonization and so on. The initial ore-forming fluid of Shiyaogou molybdenum deposit is H2O-Na Cl-CO2 system with medium high temperature and low salinity, and the late stage of hydrothermal mineralization is H2O-Na Cl system hydrothermal solution. The homogenization temperature of fluid inclusions and the salinity of fluid inclusions gradually decreased from 191.6 ~ 437.2 鈩，

本文編號：2254827