本文關(guān)鍵詞：青海省大柴旦鎮(zhèn)魚卡金礦成因探討　出處：《中國地質(zhì)大學(xué)(北京)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 魚卡金礦 礦床成因 造山型金礦 物質(zhì)來源 柴北緣

【摘要】：魚卡金礦床位于柴北緣綠梁山-雙口山一帶,圍巖為灘間山群變碎屑巖。圍巖蝕變中硅化、黃鐵礦化與金礦化關(guān)系最為密切,可作為直接找礦標(biāo)志。礦石類型以石英脈型為主構(gòu)造蝕變巖型次之。熱液成礦期可分為石英-綠簾石、石英-多金屬硫化物、黃鐵礦-石英、碳酸鹽等四個階段。礦床整體位于綠梁山大型韌性剪切帶偏上盤位置的次級斷層中,為韌性-脆性構(gòu)造轉(zhuǎn)化的部位。整個礦化帶和單一礦體,具有北側(cè)脆性變形強(qiáng)烈,南側(cè)韌性變形更強(qiáng)特征,可能指示礦體向南側(cè)伏的規(guī)律。流體包裹體均一溫度均值為227.23℃,鹽度均值5.33%,密度均值0.87 g/cm3,壓力均值59.97 MPa。成礦深度均值6.23Km。單礦體由南往北,上述參數(shù)具有逐漸變大的趨勢,反向論證了礦體向南側(cè)伏特征。包裹體氣相成分以富含CO2為主和少量的CH4。成礦流體為中低溫、低鹽度、低密度、富含CO2流體。氫氧同位素研究表明,主成礦階段石英的δD值為-58.5‰~-41.6‰,δ18OH2O值5.20~6.01‰,成礦流體主要來自于變質(zhì)水。礦石黃鐵礦硫同位素δ34S變化范圍為0.5~7.4‰,均值4.43%,變化相對較大,硫可能主要來自深源的巖漿硫,并不同程度的混入了殼源物質(zhì)。礦石鉛同位素組成為,206Pb/204Pb為18.238~18.62,均值為18.3133,207Pb/204Pb比值為15.59~15.618,均值為15.604,208Pb/204Pb為38.039~38.775,均值為38.1697,相對富集鈾鉛和略微虧損釷鉛。鉛μ值為9.45~9.51,ω值為35.64-36.85。在增長曲線圖解及構(gòu)造判別圖解上,礦石鉛同位素投點(diǎn)落在造山帶演化線上、造山帶演化線附近以及造山帶范圍內(nèi),礦石鉛主要為造山帶鉛,并不同程度的混合了殼源和幔鉛。魚卡金礦金主要以獨(dú)立礦物形式存在和固溶體的形式進(jìn)入載金礦物,礦床載金礦物主要為黃鐵礦。礦區(qū)輝長巖的成巖年齡為387.5±7.2Ma,且輝長巖普遍發(fā)生礦化、蝕變以及韌性變形等,表明金礦化時代晚于輝長巖的侵入時代,輝長巖與金成礦關(guān)系不大。魚卡金礦具有典型造山型金礦的普遍特征,應(yīng)屬于造山型金礦。
[Abstract]:Yuqia gold deposit is located in the northern margin of the Qaidam Basin in Liangshan - green SHUANGKOUSHAN area, the surrounding rock is tanjianshangroup variable clastic rocks. Rock alteration silicification, pyritization and gold mineralization was most closely related, can be used as direct prospecting. The ore types are mainly of quartz vein type tectonic altered rock type. Hydrothermal mineralization period can be divided into quartz epidote, quartz polymetallic sulfide quartz, pyrite, carbonate and so on four stages. The overall deposit is located in the green Liangshan ductile shear zone on the location of the partial secondary faults, for ductile brittle structural transformation of the area. The whole mineralization belt and single ore body, with the North strong brittle deformation, deformation characteristics of the South may indicate a stronger toughness, south side volt orebody rule. The homogenization temperature of fluid inclusions mean of 227.23 degrees, the mean salinity 5.33%, mean density of 0.87 g/cm3, the mean pressure 59.97 MPa. 6.23Km. single ore from the mean depth of mineralization The south to the north, the parameter has gradually become a big trend, south side volt reverse demonstration of orebody characteristics. Gas composition of fluid inclusion in CO2 rich CH4. and a small amount of ore-forming fluids for low temperature, low salinity, low density, CO2 rich fluid. The hydrogen and oxygen isotope studies show that D value is the main metallogenic stage of quartz -58.5% ~-41.6%, 18OH2O values of 5.20~6.01%, the ore-forming fluid mainly from metamorphic water. Ore pyrite sulfur isotope 34S changes in the range of 0.5~7.4%, the average is 4.43%, relatively large changes, sulfur may mainly come from the deep magmatic sulfur source, and to some extent mixed with crustal material. As the Pb isotopic composition of ore. 206Pb/204Pb 18.238~18.62, the mean 18.3133207Pb/204Pb ratio was 15.59~15.618, mean 15.604208Pb/204Pb 38.039~38.775, the average is 38.1697, the relative enrichment of uranium and thorium lead a slight loss of lead. Lead value is 9.45~9.51 values 35.64-36.85. in the growth curve diagram and tectonic discrimination diagrams, ore lead isotope investment fell in the evolution of orogenic belt line, orogenic belt evolution of orogenic belt and near the line within the scope of the ore lead to the orogenic belt lead, and varying degrees of mixed source crust and mantle. Ore lead fish kankin gold mainly in the form of independent minerals the existence and the form of a solid solution into the gold bearing mineral deposits of gold bearing minerals are mainly pyrite mine. Gabbro rock forming age was 387.5 + 7.2Ma, and the widespread occurrence of gabbro mineralization, alteration and ductile deformation, shows that gold mineralization in late age of gabbro intrusion age, gabbro and gold mineralization is not common. The characteristics of gold fish card has the typical orogenic gold deposits, should belong to orogenic type gold deposit.

【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：P618.51
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本文編號：1371003