發(fā)布時(shí)間：2018-05-07 13:36

  本文選題：氧逸度 + 含水性　； 參考：《中國(guó)地質(zhì)大學(xué)(北京)》2017年碩士論文

【摘要】：巖漿氧逸度和水含量對(duì)于斑巖銅礦的形成至關(guān)重要,朱諾斑巖銅礦床為岡底斯西段一典型的形成于后碰撞環(huán)境的斑巖型銅礦。礦區(qū)巖漿作用發(fā)育,主要包括成礦前約50Ma石英斑巖,成礦期13~15Ma二長(zhǎng)花崗斑巖、斑狀二長(zhǎng)花崗巖及其中的包體等,成礦晚期10~12Ma花崗斑巖。本文通過(guò)鋯石、角閃石、黑云母、斜長(zhǎng)石、磁鐵礦-鈦鐵礦、黑云母等方法研究朱諾各階段巖漿的氧逸度和含水性,并與岡底斯東段的礦床進(jìn)行區(qū)域?qū)Ρ�。朱諾成礦期包體鋯石Ce~(4+)/Ce~(3+)比值為372~919,據(jù)角閃石成分的ΔFMQ為+1.2~+3.0,水含量為4.0~4.3 wt%,據(jù)斜長(zhǎng)石成分的水含量為3.5~4.2 wt%;二長(zhǎng)花崗斑巖鋯石Ce~(4+)/Ce~(3+)比值為142~364,據(jù)角閃石成分的ΔFMQ為+2.6~+3.4,水含量為3.2~3.9 wt%,據(jù)斜長(zhǎng)石成分的水含量為2.7~3.4 wt%;斑狀二長(zhǎng)花崗巖鋯石Ce~(4+)/Ce~(3+)比值為45~182,據(jù)角閃石成分的ΔFMQ為+2.8~+3.7,水含量為2.9~3.7 wt%,據(jù)斜長(zhǎng)石成分的水含量為2.9~3.1 wt%;閃長(zhǎng)玢巖鋯石Ce~(4+)/Ce~(3+)比值為3~195,ΔFMQ為+2.7~+3.3。二長(zhǎng)花崗斑巖和包體的氧逸度、水含量明顯高于斑狀二長(zhǎng)花崗巖、閃長(zhǎng)玢巖,因此,包體或者含包體的斑狀二長(zhǎng)花崗巖及二長(zhǎng)花崗斑巖與成礦的關(guān)系最為密切。朱諾成礦前石英斑巖鋯石Ce~(4+)/Ce~(3+)比值為328~959,水含量小于2.8wt%,較成礦期的巖石具有高氧逸度低含水性的特征。成礦后花崗斑巖鋯石Ce~(4+)/Ce~(3+)比值為39~196,水含量小于3.0wt%,較成礦期巖石具有低氧逸度和低含水性的特征。本文對(duì)岡底斯東西段礦床氧逸度和含水性的對(duì)比發(fā)現(xiàn),拉抗俄成礦巖體Ce~(4+)/Ce~(3+)比值為492.25,達(dá)布成礦巖體Ce~(4+)/Ce~(3+)比值為398.37,沖江成礦巖體Ce~(4+)/Ce~(3+)比值為263.83,朱諾成礦巖體Ce~(4+)/Ce~(3+)比值為249.24;驅(qū)龍成礦斑巖、甲瑪成礦巖體的(Ce/Nd)/Y的比值大于0.01,1000(Eu/Eu*)/Y比值大于1,Eu/Eu*比值大于0.4;朱諾的成礦巖體的鋯石(Ce/Nd)/Y比值小于0.01,1000(Eu/Eu*)/Y比值小于1,Eu/Eu*比值小于0.4。朱諾斑巖銅礦床較東段的斑巖銅礦床具有更低的巖漿氧逸度和含水性,暗示岡底斯西段受到更多印度陸殼物質(zhì)的混染。
[Abstract]:The oxygen fugacity and water content of magma are very important for the formation of porphyry copper deposits. The Juno porphyry copper deposit is a typical porphyry copper deposit formed in the post-collision environment in the west section of Gangdis. Magmatism developed in the ore area, including 50Ma quartz porphyry before mineralization, 13~15Ma Erchanggranitic porphyry during metallogenic period, porphyry monzogranite and its middle inclusions, and 10~12Ma granitic porphyry in late metallogenic period. In this paper, oxygen fugacity and water content of magma at different stages of Juno are studied by means of zircon, hornblende, biotite, plagioclase, magnetite, ilmenite and biotite. In Juno metallogenic period, the ratio of zircon Ce~(4 ~ / ce ~ (3) is 372 ~ 919, according to hornblende composition 螖 FMQ is 1.2-3.0, water content is 4.0 ~ 4.3 wts, according to plagioclase composition, water content is 3.5 ~ 4.2wt.The ratio of Ce~(4 / Ce~(4 / Ce~(4 ~ (3) is 142 ~ 364, according to amphibole composition 螖 FMQ. The water content is 2.6-3.4 wt.The water content of plagioclase is 2.73.4wt.The ratio of zircon Ce~(4 / cefin 3 of porphyritic monzomorphic granite is 450.182, the 螖 FMQ of amphibole is 2.83.7w ~ 3.7w ~ (th), and the water content of plagioclase is 2.93.1wtt. the water content of the plagioclase is 2.93.1wtt, according to the plagioclase composition, the content of water is 2.93.7wtt, and the content of water is 2.93.7wtt, according to the composition of plagioclase. The ratios of zircon Ce~(4 ~ / ce ~ (3) and 螖 FMQ of diorite porphyrite are 31995 and 2.7 ~ 3.3 respectively. The oxygen fugacity and water content of Erchang granitic porphyry and xenoliths are obviously higher than that of porphyry granite and diorite-porphyrite. The ratio of zircon Ce~(4 ~ + / ce ~ (3) ~ (3) of quartz porphyry before Juno mineralization is 328959, and the water content is less than 2.8 wt. the ore-forming rocks have the characteristics of high oxygen fugacity and low water content. The ratio of zircon Ce~(4 ~ + / ce ~ (3) is 39 ~ (196), the water content is less than 3.0 wt, and the ore-forming period is characterized by low oxygen fugacity and low water content in the granitic porphyry, which is characterized by low oxygen fugacity and low water content. In this paper, the comparison of oxygen fugacity and water content in the east and west section of Gangdis ore deposit has been found. The ratio of Ce~(4 ~ / ce ~ (3) is 492.25, that of Dabu ore-forming body is 398.37, that of Chongjiang ore-forming body is 263.83, that of Juno ore-forming body is 249.24, that of Chongjiang ore-forming body is 263.83, that of Dabu ore-forming body is 398.37, that of Chongjiang ore-forming rock body is 263.83, and that of Juno ore-forming body is 249.24. The ratio of ce / NdU / Y of Jiama ore-forming rock body is greater than 0.01U / EU / EU / Y ratio > 1 / 10 EU / EU / Y ratio > 0.4, and the zircon ce / NdU / Y ratio of Juneau ore-forming rock mass is less than 0.01 / 1000 / EU / U / Y ratio < 1 EU / EU * / Y ratio < 0.4 EU / EU * / Y ratio, and the zircon / ce / NdU / Y ratio of Juneau ore-forming rock mass is less than 0.01U / NdU / Y ratio. The Juno porphyry copper deposit has lower magmatic oxygen fugacity and water bearing than the porphyry copper deposit in the eastern part, suggesting that the western Gangdis section is contaminated by more Indian continental crust materials.
【學(xué)位授予單位】：中國(guó)地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：P618.41

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