【摘要】：迤納廠礦床是康滇地軸典型的鐵—銅—稀土礦床之一。因?yàn)槠涮厥獾牡V物組合(磁鐵礦與黃銅礦共生)以及富含稀土礦物,該礦床一直是礦床學(xué)家研究的熱點(diǎn)。本論文以滇中地區(qū)武定迤納廠鐵—銅—稀土礦床為研究對象,通過野外調(diào)研、室內(nèi)分析測試、用各種地球化學(xué)手段綜合研究,總結(jié)礦物組合特征,對變質(zhì)圍巖進(jìn)行原巖恢復(fù),研究金屬礦物、非金屬礦物的微量元素、稀土元素地球化學(xué)特征和元素組合特征,以及方解石C、O同位素特征和黃銅礦S同位素特征,總結(jié)成礦物質(zhì)、成礦流體來源,對礦床成因進(jìn)行了探討。結(jié)果表明:(1)礦物組合特征表明,迤納廠礦床金屬礦物與非金屬礦物之間存在著密不可分的關(guān)系。磁鐵礦、黃銅礦大都為共生關(guān)系,與方解石、螢石、鈉長石等非金屬礦物也存在著共生關(guān)系。(2)變質(zhì)原巖恢復(fù)結(jié)果:迤納廠礦床變質(zhì)圍巖主要為大陸島弧環(huán)境下形成的沉積巖(泥頁巖、石英砂巖為主)。(3)磁鐵礦和黃鐵礦元素地球化學(xué)特征表明,成礦物質(zhì)不是單純的巖漿來源,而是多種來源,局部可能為沉積來源,說明可能為沉積改造成因,表明迤納廠礦床成礦流體不是單一來源,早期巖漿成因,并有后期變質(zhì)熱液疊加作用成礦。(4)Y/Ho-La/Ho圖解顯示,迤納廠礦床不同產(chǎn)狀的螢石,流體可能為同一流體體系不同階段的產(chǎn)物;三期方解石具有比較集中的La/Ho和Y/Ho值,指示它們可能形成于某一成礦階段的相同成礦流體。螢石、方解石均主要為熱液成因。對鈉長石稀土元素地球化學(xué)研究表明,鈉長石為熱水及熱液流體形成,為熱液成因鈉長石。由共生組合關(guān)系可得,成礦金屬礦物與螢石、方解石、鈉長石關(guān)系十分密切,因此,迤納廠礦床屬于典型的熱液成因礦床。地幔流體對成礦具有重要意義。(5)通過對迤納廠礦床方解石的C、O同位素分析,得出方解石中碳可能大部分由深源碳提供,并受到大氣降水的影響以及沉積巖混染效應(yīng)影響,部分方解石成礦流體中的碳來自于海相碳酸鹽巖的溶解作用,表明迤納廠礦床成礦熱液和深部巖漿流體有很密切的關(guān)系,存在深部巖漿水、大氣降水的混合作用。對黃銅礦硫同位素的分析,表明迤納廠礦床具有IOCG礦床的特征,成礦流體來源與地幔流體緊密相關(guān),并且與淺部地殼流體和成礦物質(zhì)的混入有關(guān)。(6)通過共生組合關(guān)系,初步判斷Fe和Cu為同期成礦元素,U和REE為同期成礦元素。主要成礦期是1.6~1.7Ga左右,與昆陽裂谷的拉張及Columbia超級大陸裂解關(guān)系密切,主要形成鐵和銅;第二次成礦是0.7~0.8Ga左右,主要表現(xiàn)為鈾和稀土的富集。
[Abstract]:Yinachang deposit is one of the typical iron-copper-rare earth deposits in the Kangdian axis. Because of its special mineral assemblage (magnetite and chalcopyrite symbiosis) and rich in rare earth minerals, the deposit has been a hot spot of ore deposit research. In this paper, taking the Wuding Yichang Fe-Cu rare earth deposit in central Yunnan as the research object, through field investigation, laboratory analysis and test, and comprehensive study of various geochemical means, the characteristics of mineral assemblage are summarized, and the original rock restoration of metamorphic surrounding rock is carried out. The trace elements, REE geochemical characteristics and elemental assemblage characteristics of metallic and nonmetallic minerals, as well as the characteristics of calcite Con O isotope and chalcopyrite S isotope, are studied, and the ore-forming materials and ore-forming fluid sources are summarized. The genesis of the deposit is discussed. The results show that: (1) the characteristics of mineral assemblage indicate that there is a close relationship between metallic minerals and non-metallic minerals in Yinnachang deposit. Magnetite, chalcopyrite are mostly symbiotic, with calcite, fluorite, There is also a symbiotic relationship between albite and other nonmetallic minerals. (2) the recovery of metamorphic primitive rocks: the metamorphic rocks of Yichang deposit are mainly sedimentary rocks (shale, mud shale) formed in the continental island arc environment. The geochemical characteristics of magnetite and pyrite elements in quartz sandstone (). (_ 3) indicate that the ore-forming material is not a simple magma source, but a variety of sources, and the local source may be a sedimentary source, which indicates that the ore-forming material may be a sedimentary alteration origin. The results show that the ore-forming fluid of Yinachang deposit is not a single source, the early magma genesis, and the late metamorphic hydrothermal superposition of ore-forming. (4) the Y/Ho-La/Ho diagram shows that the fluid may be the product of different stages of the same fluid system in different forms of fluorite in Nayinachang deposit; The third stage calcite has a relatively concentrated La/Ho and Y/Ho values indicating that they may form the same ore-forming fluid in a certain metallogenic stage. Fluorite, calcite are mainly hydrothermal origin. The geochemical study of rare earth elements in albite shows that albite is formed by hot water and hydrothermal fluid, and is hydrothermal albite. The metallogenic metal minerals are closely related to fluorite, calcite and albite. Therefore, Yinachang deposit is a typical hydrothermal deposit. Mantle fluid plays an important role in mineralization. (5) based on the Cno isotopic analysis of calcite in Yicheng Nachang deposit, it is concluded that most of the carbon in calcite is supplied by deep source carbon, which is influenced by precipitation and the mixed effect of sedimentary rocks. Some of the carbon in the calcite ore-forming fluid is derived from the dissolution of marine carbonate rocks, which indicates that the ore-forming hydrothermal fluid of Yinachang deposit is closely related to the deep magmatic fluid, and there is a mixture of deep magmatic water and atmospheric precipitation. The analysis of sulfur isotopes of chalcopyrite shows that the Yinachang deposit has the characteristics of IOCG deposit, the source of ore-forming fluid is closely related to mantle fluid, and it is related to the mixing of shallow crustal fluid and ore-forming material. (6) through symbiotic assemblage, It is preliminarily determined that Fe and Cu are synchronic ore-forming elements, U and REE are synchronic ore-forming elements. The main metallogenic period is about 1.6~1.7Ga, which is closely related to the extension of Kunyang rift and the splitting of Columbia supercontinent, which mainly forms iron and copper, and the second metallogenic stage is about 0.7~0.8Ga, which mainly shows the enrichment of uranium and rare earth.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P618.31;P618.41;P618.7

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