發(fā)布時(shí)間：2018-04-15 08:39

  本文選題：石英脈-蝕變巖型金礦 + 垂直分帶�。� 參考：《成都理工大學(xué)》2015年碩士論文

【摘要】：大渡河金成礦帶位于康滇地軸南北向構(gòu)造帶北端,鮮水河、龍門(mén)山與攀西裂谷所構(gòu)成的三叉裂谷交會(huì)形成的特殊構(gòu)造部位,是我國(guó)西南地區(qū)重要的一個(gè)金成礦帶。該區(qū)域上受北部的華北板塊、東部的揚(yáng)子板塊及西部的印度板塊這3個(gè)不同方位的板塊相互之間的俯沖、碰撞及陸內(nèi)會(huì)聚而形成一個(gè)倒三角,區(qū)內(nèi)構(gòu)造復(fù)雜,褶皺、斷裂十分發(fā)育,受南北向與東西向雙向擠壓。在板塊俯沖、碰撞過(guò)程中發(fā)育大量的韌性剪切帶,而許多韌性帶中分布著大量的長(zhǎng)英質(zhì)脈、石英脈。正是這些大型韌性推覆構(gòu)造形成大量層內(nèi)與層間滑脫的儲(chǔ)礦空間,變質(zhì)變形作用強(qiáng)烈,為本區(qū)域金成礦創(chuàng)造了極為有利的地質(zhì)背景和成礦條件。在該區(qū)域南北長(zhǎng)60km、東西寬幾千米至30km范圍內(nèi),已發(fā)現(xiàn)巖金礦床(點(diǎn))60余處,構(gòu)成了著名的康定大渡河“金谷”。白金臺(tái)子礦床是該區(qū)域內(nèi)比較具有代表性的礦床,它位于康定縣境內(nèi),屬于三合鄉(xiāng)管轄,礦體產(chǎn)于康定雜巖推覆體內(nèi)部。自從該礦床開(kāi)采利用以來(lái),對(duì)礦床深部是否有礦尚未進(jìn)行探討。本文選擇該礦床作為研究對(duì)象,重點(diǎn)研究該礦床的垂直分帶規(guī)律,探討礦床成因,為深部預(yù)測(cè)性找礦提供參考。本文主要研究?jī)?nèi)容包括:區(qū)域地質(zhì)背景、區(qū)域巖漿巖特征、礦床地質(zhì)特征、礦床地球化學(xué)特征、元素垂直分帶規(guī)律等。通過(guò)以上研究,取得如下成果和認(rèn)識(shí):(1)礦床圍巖主要為咱里組混合花崗巖。其特點(diǎn)為,輕稀土較重稀土富集,內(nèi)部分餾明顯,弱負(fù)銪異常,這種特征是在地殼增厚條件下,為硅鋁層重熔成因的異地型巖漿侵入花崗巖所特有的稀土元素分布特征。(2)礦體的產(chǎn)狀在空間上產(chǎn)狀變化為上緩下陡,呈膝狀,礦床的賦礦巖石主要為花崗巖,主要載金礦物為黃鐵礦和石英。(3)礦床圍巖蝕變類型主要有硅化、黃鐵礦化、絹云母化、綠泥石化、碳酸鹽化、簾石化等。這些圍巖蝕變產(chǎn)物具有明顯的垂直分帶現(xiàn)象。在礦床上部,主要以硅化、黃鐵礦化為主;在床下部,主要以硅化、黃鐵礦化、黃銅礦化、方鉛礦礦化、碳酸鹽化為主。(4)礦床中元素在垂直空間上呈現(xiàn)一定的分帶性:在礦床下部石英的微量元素含量要比上部的高,即說(shuō)明上部的石英要較純些;黃鐵礦中Cu、Pb、Bi含量及Pb/Sb從上往下逐漸升高,而Li、Co、Ni、Sr、Mo、Ba,Co/Ni明顯降低;石英中Zn、Pb、Ni、Ba、Sb、Sr含量及Pb/Sb自上往下逐漸升高,而Cu、Li、Sr、Mo,Co/Ni和Mo/Bi明顯降低,Be、Cd、W、Bi等元素含量變化不大。(5)白金臺(tái)子石英脈中黃鐵礦硫同位素分析結(jié)果δ34S值為0.7‰~1.1‰,均值為0.97‰,均一化程度較高,分布集中,接近隕石硫,具明顯的巖漿硫或幔源硫同位素組成特點(diǎn)。說(shuō)明礦體中硫來(lái)源于深部巖漿,預(yù)示著金成礦與巖漿熱液有密切的關(guān)系。(6)礦區(qū)內(nèi)基性輝綠巖脈與含金石英緊密相伴。輝綠巖的鋯石U-Pb年齡為425.3士3.1Ma,而含礦石英的形成年齡為32.4~43Ma,平均為37.7Ma。二者形成時(shí)代明顯不一致,成礦時(shí)代大大晚于基性脈巖的形成。但這些基性巖脈(體)的出現(xiàn)指示了其所在位置曾發(fā)生過(guò)深達(dá)下地殼或上地幔的拉張作用,說(shuō)明大渡河斷裂是深達(dá)下地殼或上地幔的深大斷裂。在區(qū)域性拉張的環(huán)境下,不僅有利于深部地殼或上地幔的基性巖漿的上升侵位,同樣有利于深部熱液流體的運(yùn)移。
[Abstract]:The Dadu River gold metallogenic belt is located in the Kangdian axis north-south tectonic belt at the north end, fresh water river, special tectonic location of Longmen mountain and the Panxi rift formed by the intersection of trigeminal rift formation, is a Southwest important gold metallogenic belts in China. The area affected by the north of the North China plate, the eastern part of the Yangtze plate and the western India plate of the 3 different directions between plate subduction, collision and intracontinental convergence and the formation of an inverted triangle area, complex structures, folds, faults are well developed, the north-south and east-west two-way extrusion. In the subduction zone, ductile shear zone for the development of a large number of collision process, and a lot of ductile zone distributed in felsic veins, a quartz vein. It is these large ductile nappe structure formed in a large number of coal storage space layer and interlayer slip, strong metamorphism and deformation, the regional gold mineralization has created extremely favorable. Background and metallogenic conditions in the region. 60km long from north to south, east-west width of several thousand meters to the range of 30km, has been found in rock gold deposits (points) 60, a famous Kangding Dadu River "Valley". The platinum deposit is the region table more representative of the deposit, which is located in Kangding County three, belonging to the township jurisdiction, ore produced in the Kangding complex nappe. Since the deposit exploitation is not discussed in deep ore deposit. The ore deposit as the research object, focuses on the vertical zoning of the deposit, the genesis for deep forecast for mine for reference. The main contents of this paper include: regional geological background, regional magmatite features, geological characteristics, geochemical characteristics of the deposit, the elements of vertical zoning. Through the above research, the following results and understanding: (1) the main rock deposit I was in group. The characteristics of mixed granite, light rare earth heavy REE enrichment, internal fractionation significantly, weak negative Eu anomaly, which is characterized by thickening of the crust under the condition of invasion of rare earth elements peculiar to different type granite magma remelting sial origin distribution. (2) the occurrence of orebody the shape change in space to slow down a steep, geniculate, ore bearing rock deposits are mainly granite, the main gold bearing minerals are pyrite and quartz. (3) deposit types of wall rock alteration includes silicification, pyritization, sericitization, chloritization and epidotization carbonate, etc. these. The wall rock alteration product has obvious vertical zonation phenomenon. In the upper part of the deposit, mainly silicification, pyritization; in the lower part of the bed, mainly silicification, pyrite, chalcopyrite, galena mineralization, carbonate deposits. (4) in element in the vertical space presents certain points 甯︽，

本文編號(hào)：1753397