本文選題：斑巖銅金礦 + 巖漿巖成因　； 參考：《巖石學(xué)報(bào)》2017年10期

【摘要】：西藏多龍礦集區(qū)(包括多不雜、波龍、拿若和鐵格隆南(榮那)四個(gè)大型-超大型斑巖型-淺成低溫?zé)嵋盒豌~金礦床)位于班公湖-怒江縫合帶西段,目前已探明銅的資源量超過(guò)1600萬(wàn)噸,金大于200噸。班公湖-怒江縫合帶的找礦勘查工作現(xiàn)在正處于起步階段,本文以多龍礦集區(qū)為例,系統(tǒng)討論了該礦集區(qū)與成礦作用相關(guān)的巖漿巖的成因、成巖與成礦作用的相互關(guān)系并初步提出了針對(duì)該縫合帶斑巖銅金礦床的找礦勘查步驟和標(biāo)志。全巖地球化學(xué)、Sr-Nd-Hf同位素、造巖礦物化學(xué)成分等實(shí)驗(yàn)結(jié)果表明多龍地區(qū)與成礦作用相關(guān)的巖漿巖形成于殼�；旌献饔貌橛懈_沉積物的加入,巖漿在演化過(guò)程中還經(jīng)歷了一定程度的結(jié)晶分異作用和基性巖漿的注入并最終侵位至地殼淺部或噴發(fā)出地表。研究表明成礦物質(zhì)主要來(lái)自于地幔源區(qū),隨后金屬元素在富水(≥4%H_2O)和較高氧逸度(ΔNNO0.5)的巖漿環(huán)境下運(yùn)移至地殼上部(距地表2.5~7.5km)巖漿房中,由于成礦物質(zhì)(Cu、Au和H_2O)在中酸性巖漿中的溶解度隨溫度壓力降低而降低,因此侵位較淺的巖漿房更容易發(fā)生含礦流體的出溶并最終形成斑巖銅金礦。研究提出班公湖-怒江縫合帶斑巖型銅金礦的找礦勘查工作可按以下步驟和找礦標(biāo)志來(lái)進(jìn)行:(1)通過(guò)Nd、Hf同位素填圖確認(rèn)地幔組分相對(duì)較多的侵入巖分布區(qū)為成礦遠(yuǎn)景區(qū),該區(qū)域巖石學(xué)特征可能表現(xiàn)為暗色包體(MMEs)大量發(fā)育;(2)通過(guò)角閃石、鋯石等礦物開(kāi)展氧逸度填圖進(jìn)一步圈定重點(diǎn)找礦勘查區(qū),巖漿巖中角閃石的發(fā)育往往預(yù)示著較好的成礦潛力;(3)在重點(diǎn)找礦勘查區(qū)內(nèi)通過(guò)巖漿磁鐵礦中V、Ti含量對(duì)斑巖體的含礦性進(jìn)行快速判定,具有較低V、Ti含量的斑巖體通常為含礦性較好的斑巖體。此外,富水(角閃石發(fā)育)、含礦質(zhì)(黃銅礦呈他形晶粒狀產(chǎn)出)、侵位淺(氣相包裹體與多相包裹體共同產(chǎn)出)、并有蝕變礦物(次生黑云母、綠泥石)發(fā)育的中酸性巖體也可指示較好的成礦潛力。
[Abstract]:The Dulong ore concentration area in Tibet (including Dobonghu, Polong, Naro and Tigrongnan (Ronna), four large, super-large porphyry and epithermal hydrothermal copper-gold deposits) is located in the western section of the Bangong Lake-Nujiang suture zone. At present, the amount of proven copper resources is more than 16 million tons, and gold is more than 200 tons. The prospecting and exploration of the Bangonghu-Nujiang suture zone is now in its infancy. Taking the Dulong ore accumulation area as an example, the genesis of the magmatic rocks related to the mineralization in the ore concentration area is discussed systematically in this paper. The interrelation between diagenesis and metallogenesis and the prospecting steps and marks for porphyry copper-gold deposit in this suture zone are put forward preliminarily. The experimental results of Sr-Nd-Hf isotopes and petrogenic mineral chemical compositions indicate that magmatic rocks related to mineralization in the Dulong area were formed in crust-mantle mixing with the addition of subduction sediments. The magma also experienced some crystallization differentiation and the injection of basic magma during the evolution process and finally emplaced to the shallow part of the crust or erupt out of the earth's surface. The results show that the ore-forming material mainly comes from the mantle source region, and then the metallic elements migrate to the magma chamber of the upper crust (2.5 ~ 7.5km from the surface) under the magmatic environment of rich water (鈮，

本文編號(hào)：1788129