本文關(guān)鍵詞： 包古圖 宏遠(yuǎn) 還原性斑巖銅礦 構(gòu)造背景 形成機(jī)制　出處：《中國(guó)地質(zhì)大學(xué)(北京)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：自Rowins(2000)首次提出還原性斑巖銅礦(RPCDs)以來(lái),這類以發(fā)育大量巖漿階段磁黃鐵礦和成礦流體富CH4為主要特征、與鈦鐵礦系列花崗質(zhì)巖石存在成因聯(lián)系、礦化和蝕變規(guī)模較小的斑巖礦床在世界范圍內(nèi)不斷被發(fā)現(xiàn)并引起越來(lái)越多的學(xué)者關(guān)注。近期研究發(fā)現(xiàn),西準(zhǔn)南部地區(qū)的包古圖銅礦與宏遠(yuǎn)鉬銅礦具有還原性斑巖礦床特征。然而,關(guān)于這兩個(gè)礦床構(gòu)造背景與成因機(jī)制的認(rèn)識(shí)還存在爭(zhēng)論,同時(shí),關(guān)于西準(zhǔn)南部地區(qū)構(gòu)造單元屬性與演化過(guò)程的認(rèn)識(shí)也具有較大分歧。本文以西準(zhǔn)南部地區(qū)構(gòu)造演化、以及包古圖與宏遠(yuǎn)斑巖礦床形成機(jī)制為主要研究對(duì)象,通過(guò)大量的野外地質(zhì)調(diào)查與室內(nèi)實(shí)驗(yàn)測(cè)試分析,結(jié)合前人研究成果,獲得以下研究進(jìn)展:(1)劃分西準(zhǔn)地區(qū)構(gòu)造單元,以謝米斯臺(tái)斷裂為界分為南北兩部分,六個(gè)構(gòu)造單元,北部西準(zhǔn)包括:薩吾爾大洋島弧與謝米斯臺(tái)弧,南部西準(zhǔn)包括:巴爾魯克弧、洋殼俯沖增生雜巖帶、包古圖弧與拉巴地體;(2)提出巴爾魯克早泥盆-晚石炭世陸緣弧、拉巴晚奧陶-中志留世陸緣弧與包古圖石炭紀(jì)大陸島弧,并限定這三個(gè)弧的俯沖結(jié)束時(shí)間分別為302Ma,410Ma與321Ma;(3)在包古圖礦區(qū)識(shí)別出富銅輝長(zhǎng)巖,指出基性巖漿對(duì)礦區(qū)成礦具重要貢獻(xiàn);(4)建立了宏遠(yuǎn)礦區(qū)蝕變與礦化分帶結(jié)構(gòu),發(fā)現(xiàn)富黃銅礦與磁黃鐵礦巖漿-流體囊,指出宏遠(yuǎn)礦床為新型還原性性斑巖鉬銅礦,成礦作用經(jīng)歷了晚期巖漿-熱液階段(400~440℃)流體氧化還原環(huán)境發(fā)生突變成礦、及熱液階段(160~200℃)降溫、降壓成礦;(5)建立西準(zhǔn)南部地區(qū)構(gòu)造演化與成礦模型,指出后碰撞階段加厚下地殼拆沉-軟流圈地幔上涌與基性巖漿的參與,是形成還原性斑巖銅鉬礦的重要條件。
[Abstract]:Since Rowins2000 first proposed the reductive porphyry copper deposit (RPCDs), this type is mainly characterized by the development of a large number of magmatic stage pyrrhotite and the rich CH4 of ore-forming fluids. The porphyry deposits with small mineralization and alteration scale have been found in the world and attracted more and more scholars' attention. The Baogutu copper deposit and Hongyuan molybdenum copper deposit in the southern part of West China are characterized by reductive porphyry deposits. However, the understanding of the tectonic background and genetic mechanism of the two deposits is still controversial and at the same time. There are also differences on the attributes and evolution process of tectonic units in the southern part of the western part of China. The tectonic evolution in the west of the region and the formation mechanism of the Baogutu and Hongyuan porphyry deposits are the main objects of study. Through a large number of field geological surveys and laboratory test and analysis, combined with the previous research results, the following research progress was obtained: 1) dividing the structural units in the West area into two parts, which are divided into two parts: the Shemis platform fault as the boundary and the north and south parts as the boundary. Six tectonic units, including the Sawuer oceanic island arc and the Schaemis platform arc to the north, and the Baluk arc to the south, the oceanic crust subducting accretive complex belt, the Baogutu arc and the Raba terrane to the west; (2) the early Devonian and late Carboniferous continental margin arc in Balluk, the late Ordovician margin arc in Raba and the Carboniferous continental island arc in Baogutu are proposed, and the subduction ending time of these three arcs is defined as 302Ma. 410Ma and 321Ma; (3) the copper-rich gabbro is identified in Baogutu ore area, and it is pointed out that the basic magma has an important contribution to the ore-forming of the ore area. (4) the alteration and mineralization zonation structure of Hongyuan ore area has been established, and the rich chalcopyrite and pyrrhotite magma fluid sac have been found. It is pointed out that the Hongyuan deposit is a new type of reductive porphyry molybdenum copper deposit. The ore-forming process experienced the late magmatic hydrothermal stage (400 ~ 440 鈩，

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