【摘要】：哈西亞圖鐵多金屬礦床位于東昆侖西段祁漫塔格地區(qū),是區(qū)域典型的層控矽卡巖礦床,也是近年來首例在金水口巖群中發(fā)現(xiàn)的與中酸性巖體有關的矽卡巖礦床,目前鐵、金、鋅已達中型,進一步找礦潛力巨大。本文利用巖石學、礦物學、地質年代學、巖石地球化學等研究手段,結合前人研究成果,針對東昆侖祁漫塔格地區(qū)三疊紀地球深部動力學與矽卡巖成礦作用提出了新的認識,在此基礎上對哈西亞圖礦床進行了剖析,并結合同時期大地構造背景建立了成礦模式,同時通過對比地層建造與巖漿巖性質,論述了哈西亞圖礦床與區(qū)內(nèi)其他矽卡巖礦床的異同點,拓寬了區(qū)域找礦思路。通過研究取得以下認識:1.通過對搜集到的784個火成巖同位素年齡數(shù)據(jù)分布特征與地質演化過程對比研究,認為:受古特提斯殘留洋盆(阿尼瑪卿洋盆)閉合作用影響,俯沖與碰撞作用在東昆侖地區(qū)影響廣泛,集中表現(xiàn)在印支期巖漿活動極為強烈,與之對應的矽卡巖成礦事實多,表明:印支期俯沖碰撞作用可以為該區(qū)矽卡巖成礦提供良好的地質背景條件。同時,區(qū)域同時期含暗色微粒包體花崗質巖石是幔源巖漿經(jīng)歷多個MASH(Melting Assimilation Storage Homo-genization,即:熔融—同化—存儲—均一)過程后與殼源巖漿混合的結果,在混合巖漿中,富鎂鐵質端元是由輝長質巖漿進化而來的閃長質巖漿,在此過程中富鎂鐵質端元由于來源較深,因而混合巖漿中富集鐵、金等元素,為本區(qū)矽卡巖成礦提供了充足的幔源金屬礦物。2.哈西亞圖礦床中礦體呈層狀、似層狀產(chǎn)出,礦體總體沿地層產(chǎn)狀順層產(chǎn)出;礦石結構構造類型多樣,主要有半自形粒狀結構、不規(guī)則狀結構、交代結構、包含結構,構造有塊狀、稠密浸染狀構造、浸染狀構造、星散狀—星點狀構造、條帶狀構造;圍巖蝕變類型主要有:矽卡巖化、硅化、綠泥石化、綠簾石化、碳酸鹽化等。根據(jù)矽卡巖分布情況大致以3號勘探線為中心,向西及向東分為石榴子石矽卡巖帶、透輝石矽卡巖帶、綠簾石矽卡巖帶、陽起石矽卡巖帶、透閃石矽卡巖帶等。3.通過精確LA—ICP—MS同位素測年工作,獲得礦床石英閃長巖成巖時代為246.8±1.8Ma,礦區(qū)外圍花崗閃長巖年齡為240.1±0.8Ma。表明哈西亞圖礦床形成于早三疊世。磁鐵礦的δ18O值介于2.7‰~4.1‰,表明成礦流體中除了巖漿水外,還有大氣降水。黃鐵礦與閃鋅礦δ34S值為4.63‰~6.30‰,總硫值為3.77‰,說明礦區(qū)硫來源于殼�；旌蠋r漿,并有地殼物質混入。黃鐵礦鉛同位素變化較小(208Pb/204Pb、207Pb/204Pb、206Pb/204Pb分別為38.471~38.629、15.627~15.671和18.435~18.473),同樣顯示出殼�；旌铣梢蛱攸c,此外,地層建造也為成礦提供了豐富的鐵質。4.根據(jù)礦床地質特征認為成礦要素包括:(1)礦區(qū)片麻巖類與大理巖的脆性接觸帶,同時大理巖具備諸多有利于矽卡巖化作用的發(fā)生的先決條件。(2)礦區(qū)NE向斷裂與東昆侖區(qū)域性大斷裂關系密切,可能是區(qū)域性斷裂引發(fā)的小型次級斷裂,但切割深度較深。(3)礦區(qū)具殼�；旌铣梢虻氖㈤W長巖產(chǎn)出部位距礦體較遠,為巖體淺成侵位后從地層中攝取鐵質提供足夠的空間與時間。結合同時期大地構造背景認為礦床成礦模式如下:在經(jīng)歷俯沖作用之后,殼幔源巖漿在深部熔融并混合,在巖漿侵位間隙大氣降水或地層同生水沿昆中大斷裂誘發(fā)的次級斷裂帶下滲,與此同時,從地層中淋濾出金屬物質并與石英閃長巖再次發(fā)生混合形成成礦流體。受壓力差作用影響,成礦流體沿裂隙面上升,遇到這些因機械性質不同而性質脆弱的地層界面后,引發(fā)含礦熱液順層交代碳酸鹽巖,形成矽卡巖,同時形成早期的磁鐵礦體,矽卡巖期后酸性淋濾階段形成金屬硫化物、自然金等。哈西亞圖鐵多金屬矽卡巖礦床雖然具有典型矽卡巖礦床分帶性、交代反應等特征,但更符合層控矽卡巖礦床定義,通過研究,本文認為哈西亞圖鐵多金屬礦床成因屬層控矽卡巖礦床成因類型。
[Abstract]:The Hasitu iron polymetallic deposit is located in the Qimantag area of the western section of East Kunlun Mountains. It is a typical stratabound skarn deposit in the region. It is also the first skarn deposit related to intermediate-acidic rock mass discovered in Jinshuikou rock group in recent years. At present, iron, gold and zinc have reached medium-sized and have great potential for further prospecting. Geochronology, petrogeochemistry and other research methods, combined with predecessors'research results, put forward a new understanding of the Triassic geodynamics and skarn mineralization in the Qimantag area of East Kunlun Mountains. On this basis, the Hashiatu deposit was analyzed, and the metallogenic model was established in combination with the geotectonic setting of the same period. By comparing the stratigraphic formation and magmatic rock properties, this paper discusses the similarities and differences between the Hashiatu deposit and other skarn deposits in the area, and broadens the regional prospecting ideas. The following understandings are obtained through the study: 1. By comparing the distribution characteristics of 784 igneous rock isotope age data collected and the geological evolution process, it is believed that the Hashiatu deposit was subjected to Paleo-Tethys. The closure of residual oceanic basin (Animaqing oceanic basin) is influenced by subduction and collision widely in East Kunlun area. The intensive magmatism in Indosinian period is the main manifestation. There are many related skarn mineralization facts, which indicate that the Indosinian subduction and collision can provide favorable geological background for skarn mineralization in this area. The dark-grained xenoliths in the same period are the result of the mixing of mantle-derived magma with crustal-derived magma after several MASH (Melting-Assimilation Storage Homo-genization, i.e. melting-assimilation-storage-homogenization) processes. In the migmatitic magma, the mafic-rich end-member is dioritic magma evolved from gabbro magma. In this process, the mafic-rich end-members are rich in iron, gold and other elements in the migmatite magma, which provides abundant mantle-derived metallic minerals for skarn mineralization in this area. 2. The ore bodies in the Hashiatu deposit are stratified and occur like layers, and the ore bodies generally occur along the strata, and the ore structures are various, mainly semi-automorphic. Granular structure, irregular structure, metasomatic structure, including structure, structure block, dense disseminated structure, disseminated structure, star scattered-star structure, strip structure; wall rock alteration types are mainly skarnization, silicification, chloritization, epidote, carbonation and so on. The center is divided westward and eastward into garnet skarn belt, diopside skarn belt, epidote skarn belt, manolite skarn belt, tremolite skarn belt and so on. 3. Through accurate LA-ICP-MS isotope dating, the diagenetic age of quartz diorite in the deposit is 246.8 (?) 1.8 Ma, and the age of granodiorite in the periphery of the deposit is 240.1 (?) 0.8 Ma. It is indicated that the Hashiatu deposit was formed in the Early Triassic. The value of ~4.182 The minor element variations (208 Pb/204 Pb, 207 Pb/204 Pb, 206 Pb/204 Pb, 38.471-38.629, 15.627-15.671 and 18.435-18.473, respectively) also show the characteristics of crust-mantle mixing genesis. In addition, the strata also provide abundant iron for mineralization. 4. According to the geological characteristics of the deposit, the metallogenic elements include: (1) brittle connection between gneiss and marble in the ore area. The NE-trending faults in the mining area are closely related to the regional large faults in East Kunlun, which may be small secondary faults caused by regional faults, but the cutting depth is deeper. (3) The occurrence of crust-mantle mixed quartz diorite in the mining area is far from the orebody. Combined with the geotectonic setting of the same period, the metallogenic model of the deposit is as follows: after subduction, the crust-mantle magma melts and mixes in depth, and the secondary faults induced by atmospheric precipitation or strata associated water along the Kunzhong fault occur between the magmatic emplacement intervals. At the same time, metals leached from the strata and mixed with quartz diorite again to form ore-forming fluids. Influenced by pressure difference, ore-forming fluids rise along the fracture surface. When these strata are fragile due to different mechanical properties, the ore-bearing hydrothermal metasomatism along the carbonate rocks, forming skarns. At the same time, early magnetite bodies were formed, and metal sulfides and natural gold were formed in the post-skarn acid leaching stage. Although the Hashiatu iron polymetallic skarn deposit has the characteristics of typical skarn deposit zoning and metasomatic reaction, it is more in line with the definition of stratabound skarn deposit. Bed formation is a genetic type of stratabound skarn deposit.
【學位授予單位】：長安大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：P618.2

【參考文獻】

相關期刊論文 前10條

1 劉建朝;張海東;劉淑文;戈小紅;;太行山南段平順地區(qū)雜巖體成因研究[J];地質論評;2009年03期

2 莫宣學;羅照華;鄧晉福;喻學惠;劉成東;諶宏偉;袁萬明;劉云華;;東昆侖造山帶花崗巖及地殼生長[J];高校地質學報;2007年03期

3 王德滋;謝磊;;巖漿混合作用:來自巖石包體的證據(jù)[J];高校地質學報;2008年01期

4 于淼;豐成友;趙一鳴;李大新;肖曄;劉建楠;李澤峰;;青�？ǘ鴧s卡銅多金屬礦床流體包裹體地球化學及成因意義[J];地質學報;2014年05期

5 陳臻;;銅山嶺“層間矽卡巖型”多金屬礦床成因探討[J];礦床地質;1986年02期

6 崔彬;;銅官山層控矽卡巖型銅礦床的蝕變分帶及其成因[J];礦床地質;1987年01期

7 趙一鳴;夕卡巖礦床研究的某些重要新進展[J];礦床地質;2002年02期

8 徐林剛;毛景文;楊富全;葉會壽;鄭建民;李建國;蔡永彪;查小玲;高建京;;新疆蒙庫鐵礦床矽卡巖礦物學特征及其意義[J];礦床地質;2007年04期

9 溫泉;溫春齊;黃于鑒;;基于Excel的金屬礦床中總硫同位素計算與繪圖[J];科技通報;2012年04期

10 陳能松,何蕾,王國燦,張克信,孫敏;東昆侖造山帶早古生代變質峰期和逆沖構造變形年代的精確限定[J];科學通報;2002年08期

相關博士學位論文 前1條

1 徐國端;青海祁漫塔格多金屬成礦帶典型礦床地質地球化學研究[D];昆明理工大學;2010年

，

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