發(fā)布時間：2018-03-07 09:48

  本文選題：班公湖-怒江成礦帶　切入點：多龍礦集區(qū)　出處：《中國地質(zhì)大學(北京)》2017年博士論文　論文類型：學位論文

【摘要】：西藏多龍礦集區(qū)位于班-怒成礦帶西段北側(cè),發(fā)育西藏首個世界級的斑巖-高硫化型淺成低溫熱液型銅(金)礦床。為查明多龍礦集區(qū)成礦動力學背景,本文在前人工作的基礎(chǔ)上,以多龍礦集區(qū)色那礦區(qū)、外圍東窩東礦區(qū)含礦斑巖以及美日切錯組中酸性火山巖為研究重點,通過扎實的野外勘查工作,運用大量新的高精度測試分析與成礦理論,取得了以下的初步認識和成果:(1)提出東窩東礦區(qū)為多龍礦集區(qū)東延部分的新認識,獲得東窩東礦區(qū)含斑巖年齡為121.0~121.5Ma,色那礦區(qū)含礦斑巖年齡為118.1±1.4Ma,與多龍礦集區(qū)超大型-大型斑巖-淺成低溫熱液型-隱爆角礫巖型銅(金)礦床成巖成礦年齡115~125Ma相近,即早白堊世晚期的成巖成礦。(2)多龍礦集區(qū)東窩東、色那含礦斑巖屬鈣堿性-高鉀鈣堿性-鉀玄巖系列準鋁質(zhì)花崗巖,富集輕稀土和大離子親石元素,虧損重稀土及高場強元素;稀土元素分配曲線呈右傾平緩型,δEu呈現(xiàn)中等負異常到弱正異常,具備典型島弧巖漿巖特征。含礦斑巖具高(87Sr/86Sr)i值(0.0502~0.7111)、低的負εNd(t)值到低的正εNd(t)值(-7.7~+3.3);含礦斑巖εHf(t)為+0~+15.6,TDM C為176~1252 Ma;表明含礦斑巖是班-怒洋洋殼向北俯沖消減背景下,由玄武質(zhì)新生下地殼部分熔融形成的產(chǎn)物,源區(qū)內(nèi)可能有幔源物質(zhì)混入。(3)獲得美日切錯組流紋巖成巖年齡為109.3±2.2Ma,安山巖年齡為108.2±2.6Ma,與岡底斯地塊的大量早白堊世火山巖同期,其可能是班公湖-怒江洋殼發(fā)生雙向俯沖,洋殼出現(xiàn)了斷離(break-off)的產(chǎn)物。(4)美日切錯組火山巖屬高鉀鈣堿性-鉀玄巖系列巖石,富集輕稀土和大離子親石元素,虧損重稀土及高場強元素,δEu為0.65~0.80,(87Sr/86Sr)i值為0.7050~0.7053,εNd(t)值為-1.51~1.29;εHf(t)為+3.4~+15.5,TDM C為180~956Ma,表現(xiàn)出明顯的幔源特征,暗示美日切錯組火山巖是處于班-怒洋洋殼向北的俯沖背景下,由俯沖板片脫水產(chǎn)生流體交代地幔楔發(fā)生部分熔融形成原始玄武質(zhì)巖漿,并在上升滯留在殼幔邊界形成新生下地殼,新生下地殼與持續(xù)底侵幔源玄武質(zhì)巖漿混合而部分熔融形成。(5)提出多龍礦集區(qū)含礦斑巖及美日切錯組火山巖形成于典型活動大陸邊緣構(gòu)造背景的新認識,暗示班-怒洋盆在早白堊世晚期尚未關(guān)閉,洋盆仍正在向北俯沖于羌塘地塊之下,且108~109Ma時板片的俯沖角度變陡,拉薩地塊與羌塘地塊碰撞時間應晚于早白堊世晚期(108~109Ma)。
[Abstract]:The Dulong ore concentration area in Tibet is located on the northern side of the western section of the Ban-Nu metallogenic belt. The first world-class porphyry-high sulphide epithermal copper (gold) deposit was developed in Tibet. In order to find out the metallogenic dynamic background of the Dulong ore accumulation area, On the basis of previous work, this paper focuses on the ore bearing porphyry in the Xena mining area, the Dongwodong mining area in the periphery, and the intermediate and acid volcanic rocks of the United States and Japan Jieshi formation, through solid field exploration work. By using a large number of new high-precision test and metallogenic theories, the following preliminary understandings and results are obtained: (1) A new understanding that Dongwodong mining area is the east extension part of Dulong ore gathering area is put forward. The porphyry age of Dongwodong ore area is 121.0 ~ 121.5 Ma, and the porphyry age of Xena ore area is 118.1 鹵1.4 Ma, which is close to the diagenetic age of 115125 Ma in the extremely large and large porphyry type, epithermal type and cryptoexplosive breccia type copper (gold) deposit in the Dulong ore concentration area. That is, late early Cretaceous diagenesis and metallogenesis.) Donwodong ore concentration area, Xena ore-bearing porphyry belongs to calc-alkaline, high-potassium calc-alkaline-potash granites, enriched in light rare earth and large ion lithophile elements, depleted of heavy rare earth elements and high field strength elements. The distribution curve of rare earth elements is of the type of right dip flat, 未 EU shows moderate negative anomaly to weakly positive anomaly, The ore-bearing porphyry is characterized by typical island arc magmatic rocks. The ore-bearing porphyry is characterized by a high value of 87s r-86Sr ~ (-1) I (0.0502n / 0. 7111g), a low value of negative 蔚 Ndtt to a low value of positive 蔚 Ndtt (-7. 7 ~ 3. 3), and a porphyry porphyry with a TDM C of 0 ~ 15. 6 ~ 15.6 TDM C of 1761252 Maa, indicating that the ore-bearing porphyry was subducted northward in the Ban-Muyang oceanic crust, indicating that the ore-bearing porphyry was subducted in the northward subduction setting of the Ban-Muyang oceanic crust. From the partial melting of Black Tortoise's new lower crust, there may be mantle source materials mixed into the source area.) the diagenetic age of rhyolite in the United States and Japan is 109.3 鹵2.2 Ma. andesite age is 108.2 鹵2.6 Ma, which is at the same time as a large number of early Cretaceous volcanic rocks in the Gangdis block. It may be a bidirectional subduction of the Bangonghu and Nujiang oceanic crust, and a product of break-off in the oceanic crust. (4) the volcanic rocks of the United States and Japan fault formation belong to a series of high-potassium calc-alkaline-potacite series, which are rich in light rare earth elements and large ion lithophile elements. The loss of heavy rare earth elements and high field strength elements, 未 EU = 0.65 ~ 0.80 ~ (0.80) ~ (87) Sr _ (86) Sr ~ (-1) I = 0.7050 ~ 0.7053, 蔚 Ndt _ (t) = -1.51 ~ 1.29, 蔚 Hft) = 3.4- 15.5 ~ TDM _ (C) = 180 ~ 956 Ma. it is suggested that the volcanic rocks of the United States and Japan are located in the northward subduction background of the Ban-angyang oceanic crust, indicating that the volcanic rocks of the United States and Japan are under the background of northward subduction. The fluid metasomorphic mantle wedge was partially melted by dehydration of the subduction plate to form the primitive Black Tortoise magma, and then stayed at the crust-mantle boundary to form the new lower crust. A new understanding of the formation of ore-bearing porphyry in the Dulong ore concentration area and volcanic rocks of the United States and Japan in the typical active continental margin is proposed. It is suggested that the Ban-Nuyang basin was not closed in the late early Cretaceous, the oceanic basin was still subducting north under the Qiangtang block, and the subduction angle of the plate plate became steeper at 108109Ma. The collision time between Lhasa block and Qiangtang block should be later than that of the late Cretaceous.
【學位授予單位】：中國地質(zhì)大學(北京)
【學位級別】：博士
【學位授予年份】：2017
【分類號】：P612;P588.11

【相似文獻】

相關(guān)期刊論文 前4條

1 江少卿;孫興國;楊鐵錚;李麗;印賢波;王策;潘燕兵;;藏北多龍斑巖銅金礦集區(qū)綜合信息找礦模型研究[J];中國地質(zhì);2014年02期

2 代晶晶;曲曉明;;西藏多龍銅多金屬礦集區(qū)構(gòu)造及蝕變遙感信息提取[J];地質(zhì)與勘探;2012年04期

3 林川;;金屬活動態(tài)提取技術(shù)在多龍銅礦區(qū)的應用[J];中國科技信息;2014年Z1期

4 方向;唐菊興;李彥波;王勤;丁帥;張志;楊超;李玉彬;陳紅旗;衛(wèi)魯杰;尼瑪;;西藏多龍礦集區(qū)拿若銅(金)礦床成礦元素空間分布規(guī)律及地球化學勘查模型[J];中國地質(zhì);2014年03期

相關(guān)博士學位論文 前2條

1 韋少港;西藏班-怒成礦帶多龍礦集區(qū)早白堊世巖漿作用及動力學背景[D];中國地質(zhì)大學(北京);2017年

2 孫振明;西藏班—怒成礦帶西段多龍礦集區(qū)銅金成礦作用與成礦規(guī)律[D];吉林大學;2015年

相關(guān)碩士學位論文 前5條

1 李興奎;西藏多龍超大型銅金礦巖漿起源與成礦大地構(gòu)造背景[D];吉林大學;2016年

2 汪傲;西藏多龍礦集區(qū)西南部典型礦床成因研究[D];中國地質(zhì)大學(北京);2016年

3 白榮龍;西藏多龍礦集區(qū)巖漿巖地球化學特征及成因研究[D];成都理工大學;2016年

4 方剛;青海省興�？h什多龍鉛鋅礦床地質(zhì)特征及找礦前景分析[D];中國地質(zhì)大學（北京）;2013年

5 胡紫豪;西藏多龍斑巖型銅金礦預測工作區(qū)多元信息找礦預測[D];成都理工大學;2012年

，

本文編號：1578932