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5)需要補充說明,白乃廟大型金礦床(伴銅)位于白乃廟銅金礦床以北約2km處,該礦圍巖同樣是白乃廟群,容礦韌性剪切帶與白乃廟銅金礦床南礦帶的容礦斷裂幾乎平行、性質相似,礦床地質地球化學特征(Meng et al,1995;李進文等,2003)與造山型金礦(倪培等,2000;范宏瑞等,2000,2003;陳衍景等,2004;Kerrich等,2000)類似,成礦作用發(fā)生在“造山作用進入陸內演化階段,區(qū)域構造體制發(fā)生轉換后的伸展環(huán)境”(李進文等,2003)。根據前述,結合申請人與Phelps Dodge公司郭景峰等3位地質師、日本株友集團地質學家高崗俊秀教授、北京大學陳衍景教授的聯(lián)合野外考察和討論,認為白乃廟銅金礦床與世界上已報道銅礦類型(斑巖型、矽卡巖型、淺成低溫熱液型、砂巖型、鐵氧化物型、VMS/VHMS型等)均有顯著不同,與造山型金礦相似,具有重要研究價值和勘探意義,但現(xiàn)存如下薄弱環(huán)節(jié)或問題:(1) 關于礦床類型的認識分歧嚴重,僅聶風軍(1993,1994,2004)一人,就先后提出了3種不同認識,足見礦床地質特征特殊,類型歸屬不清。根本原因是,前人重視了礦床同位素地球化學研究,忽視了礦床地質研究,而礦床地質特征才是決定礦床類型的最關鍵依據。(2)除聶風軍等(1993)獲得部分流體包裹體均一溫度之外,以流體包裹體為主的成礦流體系統(tǒng)研究極為薄弱,缺乏界定流體系統(tǒng)類型所必須的包裹體組合特征以及流體鹽度、壓力、成分等參數(shù),流體系統(tǒng)的演化更無從談起。因此,目前關于巖漿熱液、大氣降水、海底噴流等成礦觀點均無說服力,難免爭論不休。(3)成礦年代學研究近乎空白,致使成礦時間不明,學者們有海底噴流(或VMS)、變質改造、巖漿熱液(或斑巖型)、多期成礦等多種推論。聶鳳軍等(1994,1995)將北礦帶賦礦花崗閃長斑巖SmNd等時線年齡(440Ma)作為白乃廟銅礦成礦時間,不符合成礦晚于圍巖的科學邏輯。而和鐘鏵等(2001)報道該花崗閃長斑巖的成巖年齡為397 Ma。(4)世界大型、超大型銅礦多為斑巖型、VMS型等,主要形成于板塊離散或巖漿弧環(huán)境。因此,我國學者總傾向于將白乃廟銅金礦床劃歸斑巖型或VMS型,學術思路被局限,忽視了白乃廟礦床自身的地質特征和研究區(qū)構造演化的特征。例如,礦部門口矗立著白乃廟銅金礦床的標志性礦石(見照片A和B),可見其礦石礦物(黃鐵礦、黃鐵礦、方鉛礦等)充填膠結已經變形破碎的乳白色石英脈角礫,并被未變形的晚階段石英碳酸鹽細脈穿切,不僅顯示了與造山型金礦系統(tǒng)(范宏瑞等,2000;李晶等,2004)的相似性,而且與斑巖型和VMS型銅礦的特征截然不同。此外,該特征還指示成礦作用發(fā)生在由擠壓變形(早階段破碎石英脈)經剪切向伸展穩(wěn)定環(huán)境轉變的構造體制,成礦后研究區(qū)再未經歷強烈的構造變形,即應發(fā)生在陸陸碰撞向陸內演化的過程。總之,選擇地質特征復雜的白乃廟大型銅金礦床為解剖對象,在扎實的礦區(qū)和礦床野外工作基礎上,詳細開展礦相學、巖相學和成礦年代學研究,確定成礦與研究區(qū)構造演化的時間耦合關系,從而準確厘定礦床成因類型,建立成礦模式,不僅符合學科發(fā)展趨勢,檢驗CMF模式的適用性,甄別已有成因觀點,而且可以突出白乃廟礦床的地質特色,有可能率先提供造山型銅礦的研究實例,從而為成礦理論發(fā)展,拓寬研究區(qū)銅金礦床找礦思路,做出實際貢獻。主要參考文獻Chen Yanjing, 1997. Mineralization during collisional orogenesis and its control of the distribution of gold deposits in Junggar mountains, Xinjiang, China. Acta Geologica Sinica, 71, 6979.Chen Y J, Pirajno F, Sui Y H, 2004. Isotope geochemistry of the Tieluping silver deposit, Henan, China: A case study of orogenic silver deposits and related tectonic setting. Mineralium Deposita, 39, 560575.Goldfarb R J, Groves D I, Cardoll S, 2001. Orogenic gold deposits: a global synthesis. Ore Geology Review, 18: 175.Goldfarb R J, et al., 2003. Tectonic and metallogenic evolution of the Altay Shan, Northern Xinjiang Uygur Autonomous region, northernwestern China. Tectonic Evolution and Metallogeny of the Chinese Altay and Tianshan, Natural History Museum, London, 1730.Groves D I, Goldfarb R J,GebreMariam, et al, 1998. Orogenic gold deposits: A proposed classification in the context of their crustal distribution and relationship to other gold deposit types. Ore Geology Reviews,13: 727.Haeberlin Y, Moritz R, Fontbote L, et al,2003. Paleozoic orogenic gold deposits in the eastern Central Andes and its foreland, South America. Ore Geology Reviews,22, 4159.Hart C J R, Goldfarb R J, Qiu Y M, et al. , 2002. Gold deposits of the northern margin of the North China Craton: multiple late PaleozoicMesozoic mineralizing events. Mineralium Deposita,37: 326351. Hong D, Wang S, Xie, Zhang J, Wang T, 2003. Granitoids and related metallogeny of Centrl Asian Orogenic Belt. Tectonic Evolution and Metallogeny of the Chinese Altay and Tianshan, Natural History Museum, London, 3174.Kerrich R, 1999. Nature’s gold factory. Science, 284, 21012102. Kerrich R, Goldfarb R, Groves D, et al. characteristics, origins and geodynamic settings of supergiant gold metallogenic provinces. Science in China Series D, 43(supp): 168.Mao J W, Konopelko D, Seltmann R, Lehmann B, Chen W, Wang Y T, Eklund O, Usubaliev T, 2004. Postcollisional Age of the Kumtor Gold Deposit and Timing of Hercynian Events in the Tien Shan, Kyrgyzstan. Economic Geology, 99, 1771–1780Meng L Y, Zhu T T, Zhou L H. 1995. Oreforming information of quartz veintype gold deposits-Taking Bainaimiao gold deposit. Science in China, 38(4): 495503.Nie F J, Jiang S H, Su X X, Wang X L, 2002. Geological features and origin of gold deposits occurring in the Baotou–Bayan Obo district, southcentral Inner Mongolia, People’s Republic of China. Ore Geology Reviews, 20, 139–169.Pirajno F, Chen Y J, 2005. Hydrothermal ore systems associated with the extensional collapse of collision orogens. Extended Abstract of SGA2005 Conference, Springer, Beijing, in pressRui Z Y, Goldfarb R J, Qiu Y M, Zhou T H, Chen R Y, Pirajno F, Yun G, 2002. PalaeozoicEarly Mesozoic gold deposits of the Xinjiang Autonomous Region, northwestern China. Mineralium Deposita 37, 393418.Sengor, ., Natal’in, ., 1996. Paleotectonics of Asia: fragments of synthesis. In: Yin, A., Harrison, . (Eds.), The Tectonic Evolution of Asia. Cambridge