(1. 中南大學(xué) 有色金屬成礦預(yù)測教育部重點實驗室，長沙 410083；
2. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院，長沙 410083；
3. 青海省第四地質(zhì)礦產(chǎn)勘查院，西寧 810029；
4. 青海省環(huán)境地質(zhì)勘查局，西寧 810007)
摘 要: 青海省肯德可克多金屬礦床位于祁漫塔格成礦帶，礦床產(chǎn)出的大地構(gòu)造背景為柴達(dá)木南緣弧后裂陷構(gòu)造帶中的火山盆地。結(jié)合礦床地質(zhì)成礦條件，通過現(xiàn)場調(diào)查，對礦區(qū)典型的巖漿巖、圍巖及礦石進(jìn)行了化學(xué)全分析、稀土和微量元素分析及鉛同位素分析，總結(jié)了礦床地球化學(xué)特征，查明物質(zhì)來源，探討礦床成巖、成礦機(jī)制。結(jié)果表明：礦區(qū)巖體富鈉，為鈣堿性巖，來源于深部，后期發(fā)生混染，為殼幔混合來源。圍巖稀土元素分析表明：成巖過程有海水參與，礦床具熱水噴流沉積特征。各類礦石鉛同位素的μ值介于9.45~9.75之間，具有深源鉛和殼源鉛特征。鉛同位素特征參數(shù)示蹤、鉛構(gòu)造模式示蹤和Δβ-Δγ 圖解示蹤的結(jié)果表明：鉛來源受巖漿作用影響，主要為殼幔混合鉛。巖漿巖、圍巖及礦體地球化學(xué)特征表明：肯德可克多金屬礦床形成過程受海水影響，具熱水噴流沉積特征，成巖成礦物質(zhì)來源深部，受多源混染影響；礦床演化史漫長，從早期熱水噴流沉積到的晚古生代的構(gòu)造—巖漿活動，深化及擴(kuò)大了成礦體系，晚期熱液活動又對礦床進(jìn)行了疊加改造，具多因復(fù)成特征。
關(guān)鍵字: 地球化學(xué)；成礦作用；鉛同位素；肯德可克；祁漫塔格
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
Central South University, Changsha 410083, China;
2. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
3. Fourth Institute of Qinghai Geological Mineral Prospecting, Xining 810029, China;
4. Environmental Geological Exploration Bureau of Qinghai Province, Xining 810007, China）
Abstract:Kendekeke polymetallic deposit is located in Qimantage ore belt of Qinghai Province and the background of this deposit is a volcanic basin in the back-arc rift tectonic zone of southern margin of Qaidam. Combined with field investigation and ore-forming geological conditions, the geochemical characteristics of deposit were summarized, the origin of the ore-forming materials was ascertained, the rock-forming mechanism and ore-forming mechanism of the deposit were discussed according to the study of lead isotope as well as chemical analysis, including whole-rock analysis，REE analysis and trace elements analysis. Typical magmatic rocks，wall rocks and ores were used as the research objects. The results show that magmatic rocks belong to calc-alkaline series, rich in sodium and derived from the source of crust-mantle mixed deep in the earth. The REE studies of wall rocks indicate the seawater involved in diagenesis and the deposit with characteristics of exhalative sedimentary deposit. The lead isotope research illustrates theμ values of minerals range from 9.45 to 9.75, which are characterized by both deep-sourced and crust-sourced origins. Based on the tracer analysis regarding the characteristic parameters, lead composition model and Δβ—Δγ diagram, the results show that the ore lead mainly is crust-mantle mixed lead and affected by magmatism during the enrichment process. The geochemical properties of magmatic rocks，wall rocks and ore reveal that Kendekeke deposit was affected by seawater in the formation progress and has the properties of exhalative sedimentary deposit. The diagenetic materials and ore-forming material, which were affected by the mixing of multi-source, came from the deep of the earth. The deposit had a long evolution history, begun from the early exhalative sedimentation to Late Paleozoic tectonic-magmatic activities, deepened and expanded the mineralization system, and the late hydrothermal activities superimposed and reformed the deposit, which is a polygenetic compound deposit.
Key words: geochemistry; metallogenesis; lead isotope; Kendekeke; Qimantage
