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德合龙洼铜(金)矿床为青藏高原北东端的一个岩浆热液型矿床,成矿作用主要划分为岩浆热液成矿期,包含石英-黄铜矿和毒砂两个成矿阶段。在分析该矿床成矿地质条件的基础上,系统地研究了矿区矿石硫、铅同位素组成,流体包裹体以及稀土元素特征,探讨了成矿物质来源。研究表明:矿区矿石硫样品δ34(SCDT)值分布范围较宽(-3.08×10-3～7.00×10-3),具有岩浆硫性质,可能来源于矿区侵入的中酸性岩体。各类型矿石铅同位素组成稳定,显示正常铅的特征,U和Th放射性成因铅含量较低。对各类型矿石铅同位素进行特征参数示踪、铅构造模式示踪和-β—-γ图解示踪的结果表明:矿区矿石铅主要为地壳与地幔混合的俯冲铅,主要来源于俯冲造山背景下形成的岩浆侵入体。流体包裹体及稀土元素地球化学特征均表明矿区成矿物质可能主要来源于岩浆侵入体,少许成矿物质可能来源于周围地层。总结矿区矿石硫、铅同位素、流体包裹体以及稀土元素分析结果,表明成矿物质主要来源于深部岩浆,这种岩浆的形成可能与板片俯冲造山有关,地壳与地幔组分均可提供成矿物质来源。
The Dechonglongwa copper (gold) deposit is a magmatic hydrothermal deposit at the north-eastern end of the Qinghai-Tibet Plateau. The mineralization is mainly divided into magmatic hydrothermal mineralization stages including quartz-chalcopyrite and arsenopyrite. Based on the analysis of the metallogenic geological conditions, the authors systematically studied the sulfur and lead isotopic compositions, fluid inclusions and rare earth elements in ore deposits, and discussed the sources of ore-forming materials. The results show that the distribution of δ34 (SCDT) value of ore samples in ore area is wide (-3.08 × 10-3 ~ 7.00 × 10-3), which has the magmatic sulfur character and may originate from the intrusive medium-acid rocks in the mining area. All types of ore lead isotope composition stable, showing the characteristics of normal lead, U and Th radioactive lead content is lower. Lead isotope tracing of various types of ores, trace of lead tectonic tracing and tracing by -β - γ diagram show that ore lead is mainly subducted lead mixed with crust and mantle mainly from the background of subduction orogeny The formation of magma invaded. The fluid inclusions and REE geochemical characteristics all indicate that the metallogenic materials in the mining area probably originated mainly from magma intrusions, and some ore-forming materials may originate from the surrounding strata. Summary of ore sulfur, lead isotopes, fluid inclusions and REE analysis results show that the ore-forming material is mainly derived from deep magma, which may be related to plate subduction orogeny, and the crust and mantle components can provide mineralization Material source.