德合龙洼；硫同位素；铅同位素；铜（金）矿；流体包裹体

Sources of ore-forming materials of Dehelongwa copper（gold） deposit in Qinghai Province, China

摘要：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，包含石英一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：矿区矿石硫样品矿。（ScDT）值分布范围较宽（-3．08×10^-3-7．00×101），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Tll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一△y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。

Abstract： The Dehelongwa copper（gold） deposit, located in the north-east part of Qinghai-Tibet Plateau, is a magmatic hydrothermal deposit and the mineralization mainly belongs to magmatic hydrothermal mineralization period including two mineralization stages of quartz-chalcopyrite and arsenopyrite. Based on the research related to the deposit＇s ore-forming geological conditions, the compositions of S, Pb isotopes as well as the characteristics about fluid inclusions and rare earth elements were systematically studied, and the origin of ore-forming materials was discussed. It is shown that the δ34（ScDT） values of ore minerals distribute widely （-3.08×10-3-7.00 ×10-3） and are similar to that of magmatic sulfur, which suggests that the deposit＇s sulfur may be sourced from the intermediate-acid intrusive rocks. Meanwhile, the Pb isotopic composition of ore sulfides is stable and the ore lead is ordinary common lead with little U and Th radiogenic lead. According to the tracer analysis regarding the characteristic parameters, lead composition model and △βγ-△γ, diagram, the conclusion is drawn that the ore lead is typically crust-mantle mixed subduction lead and comes from intrusive magmatical rocks formed under the circumstance of subduction orogeny. Additionally, the geochemical characteristics about fluid inclusions and rare earth elements both suggest that mass ore-forming materials may originatefrom intrusive magmatical rocks while few may be sourced from around strata. Comprehensively, it is believed that ore-forming materials may mainly come from the deep magma formed by subduction orogeny, crust and mantle components both play an important role in providing them.