(1. 中南大学 地球科学与信息物理学院，长沙 410083;
2. 中南大学 有色金属成矿预测教育部重点实验室，长沙 410083;
3. 新疆有色地质勘查局701队，昌吉 831100)
摘 要: Beroen位于厄瓜多尔西南大洋增生地体和原生大陆地体拼接缝合带的东侧。基于矿区围岩和主要硫化物的硫铅同位素特征进行分析。除磁黄铁矿外，其他硫化物平均δ34S为0.1%，来源于深部岩浆来源硫，并有结晶基底还原硫的贡献。围岩及硫化物的206Pb/204Pb为18.605~19.147，207Pb/204Pb为15.621~15.694，208Pb/204Pb为38.378~38.967，放射性成因的异常铅，经历3个阶段，中晚白垩纪前在地幔中为均质的非放射成因铅;始新世时期，富集地幔岩浆源形成，并在浅地壳同化吸收Chaucha和Macuchi基底岩石的放射性铅;在中新世矿床形成时，与浅地壳层岩浆房的热液系统有关的成矿流体淋滤围岩的放射成因铅，在矿石矿物中更加富集地壳铅成分。同时，Chaucha成矿区矿床的矿石矿物铅同位素组成比围岩和中安第斯矿床更富集放射成因铅，这与厄瓜多尔南部中晚第三世大量中小型体积侵入体侵位有密切关系。
关键字: 铅硫同位素;成矿物质来源;淋滤;吸收;Beroen金银矿;厄瓜多尔西南部
（1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China;
2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals, Ministry of Education,
Central South University, Changsha 410083, China;
3. No.701 Geological Party, Xinjiang Geoexploration Bureau for Nonferrous Metals, Changji 831100, China）
Abstract:Ecuadorian Beroen deposit locates east of the suture zone of Chaucha continental terrane with Macuchi oceanic terrane. The Pb and S isotope compositions of main sulfides and wall rocks were studied. Excluding the pyrrhotite, δ34S value average is 0.1%, suggesting that a mantle magmatic sulfur source, with the contribution of a basement biology reductive condition sulfur source. The 206Pb/204Pb is 18.605-19.147, 207Pb/204Pb is 15.621-15.694, 208Pb/204Pb is 38.378-38.967. At first, before later Cretaceous, there is the nonradiogenic lead in mantle; then on Oligocene, enriched mantle-derived magmas ascend to the lower crust, and interact with the basement rock of Macuchi and Chaucha terranes assimilating radiogenic lead; on Miocene, the ore fluids derive from the hydrothermal systems of shallow crustal magma chambers, also react and leach the radiogenic lead from wall rocks. Also the mineral deposits in Chaucha area have significantly higher 207Pb/204Pb values than that of their wall rocks and the central Andean lead province. This can be due to small volumes of parental magma emplaced at shallow crustal levels.
Key words: lead and sulfur isotope; ore-forming material origin; leach; assimilate; Beroen gold-silver deposit; Ecuadorian Southwest
