CAJ | 학술논문

油房沟铜矿为康滇中部地区一处中型铜矿床,是近年发现新的铜矿类型,赋存于中元古代晚期会理群淌塘组中。前人的研究工作较少,本文报道了油房沟铜矿床黄铜矿的 Re-Os 同位素年龄,4件样品的等时线年龄为881±65 Ma (MSWD=1.08),表明其成矿时代为新元古代中晚期,晚于赋矿围岩淌塘组。187Os/188Os初始值为0.588,介于881 Ma时地幔值(0.121)和地壳值(2.586)之间,更接近地幔值。油房沟铜矿属热液脉型铜矿床,其成矿物质可能主要来源于深部地幔,其次为淌塘组富Cu凝灰质碎屑岩。新元古代扬子地台西缘大规模岩浆事件过程中强烈的热液活动是导致两者Cu富集并最终沉淀形成油房沟铜矿最关键的因素。
유방구동광위강전중부지구일처중형동광상,시근년발현신적동광류형,부존우중원고대만기회리군창당조중。전인적연구공작교소,본문보도료유방구동광상황동광적 Re-Os 동위소년령,4건양품적등시선년령위881±65 Ma (MSWD=1.08),표명기성광시대위신원고대중만기,만우부광위암창당조。187Os/188Os초시치위0.588,개우881 Ma시지만치(0.121)화지각치(2.586)지간,경접근지만치。유방구동광속열액맥형동광상,기성광물질가능주요래원우심부지만,기차위창당조부Cu응회질쇄설암。신원고대양자지태서연대규모암장사건과정중강렬적열액활동시도치량자Cu부집병최종침정형성유방구동광최관건적인소。
The recently explored Youfanggou deposit, which is hosted in the Tangtang Formation of the Huili Group, is a medium-sized and new type of copper mineralization in the Kangdian area. Geochemistry study of the mineral deposit is absent, and the Re-Os isotope age of chalcopyrite from the Youfanggou copper deposit is reported in this paper. The isochron age of 4 chalcopyrites is 881±65 Ma (MSWD=1.08), which is later than the sedimentary time of the wall rock. The initial 187Os/188Os ratio of the chalcopyrite is 0.588, which is between the contemporary crustal value (2.586) and the mantle value (0.121), but is closer to the mantle value. We propose that the Youfanggou copper deposit is a hydrothermal copper deposit, and the ore-forming materials come mainly from the mantle and secondarily from the Cu-enriched tuffaceous clastic wall rock. The hydrothermal activity caused by the large-scale magmatism in the Neoproterozoic is the key reason for the leaching and migration of copper from the deep mantle and the wall rock to form the Youfanggou copper deposit.