澳大利亚奥林匹克坝矿床铀成矿地质特征  

Geological characteristics of uranium metallogeny in Olympic Dam deposit,Australia

作　　者：徐翅翔 林子瑜[1] 聂逢君[1] 余倩[1] XU Chixiang;LIN Ziyu;NIE Fengjun;YU Qian(East China University of Technology,Nanchang 330000,China)

机构地区：[1]东华理工大学,南昌330000

出　　处：《世界核地质科学》2021年第1期38-46,共9页World Nuclear Geoscience

基　　金：中国核工业地质局项目《铀资源大数据分析与找矿战略研究》(编号:201928-3)资助。

摘　　要：奥林匹克坝多金属铁氧化物角砾杂岩型(IOCG型)矿床是目前世界上已知最大的铀矿和世界前三大铜矿之一,探明铀资源储量2171359 t,品位为0.020%,目前正在开发中。铀矿化产于一个大型、复杂漏斗状热液角砾岩体—奥林匹克坝角砾杂岩(ODBC)中,后者受构造控制,形成于中元古代早期侵入的罗克斯比A型花岗岩中,形成环境类似于玛珥湖高位潜水岩浆火山机构。铀矿化与富含赤铁矿、氧化的热液蚀变组合空间相关,主要铀矿物为沥青铀矿,成矿年龄可能晚于1590~1580 Ma。伸展运动导致的陷落地块有利于保存在近地表形成的富赤铁矿-富铀IOCG型矿床;而周围上升区域将表现出更深的富磁铁矿-贫铀IOCG型矿床类型特点。The Olympic Dam polymetallic iron oxide breccia complex(referred to as IOCG type)deposit is currently the largest known uranium deposit in the world and one of the top three copper deposits in the world.The uranium resource is 2171359 t with a grade of 0.02%,which are under mining.The uranium mineralization occurs in a large,complex funnel-shaped hydrothermal breccia body,which is called“Olympic Dam Breccia Complex(ODBC)”.ODBC is controlled by the structure and formed in the Roxby downs granite,A-type granite,intruded in the early Mesoproterozoic.The formation environment of the breccia complex is a high-level phreatic magmatic volcanic mechanism similar to the Maar lake.Uranium mineralization is spatially related to hydrothermal alteration assemblages rich in hematite and oxidation.The main uranium mineral is uraninite,with a mineralization age maybe later than 1590 to 1580 Ma.The rift block caused by extensional movement is favorable to preserve the hematite rich-uranium rich IOCG type deposit formed near the surface,while the rising area around it shows the characteristics of deeper,magnetite rich and uranium poor IOCG type deposits.

关 键 词：奥林匹克坝矿床 IOCG 成矿地质特征 

分 类 号：P619.14[天文地球—矿床学]