江西省冷水坑银铅锌矿床铁锰碳酸盐角砾岩成因研究  

A genetic study of Fe-Mn carbonate breccias in the Lengshuikeng Ag-Pb-Zn deposit,Jiangxi Province

作　　者：孙建东[1,2] 骆学全[1] 张雪辉[1] 张春茂[2] 李春海[1] 余明刚[1] 朱意萍[1] 宗雯[2] 

机构地区：[1]南京地质矿产研究所,江苏南京210016 [2]成都理工大学,四川成都610059

出　　处：《中国地质》2014年第2期484-496,共13页Geology in China

基　　金：中国地质调查局项目(1212011120846)资助

摘　　要：江西省冷水坑银铅锌矿床的铁锰碳酸盐角砾岩层与顶底板侏罗系火山杂岩呈整合接触关系,填隙物内存在清晰可辨的火山凝灰物质。铁锰碳酸盐角砾岩的稀土元素配分型式属于轻稀土富集的右倾型,稀土组成特征有类似于正常湖相碳酸盐岩低的稀土总量,又类似于正长质岩浆岩的正Eu异常特征。碳氧同位素显示其形成环境属于陆相火山湖泊,陆相沉积岩与岩浆岩均为成岩提供了物质来源。通过顶底板火山杂岩锆石U-Pb年龄的限定,指示在155Ma左右,铁锰碳酸盐角砾岩经历了陆相火山湖泊沉积-火山喷发使之角砾化-正长质岩浆物质混入的成岩过程。The Fe-Mn carbonate breccias strata are in conformable contact with the roof and floor Jurassic volcanic complex in the Lengshuikeng Ag-Pb-Zn deposit of Jiangxi Province,with clear volcanic tuffaceous substance existent in interstitial materials.The REE distribution patterns are right-oblique,and the composition characteristics are similar to features of lower total rare earth content of normal lacustrine carbonate and positive Eu abnormal characteristics of pyroxenitic magmatic rocks.C,O isotopes show that the deformation occured in continental volcanic lakes,and continental sedimentary and magmatic rocks provided diagenetic material source.The zircon U-Pb age of the roof and floor volcanic complex is constrained around 155 Ma,and the Fe-Mn carbonate breccias underwent a diagenetic process of sedimentary-volcanic eruption of continental volcanic lakes,with the addition of the intrusion of pyroxenitic magmatic rocks.

关 键 词：冷水坑 铁锰碳酸盐 成因 过程 

分 类 号：P618.4[天文地球—矿床学] P618.52[天文地球—地质学] P588.212.5