四川里伍铜矿含矿岩系地球化学特征及成因分析

Geochemical Characteristics of the Ore-Bearing Rock Series and Genesis of the Liwu Copper Deposit,Sichuan Province

里伍铜矿位于扬子地台西缘江浪变质核杂岩中,近年来受到普遍关注。本文通过地球化学并结合岩石学研究,对其含矿岩系原岩进行恢复并分析大地构造-沉积环境,进而揭示含矿岩系与成矿作用之间的关系,探讨矿床成因。研究表明以里伍铜矿为代表的"里伍式"铜矿含矿岩系为一套被动大陆边缘含火山质的砂泥质海相沉积岩,主要由石英岩、云母石英片岩和云母片岩组成,夹少量变基性岩。成矿物质主要来源于含矿岩系本身,成矿作用具有多期次、多成因的特点,主成矿作用为燕山期中高温热液交代充填成矿,矿床受韧性剪切带和穹窿构造控制明显。成因上属于海相沉积-改造型矿床。

The Liwu copper deposit has drawn wide attention in recent years.It is located in the Jianglang metamorphic core complex,western margin of the Yangtze platform.Through research of the ore-bearing rock series by petrology and geochemistry,their protoliths were reconstructed and the tectonic-sedimentary environment was analyzed.Furthermore,ore genesis and the relationship between ore-bearing rock series and mineralization were discussed.The results show that the protolith of the Liwu rock group is a set of argillaceous-arenaceous marine sedimentary rocks in the passive continental margin,containing a little volcanic rocks.Metallogenic materials mainly come from the ore-bearing rocks proper,and the mineralization is characterized by multiple phases and many genesis.It was formed during the Yanshan period （133-143Ma） by middle to high hydrothermal fluid mineralization,.Furthermore,it is controlled by ductile shear zones and dome structure.The genesis is of a reformed marine sedimentary type.