四川拉拉铜矿构造成矿动力学机制

通过对矿区区域构造背景、矿区构造特征、构造控矿特征的研究,得出了矿区岩石圈在经历了火山地堑、挠曲沉降和回返褶皱封闭几个构造-岩浆演化阶段后,形成了该区东西向和南北向构造叠加格局。早期东西向张性断裂构造为含矿岩浆的侵位提供了通道和空间,控制了含矿岩体的分布范围和展布形态,促使了成矿元素的初始富集,中期东西向叠瓦式冲断-褶皱构造体系应是成矿期构造,它为成矿元素的活化、迁移、富集、成矿提供了动力、通道和空间,晚期南北向褶皱构造应是成矿后构造,它对矿床起着改造作用。

TECTONO-METALLOGENIC MECHANISM FOR THE LALA COPPER DEPOSIT, SICHUAN

The Lala copper deposit is tectonically located in the middle rift-valley of the Chuandian passive margin.The western Huili-Dongchuan aulacogen.crust in the studied area had undergone several phases of tectonic-magmatic evolution:volcanic graben,flexure and folding inversion,hence the basement was superimposed by EW and SN-trending structures which constrained the association of deposits.The tectonic impact on the mineralization can be divided into three stages based on the analyses of regional structures and tectonic characteristics in the ore district.In the early stage,the stretching faults offered intruding pathways and spaces for the ore-bearing magmas,which controlled the spatial distribution and occurrence of the mineral deposits,and actuated metallogenic elements to be enriched initially.In the middle stage,the EW-trending superimposed thrust structures and fold system may represent the mineralization epoch which could have offered a kinetic energy,pathway and space to promote migrating,concentrating and mineralizing of the ore-forming elements.In the later stage,the SN-trending folds may represent the post-metallogenic epoch structures which could have a transforming effect on the deposit.