焦家断裂带三维结构模型及其数值模拟:以新城金矿床控矿构造为例

3D Ore-Controlling Structural Model and Numerical Simulation of Jiaojia Fault Zone: A Case Study of the Xincheng Gold Deposit

胶东是中国探明金资源量最多的地区,其中焦家金矿带已探明金资源量>1000t。金矿床(体)严格受焦家主断裂及其下盘次级断裂/裂隙系统控制,构建断裂构造控矿模式长期以来都是胶东金成矿系统理论与勘查系统实践亟待突破的关键问题。本文通过典型剖面构造-蚀变-矿化岩相填图、露头尺度构造解析、三维结构模型及有限元数值模拟,剖析典型金矿床(体)分布与不同级别、序次和型式的控矿构造的关系,初步总结焦家金矿带控矿规律,构建断裂带三维结构模型及其控矿模式,并应用有限元数值模拟取得了良好的效果。

Jiaodong peninsula is a key gold resource district in China and one of the most important gold producer area in the world,within which the Jiaojia gold belt has proven gold resources of more than 1000 tons.The ore bodies in the belt are strictly controlled by the second-order faults(fractures)in the footwall of the Jiaojia Fault Zone,therefore,ore-controlling structural model is critical for the study of gold mineralization and ore exploration in the region.Thus,we focused on typical cross sections of these gold deposits,mapped the structural-alteration-mineralization networks,analyzed the architecture of the Jiaojia Fault Zone by outcrop scale,established 3D geological model for finite element simulations.In order to reveal the rule of ore controlling structures and the mechanism of structural control on the massive gold activation and enrichment,we systematically analyzed the relationship between the distribution of gold deposits(orebodies)and the ore-controlling structures of regional,outcrop to mineral scale.The ore-controlling structural model and the numerical simulation could provide theoretical basis for the greenfield prospecting in the Jiaojia Fault zone.