复杂形态岩体接触带成矿耦合动力学三维数值模拟:以安庆铜矿为例

安庆铜矿是长江中下游成矿带中重要的矽卡岩矿床,其矿体绝大部分产在形态复杂的岩体接触带上,对于这种矿体定位特点,本文采用数值模拟的方法探讨了其动力学机制和主要的控矿因素。首先以AutoCAD和GO-CAD为平台构建安庆铜矿岩体及围岩的三维实体模型,并通过C++编程实现到模拟软件的模型格式转换,然后以FLAC3D为平台进行安庆铜矿热液成矿过程的力-热-流耦合数值模拟。结果显示,受控于拉张应力场,岩体大部分位置表现为正的体应变;月山岩体东枝南接触带是扩容最为明显的区域,部分岩石单元的大扩容角对扩容区出现有一定的贡献,岩石物理性质的差异及接触带的复杂形态则是其主要原因;岩石扩容部位成为流体汇集的有利场所,汇流部位与明显扩容区及主矿体产出位置相一致,推断矿体的定位是力-热-流共同作用的结果;运算结果亦指示现有矿体深部存在新的有利找矿靶区。

3D-numerical Modeling of Coupled Geodynamic Processes and Mineralization at the Contact Zones of Complex Plutons:Example from the Anqing Deposit,Anhui Province,China

The Anqing Cu deposit is one of the most important skarn-type deposits in the lower-middle Yangtze metallogenic belt. Most of the orebodies are located in the contact zones of intrusions with complex geometries. Using a numerical modeling approach,this paper studies the geodynamic mechanism and principal ore-controlling factors responsible for the formation of the orebodies (in particular their locations). Our modelling workflow involves several steps. Firstly,the three-dimensional entity model and computat...