赣南脉钨矿床控矿断裂的非线性分布特征及其耦合动力学成因机制研究

The southern Jiangxi Province is a famous resource basis in which produced the densest quartz vein-type tungsten deposits in the world. Fracture is the most important ore-controlling factor in this area. The slow progress in the prospecting is probably due to the lack of researches on the dynamic formation mechanism of ore-controlling fractures. The ore-controlling fractures were formed by the coupling of multiple mechano-thermo-hydrological-chemical processes. Such dynamic mechanism is complex and nonlinear. In this program, two typical vein-type tungsten deposits, Piaotang Deposit and Xihuashan Deposit, are studied by multifractal analysis and numerical modeling. The multifratal analysis is employed to delineate the nonlinear spatial distribution of ore-controlling fracture system, and coupled numerical modeling is used to probe the temporal-spatial evolutive laws of the key geological procedure variable and the controls of multiple driving force on the deformation-fracturing process. The complexity of ore-controlling fracture system is quantitatively described and understood by the above researches, which can facilitate the ore-forming theory of vein-type tungsten deposit and provides theoretical basis for the metallogenic prognosis in this area.

赣南是我国乃至世界上石英脉型黑钨矿床最密集产出的地区，断裂构造是区内最重要的控矿因素。对控矿断裂形成的动力学机制的认识不足可能会很大程度上制约脉钨矿床新一轮找矿勘查工作。脉钨矿床控矿断裂的形成是由力学变形-热传递-流体流动-化学反应多场耦合动力学过程控制的，这种机制是复杂、非线性的。本项目选择漂塘钨矿和西华山钨矿两个典型脉钨矿床为主要研究对象，通过多重分形分析刻画控矿断裂系统的非线性空间分布，通过多过程耦合数值模拟探查关键地质过程变量的时空演化规律及各动力因素对岩石变形-破裂的控制作用，从而定量的描述和理解赣南脉钨矿床控矿断裂系统的复杂性，促进脉钨矿床构造-成矿理论的发展，为赣南脉钨矿床的成矿预测工作提供理论依据。

赣南是我国乃至世界上石英脉型黑钨矿床最密集产出的地区，断裂构造是区内最重要的控矿因素之一。本项目通过空间分析、分形计算和数值模拟等方法研究了赣南脉钨成矿系统控矿断裂的非线性特征及其动力学成因机制。区域分形和证据权重分析结果表明钨矿床所在区域都具有高构造分维值，断裂-断裂交点高分维值区域与岩浆岩-地球化学有利证据权区域的交集是成矿潜力最大的部位；漂塘钨矿容矿裂隙和矿脉的形貌分形特征指示了主导成矿的驱动力并非为单一流体压力，而是流体-构造应力-热应力的耦合，其中构造应力可能施加了比流体压力更为显著的影响；本项目建立了漂塘钨矿岩浆岩-构造-矿体的综合地质模型和动力学离散模型，开展了多方案的数值模拟研究，数值模拟的结果表明：较之单一流体压力驱动的模型，构造-流体耦合和构造-流体-热耦合驱动的模型产生了与实际断裂系统更为接近的分形特征值；R/S分析表明构造-流体-热驱动耦合模型模拟过程中的时序行为特征最符合漂塘钨矿多阶段成矿的矿化特征。