构造-流体-成矿体系的反应-输运-力学耦合模型和动力学模拟  

A COUPLED REACTION-TRANSPORT-MECHANICAL MODEL FOR TECTONIC-FLUID-MINERALIZATION SYSTEM AND DYNAMIC SIMULATION

作　　者：谭凯旋[1] 谢焱石[1] 赵志忠[1] 王岳军[1] 

机构地区：[1]中国科学院长沙大地构造研究所,湖南长沙410013

出　　处：《地学前缘》2001年第4期311-321,共11页Earth Science Frontiers

基　　金：国家自然科学基金资助项目 ( 4970 2 0 2 4);中国科学院"九五"重点项目 (KZ95 2 s1 40 2 ) ;中国科学院知识创新工程重要方向资助项目 (KZCX2 10 1)

摘　　要：建立了一个综合的构造流体成矿体系的反应输运力学耦合动力学模型。利用有限元方法求解岩石变形、断裂作用和断裂网络统计动力学、流体流动、有机和无机地球化学反应及成岩成矿作用、压力溶液和其它压实力学、热迁移的方程组 ,可以对构造流体成矿体系的动力学演化过程进行 1～ 3维数值模拟。模拟的主要内容是在各种过程耦合作用下描述构造流体成矿体系的主要变量的时空演化 :( 1)与成矿流体的形成和性质有关的变量 ,如地层中矿物 (包括成矿物质 )的溶解速率、流体中各组分的浓度与饱和度、流体温度、压力、离子强度等 ;( 2 )与构造变形和流体运移有关的各变量 ,如应力与变形速率、岩石孔隙度、构造 (断裂 )渗透率等 ;( 3 )与沉淀成矿有关的变量 ,如矿物 (金属矿物和脉石矿物 )的成核速率、各矿物的沉淀量等 ;( 4 )上述各有关变量间的时空耦合关系 ,如断裂渗透率时空演化与流体流动、汇聚和成矿的耦合关系等。以湖南沃溪金锑钨矿床为例 ,应用该模型和方法对成矿动力学过程和动力学机制进行了初步的模拟与分析。A comprehensive,coupled reaction\|transport\|mechanical dynamic model for tectonic\|fluid\|mineralization system is described.By using the finite element solution of equations of rock deformation,rock failure and fracture network statistical dynamics,fluid flow, organic and inorganic geochemical reaction and diagenesis,press solution and other compaction mechanisms, and heat transfer, the authors simulate the dynamic evolution processes of tectonic\| fluid\|mineralization system in 1 to 3 dimension. Main content in simulation is the spatio\|temporal evolution of the set of descriptive variables characterizing tectonic\|fluid\|mineralization system state under coupling of various processes as following:(1)variables related to the formation and property of ore\|forming fluid,such as dissolution rate of minerals (including metal minerals) in rock, concentration and saturation of aqueous species in fluid, temperature,pressure,and ionic strength et al; (2)variables related to structural deformation and fluid flow, such as stress, deformation rate,fracture network,porosity and fracture permeability;(3)variables related to precipitation and mineralization, such as nucleation rate of gangue and metal minerals, accumulation precipitation of various minerals et al; (4)spatio\|temporal coupling relation of various variables above, such as the coupling relationship between spatio\|temporal evolution of fracture permeability and flow and focus of fluid and ore\|forming. An example illustrating the application of this model to modeling dynamic evolution processes and mechanism of tectonic\|fluid\|mineralization system is presented for the Woxi Au\|Sb\|W deposit,Western Hunan Province,China.

关 键 词：构造-流体-成矿体系 反应-输运-力学耦合 动力学模拟 金锑钨矿床 湖南 岩石变形 断裂作用 成矿作用 

分 类 号：P618.51[天文地球—矿床学] P618.6[天文地球—地质学]