氧同位素在流体-岩石交换过程中的传输模型  

MODELS OF OXYGEN ISOTOPE TRANSPORT IN THE PROCESS OF FLUID-ROCK INTERACTIONS

作　　者：惠鹤九[1] 陈斌[1] 郑永飞[1] 赵子福[1] 

机构地区：[1]中国科学技术大学地球和空间科学学院,安徽合肥230026

出　　处：《地学前缘》2002年第4期431-439,共9页Earth Science Frontiers

基　　金：国家自然科学基金重点项目 (4 0 0 3 3 0 10 );中国科学院知识创新工程项目 (KZCX2 10 7)

摘　　要：流体控制着地球系统中质量和能量的传输。流体岩石反应过程在岩石圈中是十分普遍的现象。在流体流动体系中 ,流体在岩石裂隙中通过平流、扩散、水动力弥散和动力学弥散等方式进行输运并与岩石发生同位素交换反应。文章首先对封闭体系、“封闭”体系、开放体系以及缓冲体系中的同位素交换模型进行了简单讨论 ,然后在讨论氧同位素动力学交换机制的基础上 ,建立了平衡交换模型和动力学交换模型。结合流体流动的归一化速率、弥散系数和流体岩石的反应速率等变量 ,对流体岩石交换反应的流体运动方程中的Peclet数和Damk¨ohler数进行了讨论 ,并详细解释了它们在流体岩石交换反应过程中的物理意义和地质用途。Fluid controls the transport of mass and energy in the Earth system, and the process of fluid-rock interactions is a very common phenomenon in the lithosphere. Advection, diffusion, hydrodynamic dispersion and kinetic dispersion of fluid in the rock cracks may occur in the system of the fluid flow, and at the same time, the isotopic exchange between fluid and rock phases will occur during these processes. The kinetic mechanism of oxygen isotope exchange is considered, and the models of equilibrium exchange and kinetic exchange are introduced after brief discussion on the isotopic models in the close system, 'closed' system, open system and buffered system. After introducing the time-integrated fluid velocity ( v ), dispersion coefficient ( D ) and exchange rate of isotopes between fluid and rock phases ( u ), parameters of Peclet and Damkhler are introduced to deal with fluid-rock interactions during the fluid infiltration process, and then their physical meaning and geochemical applications are explained.

关 键 词：水-岩反应 氧同位素 动力学交换 同位素前锋 

分 类 号：P597[天文地球—地球化学] P594[天文地球—地质学]