A Natural Example of the Kinetic Controls of Compositional and Textural Equilibration
A Natural Example of the Kinetic Controls of Compositional and Textural Equilibration
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成分和结构平衡动力学控制的自然例子
DOI：
10.1007/978-1-4612-5066-1_5
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
E. Mclellan
中科院分区：
文献类型：
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作者：
R. Tracy;E. Mclellan
在区域变质作用（Griffin，1971; Tracy，1982）和接触变质作用（霍利斯特，1969;卢米斯，1976）中都有结构和成分不平衡的记载。然而，相对较少的作者（例如，卢米斯，1976年;福斯特，1982年）。控制变质反应速率的变量包括热的供给（或去除）速率、物质的供给速率（扩散控制）以及重结晶过程中反应物溶解和/或产物吸收的速率（界面控制）。在接触变质作用的初始高温阶段（即，直到冷却开始），反应速率更可能是界面控制而不是扩散控制，因为热能输入和扩散系数在初始较高的温度下都很大，因此可能不是速率限制。然而，随着温度的下降，热通量和扩散率可能变得越来越重要。速率限制因素将控制组成和结构平衡的性质和程度。因此，扩散控制将导致严格的局部平衡（Fisher，1978），而界面控制可能导致在更大尺度上局部接近平衡（卢米斯，1976）。
Textural and compositional disequilibrium have been documented in both regional metamorphism (Griffin, 1971; Tracy, 1982) and contact metamorphism (Hollister, 1969; Loomis, 1976). However, the significance of kinetics in controlling assemblages, compositions, and textures has been treated by relatively few authors (e.g., Loomis, 1976; Foster, 1982). Among the variables that control the rates of metamorphic reactions are the rate of supply (or removal) of heat, the rate of supply of matter (diffusion control), and the rate of reactant dissolution and/or product absorption during recrystallization (interface control). In the initial high-temperature stages of contact metamorphism (i.e., until cooling begins), reaction rates are more likely to be interface than diffusion controlled because both thermal energy input and diffusion coefficients will be large at the initially higher temperatures and therefore may not be rate limiting. As temperatures fall, however, heat flux and diffusion rates may become increasingly important. The rate-limiting factor will control the nature and extent of compositional and textural equilibrium. Thus, diffusion control will lead to strict local equilibrium (Fisher, 1978) whereas interface control may lead to a partial approach to equilibrium on a larger scale (Loomis, 1976).