摘要
本文提出了一个封闭体系的扩散数学模型,用来描述由于化学扩散而导致球状晶体发生的均匀化作用;结合扩散系数和一些岩石物化知识,就可能模拟待定岩石的温度—时间(T-t)史。作者根据斜长石的相图特征并应用该模型,提出了如何确定斜长石扩散初始条件的方法,描述了湖北省凤凰关地区混合岩浅色体中斜长石的均匀化作用;经计算表明:地壳冷却速率(s)为0.75℃/Ma;所提出的数学模型普遍适用于变质岩的冷却问题。
The paper has put forward a diffusion-mathematical model in the closed system , which describes the homogenization of globular minerals owing to the chemical diffusion, and can be used to model the temperature-time history of some met-amorphic and igneous rocks based on the knowledge of diffusion coefficients and petrological physico-chemistry. We have advanced the method for the, determination of the plagioclase initial diffusion conditions according to the characteristics of the plagioclase phase diagram and this model. The model elaborates the homogenization of plagioclase of the leucosome in migmatites in the Precambrian Dabie Complex of Fenghuangguan area. It's concluded that the crust cooling rate is equal to 0.75℃ /Ma, and the model is generally suitable for the study of the problem of meta-morphic and igneous rock cooling.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
1991年第2期165-172,共8页
Earth Science-Journal of China University of Geosciences
关键词
大别杂岩
地壳
冷却速率
扩散模型
Dabie Complex, diffusion model, homogenization, crust cooling rate.
