表生地球化学反应的尺度效应

Scaling Behavior of Surficial Geochemical Reactions

表生环境中的地球化学反应速率具有显著的尺度效应。许多地球化学反应的野外观测速率比实验室观测速率要低2~5个数量级,给不同尺度的研究成果的对比和外推造成了极大困难。本文总结了地球化学反应速率随时间和空间尺度变化的影响因素,着重分析了地球化学反应速率的主控过程随尺度变化的现象,以及亚尺度的非均质性造成的尺度效应。最后介绍了几种尺度转换的研究方法。由于地球化学反应速率的尺度效应普遍存在,在对地球化学反应速率进行外推时需要了解它的局限性以及选取适当的外推方法。

The geochemical reaction rate in the supergene environment has a significant scale effect.The field observation rate of many geochemical reactions is 2 to 5 orders of magnitude lower than the laboratory observation rate,which makes the comparison and extrapolation of research results at different scales extremely difficult.This article summarizes the influencing factors of the geochemical reaction rate changes with temporal and spatial scales,emphasizes the main controlling process of the geochemical reaction rate changes with the scale,as well as the scale effect caused by sub-scale heterogeneity.Finally,several research methods of scale conversion are introduced.Since the scale effect of the geochemical reaction rate is widespread,it is necessary to understand its limitations and select an appropriate extrapolation method when the geochemical reaction rate is extrapolated.