Date Posted:22:41:23 10/15/01 Mon Author: Dr. Chatterjea Subject: Re: Query about Exfoliation In reply to:
(Matthew) Lim Juin Meng
's message, "Query about Exfoliation" on 10:06:40 09/26/01 Wed
Exfoliation is what happens a number of chemical as well as physical weathering take place - it refers to the way the top surface of the rock disintegrates - peels off. It is a combined effect of physical weathering - some expansion - could be due to hydration, some hydrolysis as well as oxidation. All these processes may break the bonds between the chemicals within a rock and the grains may loose their cohesion. As the rock becomes more permeable due to loss of cohesion, more water goes in to cause further decay. This might lead to the upper part of the rock to be disengaged from the lower section, causing a concentric peeling off, known as exfoliation.
