Weathering In the zone of weathering, some materials
are broken down and others are formed.
Changes in pore water chemistry influence the interparticle
forces and flocculation–deflocculation tendencies.
Weathering can disrupt the initial soil fabric.
Cyclical wetting and drying and freezing and thawing
disrupt weak particle assemblages and intergroup
associations. Wetting generally means weakening and
may lead to collapse of some structures, particularly
those with open fabrics where particles are only
weakly bonded, such as in loess. Shrinkage associated
with drying collapses open particle arrangements and
creates domain-type aggregates in some soils and tension
cracking in others. Drying concentrates clay
around sand and silt particles and between their contact
points. Ice lens formation in frost-susceptible soils can
open cracks and fissures, followed later by collapse on
thawing.