Tuesday, January 08, 2013
Saprock indicates some color change, but no volume/texture/hardness, while saprolite retains original rock volume but is more "rotten" and may flake off easily (reduced strength).
Mottled zone is splotches of red and white showing variable iron movement.
Pallid zone may indicate leaching of iron.
Plasmic zone indicates accumulation of clay particles from the dissolution of feldspar and recrystalization of various clays. Shrink/swell clay particles like may displace grains of quartz, causing accumulations.
Dark reduced zones around plant roots contrast with light oxidized zones along cracks and channels that communicate with above-ground atmosphere.
In the French literature, saprock is the zone where the fabric of the parent rock is conserved, contrasted to the zone above where the fabric has been lost (pedolith).