Macromorphological aspects of the carbonates in soils
CaCO3 accumulations are easily visibles in the soil profiles because of their intense white color
To distinguish them from gypsum and soluble salts it is neccesary to add HCl and to see the effervescence produced by the CO2 formation (
The accumulation of the secondary carbonates usually takes place in depth. As a result the soil seems free of a carbonates in the A and B horizons, whereas the B and C horizons show accumulations.
The depth at which the calcic horizons are found is in direct relationship with the amount of precipitation of the area
CO3 accumulation features
The morphology of the CaCO3 accumulations is a clear expression
of its mobility. They are localised in specific parts of the profile, frequently
included in a totally decarbonatated soil matrix.
Cracks and voids
Nodules. Frequently, powderly soft nodules with diffuse edge.
Coatings on peds.
Coatings on gravels. Sometimes in the inferior part of the gravel.