The term pedofeatures is defined in the Handbook for Soil Thin Section Description as discrete fabric units present in soils and recognisable from adjacent material by a difference in concentration in one or more of their components (for example, a grain size fraction, organic matter, crystals, chemical components) or by a difference in the internal fabric. Birefringent fabrics are not included in the concept of pedofeatures.
Actually, in the majority of the cases, they are reorganisations of the soil materials that cannot be attributed to an inheritance of the original material.
Soil material = Groundmass + Pedofeatures
Below are a few examples in order to clarify
the concept of pedofeatures.
|They are pedofeatures||They are not pedofeatures|
|Clay coatings||Rock fragments|
|Organic matter coatings||Root fragments|
|Iron nodules||Mineral grains|
Description of pedofeatures
The following characteristics of pedofeatures are described:
Contrast with the adjacent material and type of limit
Distribution and orientation
The following types can be distinguished, depending
on their morphology, crystallinity and referred orientation patterns:
Pedofeatures related to voids, grains and aggregates
Pedofeatures unrelated to voids, grains and aggregates
Crystals and crystals intergrowths
Fragmented and deformed pedofeatures
Keys to the morphological classification of pedofeatures
Classification by nature
Six main groups can be distinguished depending
on the material's nature:
Amorphous and cryptocrystallines
Keys to the classification of pedofeatures by nature
Pedofeatures are described by their nature and morphology, for example: textural clay coatings, carbonate crystalline nodules, etc.