Impact of Geomorphology on Carbonate Pedofeatures in the Soils from South of Ahar, Iran

Carbonate accumulation is an important criterion for soil evaluation and classification in arid and semi-arid regions. In this study, characteristics of carbonate pedofeatures at two different landforms of floodplain and pediment were studied using micromorphological techniques. Inherited carbonate features in both landforms are affected by soil forming processes with obvious role of bio-organisms due to either CO2 evolution or drying and wetting of soil fabric. Carbonate microcrystallines in soil profiles of the floodplain indicated that these soils are apparently younger than the soils forming on the pediment. Pediment soils show yellowish carbonate concretions with crystallitic b-fabric which indicate soil forming processes impacts. On the other hand, brownish carbonate concretions, which increase form upper to lower parts, in pediment soils indicate that they are probably inherited from parent material. But these features show an irregular pattern in soil profiles of floodplain.