Permafrost-Affected Soils of the Alazeya River Basin: Properties, Mineralogy, and Classification

Physicochemical properties and vertical distribution patterns of clay minerals in the weakly differentiated permafrost-affected soils of the Kolyma Lowland have been studied. These soils are developed under conditions of cold ultracontinental climate within a broad range of landscapes: coastal marsh, alas meadows on the plain composed of the ice complex deposits, and typical northern taiga. Despite the fact that weathering processes are weakly developed at high latitudes, certain features of pedogenic transformation of the initial chlorite–illite association have been identified. These are the presence of (i) vermiculite in the acidic soil horizons of the alas meadow and zonal northern taiga landscapes and (ii) iron hydroxide (lepidocrocite) in the profile of the marsh meadow soil. The soils of zonal taiga woodland are classified as cryozems according to the new Russian profile-genetic soil classification system; their classification position does not cause doubt. Oppositely, the classification of weakly differentiated and differently gleyed soils of intrazonal landscapes (alases and marsh meadows) is open to argument and should be further clarified.