The research is devoted to the study concretions Fe-Mn pedofeatures in profile-differentiated soils of the Beskydy Pre-Carpathian region to establish their genesis, classification status and direction of elementary soil-forming processes. Within the Beskydy Pre-Carpathian region, two types of concretions Fe-Mn pedofeatures have been diagnosed: ortsteins in the sod-podzolic pseudogleyed soils and nodules in the brown earth-podzolic soils. Ortsteins have oval or tubular shape with well-defined external contours, clear internal structure with brown rings of Ferrum accumulation and black rings of Manganese accumulation. Nodules of brown earth-podzolic soils have irregular shape, compacted consistency with indistinct diffuse contours, sharp corners, black, dark gray color, confined to the middle part of the profile, namely the eluvial and illuvial horizons. In laboratory conditions, their percentage has been determined and grouped by fractions. Established that, important factors in the formation of concretions Fe-Mn pedofeatures are heavy loam and clay particle size distribution of soils and rocks, profile differentiation by eluvial-illuvial type. The loamy granulometric composition of soil-forming rocks, differentiation of the profile by eluvial-illuvial type, excessive moisture, activity of specific and nonspecific microflora causes gleying of the profile of sod-podzolic pseudogleyed soils and formation of ortsteins boundaries within them. Clay granulometric composition of soil-forming rocks and differentiation of silt profile causes low water permeability and long-term wetting of brown earth-podzolic profile, dominance of regenerative conditions, minimization of gley-eluvial processes and nodules formation in situ. Such differences in the gross chemical composition of ortsteins and fine soil confirm the hypothesis of their formation due to ex situ and the accumulation coefficient indicates the accumulation of Ferrum, which determines the brown color of the ortsteins, and the black rings - due to the accumulation of Manganese. In fine soils and nodules of brown earth-podzolic soils, the distribution and percentage of elements are almost the same. The accumulation coefficient indicates the accumulation of Manganese, the accumulation of other oxides less than one, which confirms the theory of their formation due to in situ, formation under the action of intrasoil clay and the minimum intensity of the gley-eluvial process. Gross forms of Ferrum, its silicate, non-silicate, crystallized, amorphous forms in the profile-differentiated soils of the Beskydy Pre-Carpathian region and Fe-Mn pedofeatures formed within genetic horizons were determined and evaluated, with the aim of diagnosing elementary soil-forming processes and establishing genesis. The study of the elemental and mineralogical composition of Fe-Mn pedofeatures has been performed by micro-X-ray spectrometry. It is established that the internal structure of the ortstein is composed of a system of concentric rings, which differ in color, and within them different chemical elements are accumulated. The content of Ferrum determines their brown color, and the formation of black rings due to the predominance within them of Manganese, Aluminum and Calcium. Nodules are characterized by an irregular shape, the elemental composition of the internal structure is homogeneous, but their surface is covered with films within which a significant percentage is Oxygen, Manganese, Aluminum, Silicon and Iron, their dark gray, black color causes Magnesite. The results of our study demonstrate that in profile-differentiated soils two types of concretions Fe-Mn pedofeatures should be distinguished: ortsteins and nodules, which differ in morphological and micromorphological features, gross chemical composition and ratio of forms of iron.
