Radial migration of siderophilic (Co, Cr) and chalcophilic (Zn) trace elements in the soilsof mountain range Ergaki (West Sayan)

The analysis of interconnection between the distribution of elements ingrounds and their genetic peculiarities is an important task of soil elemental composition studying of different types. For a number ofgrounds these questions are studies quite well, however, the grounds of the Western Sayan, especially the mountain range Ergaki, havenot been studied in this relation. The object of the study is topsoil of the mountain range Ergaki. The aim of the study is to establish theintraprofile distribution law of microelements (Co, Cr, Zn) in the Ergaki topsoil. Macro-morphological studies on the territory of themountain range Ergaki have registered the formation of different types of ground profile. According to the horizon combination, all thestudied grounds can be determined as alluvial grey humus gley soils (AY-G-CG~~); grey soils (AY-AEL-BEL-BT-C); typical rustysoils (AY-BFM-C); typical brown soils (О-AY-BM-C), mountain-meadow soils (Ad-A-ВC-C). The research showed that typical rustyand brown soils, as well as mountain-meadow soils, in terms of humus content can be characterized as of high humus, meanwhile alluvialgrey humus gley soils  as of medium humus. In terms of pH quantity of the aqueous extract all the examined types are characterizedby acid and weak-acid environment reaction - acidity goes down to the soil-forming rock. An insignificant number of carbonateshave been found in all the studied soil types. The grounds of the mountain range Ergaki are characterized by high content of active oxideFe2O3 that can be explained by mineralogical makeup of the soil-forming rock, which is presented with granites and metamorphic slates.Aluminium active oxide quantity is insignificant and increases gradually to the soil-forming rock. Eluvial-illuvial differentiation ofAl2O3 occurs only in the grey soils profiles. Typical rusty and brown soils, mountain-meadow and grey soils are characterized by theweighting of granulometric composition from loose sand (upper organic horizon) to light loam (mineral horizons and the soil-formingrock). Alluvial grey humus gley soils are not differentiated with respect to granulometric composition and are classified as sandy-loam.The profiles of typical rusty (eluvial facies) and brown soils, alluvial grey humus gley soils are faintly differentiated with respect to thecontent of Co, Cr and Zn, characterized by descending migration and accumulated to the soil-forming rock. The analysis of cobalt,chromium and zinc radial differentiation showed that for the under test soils radial heterogeneity is generally ill-defined. The averagezinc storage is registered in the grey and typical rusty soils of trans-eluvial facies catenas of the northern and southern exposure. Cobaltis poorly stored in the mountain-meadow soils profile (trans-eluvial facies). In profiles of the other tested soils forming on the surfacesof eluvial, trans-eluvilal accumulative and superaquatic geochemical facies there is a scattering of Zn, Co и Cr.

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