Acta Geodynamica et Geomaterialia

Title: ASPECTS OF PEDOGENESIS ON ROCK OF THE CENTRAL PART OF THE BOHEMIAN CRETACEOUS BASIN
Authors: Žigová Anna, Šťastný Martin and Adamovič Jiří
DOI: 10.13168/AGG.2019.0031
Journal: Acta Geodynamica et Geomaterialia, Vol. 16, No. 4 (196), Prague 2019
Full Text: PDF file (8.2 MB)
Keywords: Cretaceous sedimentary rocks, clay minerals, Leptosols, humification, Bwk horizon
Abstract: Pedogenesis was studied on clayey sandstones, calcareous sandstones, sandy marlstones and silty marlstones in the Bohemian Cretaceous Basin. These rocks were evaluated by petrography and X-ray diffractometry. The soils were characterized on the basis of a variety of analyses of organic and anorganic components. Soil formation proceeded predominantly under neutral and basic conditions. Calcaric Leptosols are of smaller thickness and less prominent pedogenesis than Cambic Leptosols. The main pedogenetic process in all soils is humification. A rapid reduction of the amount of organic matter in soil profiles is typical for soils on clayey sandstone and sandy marlstone. The content of organic matter decreases gradually down the soil profiles on calcareous sandstone and silty marlstone. The intensity of modern pedogenesis is higher in Cambic Leptosols developed on calcareous sandstone and silty marlstone compared to Calcaric Leptosols on sandy marlstone and clayey sandstone. This is due to the more balanced quartz/calcite ratio in the parent material (1.06 for calcareous sandstone, 1.51 for silty marlstone). It appears that the most important factor in Leptosol development is the parent material and that the development towards Cambisols can be hardly expected on silicate–carbonate rocks with a high proportion of quartz.