In 1965 the PD-1 mapping borehole was drilled in the classical location in Březno u Loun in the Ohře facies region. It was examined by many authors with various results. In 2006 the re vision of these results was pe rformed in archival samples. Carbonate content and insoluble residue minerals were determined. The gathered data were compared with similarly examined boreholes in the Bohemian Cretaceous Basin. The correlation showed that in the western and eastern Poohří region the profiles with different stratigraphy level were compared. After the elimination of this discrepancy the actual stratigraphy of the Poohří region can be easily compared with the other regions of the basin. The Č. Zahálka's statement of the equivalency of the sediment filling of the Ohře facies region and the Jizera formation in the Kokořín region is correct. This fact was validated by the Pd-1 borehole profile, where, due to a tectonic coupling, yet unknown, missing part of the youngest sediments of the Teplice and Březno formations (the real zone Xd) was conserved., Zdeněk Štaffen., and Obsahuje bibliografické odkazy
Biocrusts are biological communities that occupy the soil surface, accumulate organic matter and mineral particles and hence strongly affect the properties of the soils they cover. Moreover, by affecting water repellency, biocrusts may cause a preferential infiltration of rainwater, with a high impact on the formation of local water pathways, especially for sand dunes. The aim of this study is to shed light on the connections between water repellency and pH, carbonate and organic matter content in two dune ecosystems with different biocrust types. For this, we used contact angle measurements, gas volumetric carbonate determination and organic matter characterization via FT-IR and TOFSIMS. In both ecosystems, moss-dominated biocrusts showed higher water repellency and higher amounts of organic matter compared to algal or cyanobacterial biocrusts. Surprisingly, the biocrusts of the two dune systems did not show differences in organic matter composition or organic coatings of the mineral grains. Biocrusts on the more acidic dunes showed a significantly higher level of water repellency as compared to higher carbonate containing dunes. We conclude that the driving factor for the increase in water repellency between cyanobacterial and moss-dominated biocrusts within one study site is the content of organic matter. However, when comparing the different study sites, we found that higher amounts of carbonate reduced biocrust water repellency.