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Soil cover of Přední Kobyla site (Bohemian Karst) genesis: role of clay minerals
Žigová, Anna ; Šťastný, Martin
Soil cover of Přední Kobyla site (Bohemian Karst) is represented by relict soils. Přední Kobyla site is covered by illimerized brown earthifield terra fusca with slight sings of pseudogleization. Fractions 0.01 mm and 0.001 mm from the soil profile are charakterized mainly by kaolinite, illite and quartz. Stage and distribution of plagioclase and feldspar in soil reflect the strong weathering process. In association with clay minerals kaolinite is dominant.
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Pseudokarst caves in the sandstone rocks at Tisá and Rájec (Northern Bohemia)
Mikuláš, Radek
The area Tisá and Rájec is well known as an excellent example of "castellated sandstones". However, its caves, though common and interesting, have never been described in more detail. The caves occur often in upper parts of rock pillars, therefore, most of them are accessoble only by climbers. The most impressive example is the "Cave of the Falcon Tower" , i. e., a systém of narrow horizontal tunnels in two levels, reaching more than 20 m in length.
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Study of stagnant water occurrences and dripping waters in caves: Chemical composition and remarks to corrosion of dripstones
Zeman, Ondřej ; Bruthans, J. ; Filippi, Michal ; Vysoká, H.
Slight stagnant water occurrences (drops) were studied in four caves in the Czech Republic and Slovakia. Major components were analyzed (Na+, K+, Ca2+, Mg2+, SO42-, Cl-, NO3-), pH, conductivity and temperature were measured in the field. Results are shown in table 1. Waters coming from condensation differs by higher amount of sulphate and some other components if compared with dripping waters.
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Environmental tracers (18O, 3H, CFCs, SF6) exploitation for study of mean residence time and flow pattern of dripping water and karst springs (Moravian Karst)
Bruthans, J. ; Zeman, Ondřej ; Jež, M. ; Himmel, J. ; Buzek, F. ; Melková, J. ; Oster, H. ; Geršl, M.
Mean residence time and flow pattern was studied in unsaturated zone of Ochoz Cave in southern part of Moravian Karst by means of 18O in the years 2001 to 2003. The results of study showed relatively long residence time in the unsaturated zone (about 50% komponent with residence time exceeding one year). The proportion components coming from different reservoirs were computed from two components (soil/epikarst; meltwater). The results clearly indicate, that more than 50% of water (nearly 100% in 2003) in dripping waters was derived from soil/epikarst water, which originate from (late) summer precipitations (heavy 18O content)! It means that infiltrating snowmelt water was expelling (by piston flow effect) the summer water from soil and/or epikarst. Water from snowmelt was then lost by evapotranspiration in summer time. If this effect is common in Langer period, it can change composition of d18O in dripping waters and hence also in dripstones precipitating from these waters.
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Ekologické vazby ohledně endolitických producentů mikrovrteb a substrátů v barrandienských vápencích devonského stáří, Česká republika
Hladil, Jindřich
The microboring activity in barrandian seas was generally low. It was limited by relatively cold geostrophic currents in outer parts, and the seafloors in inner basin depressions were also adversely influenced by stagnant d18O-positive and heavy-metal-rich bottom waters. The really flourished microborers were only in two stratigraphical intervals, and both have shown /"redbeds-like/" deposits. The first developed close with major end-Tippecanoe regressions in Praha sequence, and the second occurred in the Daleje-Trebotov sequence. These /"redbeds-like/" periods correspond mineralogically, geochemically and paleobiologically to relatively hot humid climates (~ mesotrophic but well oxygenated waters). It differed from other long intervals characterized by marine Corg and silica burial (cherts)
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