Record details

    Plynokapalné uzavřeniny v krystalech kalcitu z Velkolomu Čertovy schody-východ: výsledky analýz a interpretace
Statement of responsibility
    Jurij Viktorovič Dubljanskij, Pavel Bosák
Other titles
    Fluid inclusions in calcite crystals from the Velkolom Čertovy schody Quarry-East (Bohemian Karst): results of analyses and interpretation
    Bosák, Pavel, 1951-
    Dubljanskij, Jurij Viktorovič
Source title - serial
    Český kras
    Roč. 25
    s. 67-74
    2 obr., 1 tab., 4 s.bibl.
    Anglické resumé
    Zkr. název ser.: Čes. Kras
Subject group
    hydrotermální podmínky
    inkluze plynokapalné
    ložisko vápence
Geographical name
    Český kras
    Koněprusy (Beroun)
Abstract (in english)
   Hydrothermal karstfication was connected with the deep circulation of groundwater during increased heat flow associated probably with the main phase of neovolcanic activity in the Bohemian Massif (35-17 Ma). This idea is supported by the finds of Oligocene/Early Miocene pollen grains and decomposed volcanic ash in aerosol speleothems in the Koněprusy Caves. Aerosol speleothems were formed after cave spaces were connected with external atmosphere, i.e. after the major phases of speleogeneis. It is supposed that caves in the Koněprusy Devonian were formed within confined aquifer under phreatic and bathyphreatic conditions. Confinement was caused by less permeable overlying limestone formations and siliciclastic platform cover. Thermal conditions appears when paleogeothermic gradient was increased due to intensive neovolcanic activity.
   Thermal waters invaded cold water caves and changed partly their morphology, leaving two-dimensional mazes with rests of original phreatic tubes along the boundary of permeable and less permeable formations, and phreatic morphologies in the depth. The maximum temperatures were stated to 60-80 °C from large calcite crystals precipitated under phreatic and deeply phreatic conditions. The piezometric level was situated above limestones in Upper Cretaceous platform siliciclastics as indicated by numerous subvertical phreatic tubes ("depressions") filled with sunkened Cretaceous and tertiary sediments after the water buoyancy support decreased. Popcorn-like silivified Koněprusy Rosettes making irregular horizon in two-dimensional maze caves can be result of the drop of thermal water level and mixing with infiltrating meteoric waters. Outer zones of large clacite crystals with precipitation temperatures of about 40 °C can indicate the gradual cooling of the whole system
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    14. 2. 2008
Import date
    8. 8. 2012