Podrobnosti záznamu

Název
    Cryogenic cave calcite from several Central European caves: age, carbon and oxygen isotopes and a genetic model
Údaj o odpovědnosti
    Karel Žák, Jan Urban, Václav Cílek, Helena Hercman
Autor
    Cílek, Václav, 1955-
    Hercman, Helena
    Urban, Jan
    Žák, Karel, 1957-
Jazyk
    anglicky
Zdrojový dokument - seriál
    Chemical geology (including isotope geoscience)
Svazek/č.
    Vol. 206, no. 1-2
Strany
    p. 119-136
Rok
    2004
Poznámky
    5 obr., 1 pl.
    Bibliografie na s. 135-136
    il.
    Zkr. název ser.: Chem. Geol. (Isotope Geosci.)
Klasifikační znak
    551.3
Skupina konspektu
    55
Předmětová skupina
    datování Th/U
    frakcionace chemická
    izotopy C
    izotopy O
    izotopy stabilní
    jeskyně
    kalcit
    kvartér denudačních oblastí Českého masivu
    morfologie krystalu
    oxid uhličitý
    paleoklimatologie
    periglaciální jevy
    permafrost
    pleistocén-svrchní
    precipitace
    speleotém
Geografické jméno
    ČR-Čechy
    Polsko-střed
    Slovensko
    Srbsko (Beroun, Beroun)
Klíčové slovo
    Age
    Calcite
    Carbon
    Cave
    Caves
    Central
    Cryogenic
    European
    Genetic
    Isotopes
    Model
    Oxygen
    Several
Abstrakt (anglicky)
   Cryogenic cave calcite (CCC), formed by segregation of solutes during water freezing, was found in three Central European caves. This calcite type forms accumulations of loose calcite grains on cave floor. The calcite grains are of highly variable crystal morphology, and of sizes ranging from less than 1 mm to over 1 cm. The most typical feature is their accumulation as loose (uncemented) crystals. U-series dating indicates the formation of CCC in the studied caves during several climatic oscillations of the Weichselian (between 61 and 36 ka BP in the Chelsiowa Jama-Jaskinia Jaworznicka cave system in Poland, between 34 and 26 ka BP in the BUML Cave in the Czech Republic, and between 26 and 21 ka BP in the Stratenská Jaskyňa cave system, Slovakia). At the time of CCC formation, the studied caves were lying in a periglacial zone.
   Detailed C and O stable isotope study of CCC samples revealed that slow water freezing under isotope equilibrium was the dominant formational process in the studied Polish and Czech caves. Significantly higher delta13C values of CCC in the Stratenská Jaskyňa Cave indicate either water freezing in a more opened system with continuous CO2 escape (Rayleigh fractional separation), or participation of another CO2 source. The model of slow water freezing under isotope equilibrium is supported by isolated character of the caves having limited ventilation. In contrast, modern cryogenic cave calcite powders sampled directly on the ice surface of two recently iced caves in Slovakia with high ventilation showed much higher delta18O and delta13C data, similar to cryogenic calcites obtained in experimental rapid water freezing
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    25. 5. 2006
Datum importu
    8. 8. 2012