Podrobnosti záznamu

Název
    Kontaktní viséit a konkrecionální apatit z jeskyně Domica
Údaj o odpovědnosti
    Václav Cílek, Karel Melka, Anna Langrová
Autor
    Cílek, Václav, jr.
    Langrová, Anna
    Melka, Karel
Jazyk
    slovensky
Zdrojový dokument - seriál
    Slovenský kras
Svazek/č.
    Roč. 39
Strany
    s. 25-35
Rok
    2001
Poznámky
    2 obr., 2 fot., 3 tab., 20 bibl.
    Anglické resumé
    il.
    Zkr. název ser.: Slov. Kras
Předmětová skupina
    apatit
    asociace minerální
    guano
    holocén
    jeskyně
    kras
    kvartér Západních Karpat
    ochrana přírody
    viséit
    zeolity
Geografické jméno
    Slovensko
    Slovenský kras
Klíčové slovo
    Apatit
    Domica
    Jeskyně
    Konkrecionální
    Kontaktní
    Viséit
Abstrakt (anglicky)
   The acid solutions derived from guano accumulation and possibly from Neolithic antropogene activities are percolating through cave sediments of Dome of Mysteries of Domica system. The brushite and gypsum are formed directly under guano piles (Kašpar, 1940) but further down to the slope the other phosphates precipitate. The soft, chalky, yellowish apatite forms small concretions some 2-16 mm in diameter embedded in terra rosa clayey sediment. The apatite bearing horizon is localised above ultra-fine, almost impenetrable layer of brown massive clay. The apatite concretions resemble limestone clasts and flowstone pieces. They may have the calcite nucleus. It is concluded they originate by cold metasomatosis of calcite. The other reactions are taking place at the contact of clayey infillings and limestone. The white, soft phosphate crusts up to 3 cm thick devoid of carbonate are formed by microcrystalline mixture of several phosphates.
   Two minerals prevail (determination on basis of several X-ray grafs, difractograf Philips, and chemical composition - EDAX): apatite and viséite. Two other phosphate phases (amorphous to poorly crystalline) were found as well. The Ca-Al phosphate forms minute grains mixed with viseite. The needle like phosphate has the apatite composition but it contains 3 - 5 per cent of Al and the same amount of Si. The composition of phosphates is variable within few microns (Table 1, 2, 3). We believe that we are confronted with two simultaneous processes:- the reaction between acidic guano solutions, clay matrix and the limestone surface that result in origin of apatite and viseite and unhomogenous mixture of amorphous to poorly crystalline phosphates.- the ageing and weathering of Ca-phosphate (apatite) and its gradual replacement by less soluble aluminous phases.The viseite is new mineral for Slovakia and it represents the third find in karst cavities worldwide.
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    12. 10. 2007
Datum importu
    8. 8. 2012