Podrobnosti záznamu

Název
    The Moldavite Strewn Field
Údaj o odpovědnosti
    Vladimír Bouška
Další názvy
    Das Moldavit-Streufeld
Autor
    Bouška, Vladimír
Jazyk
    anglicky
Zdrojový dokument - seriál
    Chemie der Erde
Svazek/č.
    Vol. 58, no. 3
Strany
    p. 321-343
Rok
    1998
Poznámky
    3 obr., 7 fot., 5 tab., 2 s.bibl.
    Německé resumé
    Zkr. název ser.: Chem. d. Erde
Předmětová skupina
    chemismus hornin
    kenozoikum
    miocén-střední
    moldavit
    sedimentologie
    tektity
    terciér Českého masivu
Geografické jméno
    Česká republika
    Rakousko-Niederösterreich
    SRN-Sachsen
Klíčové slovo
    Field
    Moldavite
    Strewn
Abstrakt (anglicky)
   The greatest number of moldavites have been found in Southern Bohemia (České Budějovice-Třeboň area), corresponding to about 77.3% of all finds. Moravian moldavites constitute 19.5% of all moldavite finds, while Radomilice area in Southern Bohemia possesses only 3.1% of moldavites of the whole moldavite strewn field and the Lusatian area only 111 pieces found up to day, the Cheb area 38 and Austrian area about 15 moldavites. The fall of moldavites 15 million years ago (at the boundary between the Middle and Upper Badenian) was not homogenous and this inhomogeneity has been preserved in the moldavite strewn field in spite of later redeposition into younger sediments. The main differences in the chemical composition, trace element contents and a number of the other parameters. e.g.
   colour distribution, bubble frequently, lechatelierite content, the presence of other mineral grains in the glass matter, the variance in oxygen isotopes and maximum projectionsphericity values, have remained preserved for several groups of localities and led to the distinguishing of moldavite partial strewn fields or subfields. It can be stated that certain areas with moldavites of similar properties are encountered and the rough zonation of the strewn field observed. These are the moldavites from the Radomilice area (most acidic, low alkalies content), the moldavites from the České Budějovice-Třeboň area as well as the Cheb area and moldavites found in Austria with frequent bubbles and lechatelierite grains and the moldavites from Moravia and Lusatia (low CaO + MgO contents, relatively high total iron and alumina).
   Stratigraphically, the moldavite-bearing sediments belong to the Lower Sarmatian (greenishgrey sandy clayes with montmorillonite, loc.: Vrábče-Nová Hospoda, Jankov, Besednice-brickyard), to Lower Romanian (Formation of moldavite-bearing, sandy gravels and/or feldspathic sandy gravels, loc.: Chlum nad Malší, Ločenice, Koroseky, Slavětice, moldavites from Cheb area and Lusatian occurrences), to Pleistocene gravels (Radomilice, localities in the surrounding of Znojmo) and slope loams and scree (Brusná) or Holocene alluvia along present-day rivers. Moldavites from the Horn region in Austria most probably could have been transported from the southern part of the Třeboň Basin by Pliocene or Pleistocene streams or they could belong to a small independent strewn subfield
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    25. 3. 2008
Datum importu
    8. 8. 2012