Record details

Title
    Cherts of the Přídolí Formation and accompanying trace fossils (Pridoli, Silurian), Barrandian area, Czech Republic
Statement of responsibility
    Radek Mikuláš, Pavel Čáp, Radvan J. Horný
Author
    Čáp, Pavel, 1978-
    Horný, Radvan J.
    Mikuláš, Radek
Language
    anglicky
Source title - serial
    Bulletin of geosciences
Vol./nr.
    Vol. 78, no. 4
Pages
    p. 447-457
Year
    2003
Notes
    2 obr., 6 pl., 13 bibl.
    il.
    Zkr. název ser.: Bull. Geosci.
Subject group
    Barrandien
    benthos
    diageneze
    dolomit
    dolomitizace
    gel
    kalcit
    křemen
    nodule
    nový taxon
    pražská pánev
    přídolí
    pyrit
    rohovec křemitý
    silicifikace vápence
    silur
    trace fossils
    vápenec
Geographical name
    ČR-Čechy
    Karlštejn (Beroun)
    Trněný Újezd (Beroun)
Keyword
    Accompanying
    Area
    Barrandian
    Cherts
    Czech
    Formation
    Fossils
    Pridoli
    Přídolí
    Republic
    Silurian
    Trace
Abstract (in english)
   In the area of the 'Amerika' Anticline (central part of the Prague Basin, Barrandian area), bedded cherts are present in the upper part of the Přídolí Formation (uppermost Silurian). According to the study of thin sections, an ideal succession of lithification and diagenesis of these rock was as follows: l. crystallization of cryptocrystalline quartz from gels, which were derived mostly from sponge spicules; 2. nearly contemporaneous appearance of quartz veinlets, 3. fine cracking of the lithified rocks, 4. healing of the cracks by calcite, 5. pressure-induced solution combined with the appearance of stylolite sutures, which consume calcite-filled cracks, 6. crystallization of dolomite along the sutures, 7. partial silicification of the dolomite rhombi, 8. crystallization of pyrite.
   Relative hardness of the bottom and its composition (newly formed silica in the cement) might represent main ecologic stress for in-faunal benthic organisms that caused a development of a dense but monospecific (more correctly, 'monoichnospecific') assemblage. The shaft-like structure, falling to the group of 'plug-shaped' ichnofossils, is designated herein as Pridolichnus pollex igen. et isp. nov.
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    27. 9. 2007
Import date
    8. 8. 2012