Record details

Title
    Cyclicity and duration of Lower Devonian stages: Observations from the Barrandian area, Czech Republic
Statement of responsibility
    Ivo Chlupáč
Author
    Chlupáč, Ivo, 1931-2002
Language
    anglicky
Source title - serial
    Neues Jahrbuch für Geologie und Paläontologie. Abhandlungen
Vol./nr.
    Vol. 215, no. 1
Pages
    p. 97-124
Year
    2000
Notes
    8 obr., 5 fot., 4 s.bibl.
    il.
    Německé resumé
    Zkr. název ser.: Neu. Jb. Geol. Paläont., Abh.
Subject group
    Barrandien
    cyklus sedimentační
    devon-spodní
    Milankovičova teorie
    pražská pánev
    profil geologický
    silur
Geographical name
    ČR-Čechy
    Kosoř (Praha-západ)
    Praha
    Srbsko (Beroun)
    Suchomasty (Beroun)
Keyword
    Area
    Barrandian
    Cyclicity
    Czech
    Devonian
    Duration
    Lower
    Observations
    Republic
    Stages
Abstract (in english)
   Cyclicity of different orders is evaluated particularly in Lower Devonian carbonate sediments. The high-frequency cyclicity, expressed in bedding couplets, shows in selected sections 410-450 couplets in the Lochkovian, 350-380 couplets in the Pragian, around 150 (?) couplets (or bundles) in the Zlíchovian (partly overprinted by discyclic events) and 250-380 couplets in the Dalejan. They point to a comparable duration of the Lochkovian, Pragian and Dalejan, though differences exist, and data on Zlíchovian are not conclusive. The duration of individual bedding couplets is estimated at 17 000-21 000 years (possibly corresponding to Milankovič's earth's axis precessional periods). The megacycles are of two distinct orders: the shorter ones correspond to individual formations, roughly equivalent to Lower devonian stages established in the Barrandian, and comparable with the T-R cycles of some other areas.
   The longer megacycles are expressed by the periodical recurrence of formation couplets with characterical facies groups. The limits of megacycles are marked by events of mostly global character, which show some periodicity but not equal character and effects
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    9. 7. 2007
Import date
    8. 8. 2012