Record details

Title
    Intrusive Geometries and Cenozoic Stress History of the Northern Part of the Bohemian Massif
Statement of responsibility
    Jiří Adamovič, Miroslav Coubal
Other titles
    Magmatism and Rift Basin Evolution (Variant.)
Author
    Adamovič, Jiří, 1965-
    Coubal, Miroslav
Language
    anglicky
Source title - serial
    Geolines
Vol./nr.
    Vol. 9
Pages
    p. 5-14
Year
    1999
Notes
    6 obr., 2 s.bibl.
Subject group
    dajka
    geochronologie
    geometrie
    intruze
    kenozoické vulkanity Českého masivu
    křída-svrchní
    napětí
    paleotektonika
    terciér
    terciér Českého masivu
    zóna riftová
Geographical name
    ČR-Čechy
Keyword
    Bohemian
    Cenozoic
    Geometries
    History
    Intrusive
    Massif
    Northern
    Stress
Abstract (in english)
   During its Cenozoic history, the Bohemian Massif (BM) located in the foreland of the Alpine Orogen was subjected to a series of regional intraplate stresses of different parameters. This article combined the former results of paleostress analysis with the analysis of geometric of K/Ar-dated intrusive bodies (77-9 Ma, n=78) in order to refine the paleostress time scale for the northern part of the BM. The mechanical model of magma emplacement into an elastic host rock formulated by Pollard (1973) was used as basis for the determination of the direction of maximum principal stress component from the intrusion shape in horizontal cross section. SW compression with reverse faulting and emplacement of dykes of the pre-rift series (Campanian-L.Eocene) SW of the Lužice fault. The U.Eocene-M.Miocene extension-dominated period gave rise to the subsymmetrical structure of the Ohře Rift and subsequent graben formation.
   Uneven aeal distribution of intrusive bodies indicative of rift-related N-S extension evidences progressive eastward spread of the rift. Paleostress phase ß1 of E-W to NE-SW extension was effective in the eastern part of the Ohře Rift adjacent areas of the Bohemian Massif in the interval of 40-26 Ma. Phase ß2 to N-S extension, probably representing an autonomous stress regime of the ohře Rift dominated at 34-24 Ma (central part) or 26-24 Ma (eastern part). Phase ß3 of approx. NW-SE extension with an increasing intensity between 24 and ?16 Ma resulted in the formation of the present fault-confined graben
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    25. 3. 2008
Import date
    8. 8. 2012