Record details

Title
    Contrasting P-T conditions during conjugate shear zone development in the Southern Bohemian Massif, Austria
Statement of responsibility
    M. Brandmayr, J. Loizenbauer, E. Wallbrecher
Other titles
    Kontrastierende P-T Bedingungen während der Entstehung konjugierter Scherzonen in der südlichen Böhmischen Masse
Author
    Brandmayr, M.
    Loizenbauer, J.
    Wallbrecher, E.
Language
    anglicky
Source title - serial
    Mitteilungen der Österreichischen geologischen Gesellschaft
Vol./nr.
    Vol. 90
Pages
    p. 11-29
Year
    1997
Notes
    11 obr., 2 fot., 3 tab., 6 s.bibl.
    Německé resumé
    Zkr. název ser.: Mitt. Österr. geol. Gesell.
Subject group
    analýza petrotektonická
    inkluze fluidní
    kataklazit
    moldanubikum
    mylonit
    paleozoikum-svrchní
    podmínky P-T
    posun horizontální
    svrchní paleozoikum brázd
    vrásnění variské
    zóna střižná
Geographical name
    ČR
    Rakousko
Keyword
    Austria
    Bohemian
    Conditions
    Conjugate
    Contrasting
    Development
    During
    Massif
    P-T
    Shear
    Southern
    Zone
Abstract (in english)
   icrofabric analysis and fluid inclusion studies were carried out on a NW-SE striking dextral, and a NE-SW striking sinistral system of conjugate strike shear zones in the southern Bohemian Massif. A large variety of pressure-temperature conditions was found in both fault zone sets. Generally, "higher" temperatures of 650°C were typical for the westernmost shear zones (Pfahl and Danube Shear Zone) whereas "lower" temperature conditions and higher crustal positions were typical for the eastern shear zones (Vitis and Diendorf Shear Zones). The data give rise to a model explaining the geological evolution of the fault systems: Crustal thickening occurs due to large-scale northeastward transpression of an Early Paleozoic terrane onto a Late Proterozoic terrane during the Variscan orogeny. In the very late stages of the orogeny a large mass of plutonic bodies intruded both terranes and led to a high heat flow in all crustal levels.
   This was immediately followed by begin of shear in the west which produced the conjugate shear system. Microthermometric analyses on fluid inclusions reveal contarsting P-T conditions for two of the strike slip shear zones. Furthermore fluid inclusion data indicate an asymetric exhumation in the southern Bohemian Massif caused by Variscan crustal stacking. This led to the exposition of deep-crustal high temperature mylonites in the West and upper-crustal cataclastic rocks in the East. Simultaneously shearing propagated towards the north, opening the Permian pull-apart basins of České Budějovice and Blanice
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    14. 1. 2008
Import date
    8. 8. 2012