Record details

Title
    Variscan orogeny in the Eastern Alps and Bohemian Massif: How do these units correlate?
Statement of responsibility
    Franz Neubauer, Robert Handler
Other titles
    Aspects of Geology in Austria (Variant.)
Author
    Handler, Robert
    Neubauer, Franz
Language
    anglicky
Source title - serial
    Mitteilungen der Österreichischen geologischen Gesellschaft
Vol./nr.
    Vol. 92
Pages
    p. 35-59
Year
    1999
Notes
    10 obr., 2 tab.
    il.
    Obsahuje bibliografické odkazy
    Zkr. název ser.: Mitt. Österr. geol. Gesell.
Subject group
    Český masiv
    geochronologie
    Gondwana
    kolize desek
    metamorfika
    metamorfóza
    paleozoikum
    příkrov
    terán
    vrásnění variské
    zóna suturová
Geographical name
    Alpy východní (Rakousko)
    Česká republika
    Rakousko
Keyword
    Alps
    Bohemian
    Correlate
    Do
    Eastern
    Massif
    Orogeny
    These
    Units
    Variscan
Abstract (in english)
   Basement units of the Eastern Alps and their lateral extension within the Carpathian arc and Dinarides (Alpine-Carpathian-Dinaride belt: ACD) include the principal suture zone of the southern branch of the European Variscides with generally ca. southward-, Gondwana-directed shortening. This contrasts with the Bohemian Massif (BM) where shortening was directed towards NNE, forming a syntaxis and orocline of the Variscan orogen due to indentation of the paleo-Alpine indenter into the combined Cadomian/Saxothuringian/Brunovistulian blocks. Both the ACD and BM basement units comprise continental fragments with a distinct pre-Carboniferous history. In the Bohemian Massif, the Moravo-Silesian block was overridden by the Gföhl terrane after consumption of the Raabs oceanic tract. The principal stage of deformation at highest P-T conditions was short (ca.
   345-340 Ma) and also led to exhumation of hot mantle slabs along the suture, which contributed heat to partially remelt the continental orogenic wedge. In the ACD belt, "externally" located, mainly medium-grade metamorphic units ("Variscan peri-Mediterranean metamorphic belt") overrode the internally located, peri-Apulian, fossil-bearing Noric-Bosnian terrane. Along the suture, remnants of Silurian-Devonian orogenic crust is preserved, which formed during a long-lasting Early Paleozoic period of subduction. The Variscan boundaries between these units of the ACD belt were entirely reactivated during Alpine tectonic processes. Consequently, the Carboniferous geodynamic evolution of the ACD belt comprises the following tectonic processes, due to continent-continent plate collision: (1) The consumption of pre-Carboniferous oceanic basins is inferred by the presence of ophiolitic sequences that subducted to depths corresponding to 27 kb (ultra-high pressure metamorphic conditions) ca.
   at the Devonian boundary. (2) Tonalite-dominated suites intruded contemporaneously and formed above a subduction zone (e.g. the Helvetic "Cetic massif")
Contributor
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
    U
Entered date
    9. 2. 2007
Import date
    8. 8. 2012