The contact between the Variscan and Cadomian blocks in the Svratka Dome (Bohemian Massif, Czech Republic)
Bulletin of Geosciences, volume 79, issue 4;
pages: 243 - 250;
Received 10 December 2003;
Accepted in revised form 12 October 2004;
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The present author recently presented an alternative scenario for the tectonic development of the SE margin of the Bohemian Massif based on field studies of the Thaya Dome (Batík 1999). In the present paper, the tectonic evolution of the Svratka Dome is described and F. E. Suess's classic concept (1912) of Moldanubian nappe displacement over the Moravicum unit is discussed. The weaknesses of Suess's concept are shown, which pertain mainly to the character of the detachment planes and the amount of time assumed for all the supposed processes. An alternative tectonic scenario is that the Svratka Dome, consisting of Proterozoic granitoid and its overlying mantle, had already formed during the Cadomian orogeny. After Early Paleozoic erosion, its exposed nucleus was covered by Early Paleozoic basal siliciclastic sediments, which in turn are overlain by Devonian clastic and carbonate deposits and Early Carboniferous shales and greywackes. During the Variscan orogeny, which occurred from the Late Carboniferous to the Permian, a freshly consolidated and metamorphosed tectonic block was thrust along a steeply dipping plane over the Brunovistulicum. The Variscan phase continued by flat shears with eastern vergency. The last tectonic deformation events with western vergency affected the Svratka Dome during the Alpine orogeny.