Gorstian palaeoposition and geotectonic setting of Suchomasty Volcanic Centre (Silurian, Prague Basin, Teplá-Barrandian Unit, Bohemian Massif)
Abstract
A multidisciplinary palaeomagnetic, whole-rock geochemical and volcanological study was carried out in Gorstian deposits of the Suchomasty Volcanic Centre in the western segment of the Prague Basin (Teplá-Barrandian Unit, Bohemian Massif). Phreato-Strombolian eruptions of alkali basalts, transitional between enriched mid-ocean rift basalt and ocean-island basalt, associated with effusions of lava flows within the lower-middle Scanicus chimaera graptolite Biozone at the Vinařice locality, yield a mean palaeomagnetic direction that allows for computation of a palaeolatitude of 24.4 degrees S.
Present data support that the Prague Basin was a continental rift basin, situated on presumed Perunica microplate. The Perunica microplate drifted at southern subtropical palaeolatitudes of 24.4 degrees in Gorstian time and experienced either 170 degrees counter-clockwise or 190 degrees clockwise rotation during the Variscan Orogeny.