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°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° in Gorstian time and experienced either 170° counter-clockwise or 190° clockwise rotation during the Variscan Orogeny.

Keywords::

• Gorstian
• Silurian
• Suchomasty Volcanic Centre
• Prague Basin
• palaeolatitude
• basalt geochemistry

Acknowledgements

The authors appreciate financial support by GAČR project 210-10-2351, supplemented by the Strategic Research Plan of the CGS and by the IGCP 591. Analyses, processing and interpretation of palaeomagnetic data were carried out within the Research Plan of the Institute of Geology AS CR No. AV0Z30130516. Thanks are due to Michael S. Petronis for valuable comments on the manuscript and improving the English, and Jan Kolda for field assistance. Reviews by Oldrˇich Fatka and Ulf Linnemann improved the manuscript.