Geochemical and volcanological documentation of temporary exposures of Ordovician volcanites during construction of the subway at Praha-Vokovice

 

Zuzana Tesáryová, Vladislav Rapprich, Vojtěch Janoušek

Geoscience Research Reports 46, 2013 (GRR for 2012), pages 235–239
Map sheets: Praha (12-24)

Full text (PDF, 1.18 MB)

 

Abstract

Ordovician volcanic rocks exposed at the temporary exposures excavated during the construction of the subway line A at Praha-Červený Vrch comprise subaerial lava flow, deposits of scoria comprising fallout and possibly also pyroclastic flow deposits. They are all enriched in incompatible elements, resembling within-plate alkali basalts to within-plate tholeiites. Spiderplots normalized by NMORB point to their affinity to an OIB magmatic reservoir, yet with a significant role for crustal contamination. The geotectonic setting most probably corresponded to an attenuated crust, such as shallow-marine rift basin with Cadomian continental basement.