The Ordovician rocks of Pobroszyn in the Łysogóry region of the Holy Cross Mountains, Poland

Abstract

In the village of Pobroszyn near Opatów, a faulted section of Ordovician deposits represented by upper Tremadoc clayey-silty lithofacies, upper Arenig carbonate-phosphorite lithofacies and Upper Ordovician claystones with limestone interbeds, were identified. The upper Tremadoc is dated on basis of acritarch. This is the first time that upper Tremadoc deposits have been documented in the Łysogóry region. The late Arenig transgressive deposits were probably preceded by emergence in the latest Tremadoc and early Arenig. The Ordovician rocks from Pobroszyn are intensely tectonised. Two groups of faults, oblique and longitudinal, are distinguished. The first one strikes from 120–140°, and dip to NE at 40–45°, and the second one that strikes 15–25° and dips 65–80° to E.