Palaeoclimatic event at the Lochkovian-Pragian boundary recorded in magnetic susceptibility and gamma-ray spectrometry (Prague Synclinorium, Czech Republic)

The MS and GRS stratigraphic records of three Lochkovian-Pragian boundary sections representing different depositional conditions have been evaluated. All studied sections are characterized by increased MS magnitudes from Lochkovian to Pragian. Another prominent characteristic is a turnover in the Th/U ratio; the Pragian magnitudes are usually 2-4 times higher than the Lochkovian ones. Based on a combined physical stratigraphic and sedimentological approach a previously reported regressive event at this time interval is ascribed to climate warming accompanied by enhanced carbonate productivity while eustatic sea-level changes probably played only a minor role, which was locally also combined with synsedimentary uplift.