Transgressive pulse in the Upper Frasnian of the Janczyce I section (Holy Cross Mts): sedimentology and conodont biofacies

Abstract

The Upper Frasnian part of the Janczyce I borehole section displays sedimentological as well as biofacies evidence of a transgressive event. It corresponds to the lithological boundary between the nodular limestones unit and the laminated marly limestones unit. According to the conodont zonation it represents most probably the late part of the Late rhenana Zone. The transgressive pulse caused deepening of a sedimentary environment probably by ca. 50 m: from near the aerobic/dysaerobic zone boundary under photic and intermittent wave-influence, to anaerobic and aphotic zone below storm wavebase.