Cambrian Series 2 shallow marine siliciclastics at the margin of the East European Craton: the Ociesęki Formation in Dziewiątle Quarry (Holy Cross Mountains, Poland)

The Cambrian rocks of the Palaeozoic inlier of the Holy Cross Mountains (HCM) in Poland offer a unique window into the sedimentary record on the margin of the Baltica palaeocontinent. The sedimentary features and ichnofossils in the upper part of the Cambrian Ociesęki Formation, which is a siliciclastic shallowing-upward succession exposed in the newly established Dziewiątle Quarry located in the southern HCM, reflect evolution of the depositional environment from offshore to middle, and even upper, shoreface. The age of the succession is constrained by 1) acritarch assemblages suggestive of the Cambrian Series 2 Volkovia–Liepaina Zone in the underlying rocks, and 2) the directly overlying strata representing the Cambrian Series 2-Miaolingian boundary interval. A major erosional disconformity observed in the quarry is interpreted as a 1st order sequence boundary that can be correlated with the base of the När Lowstand in Scandinavia. An exceptionally thick (7 m!) interval of hummocky and swaley cross-stratified sandstones indicates storm deposition during transgressive conditions in the aftermath of that event.