Palaeokarst evidence for widespread regression and subaerial exposure in the middle Katian (Upper Ordovician) of Baltoscandia: significance for global climate.
We report on widespread and contemporary palaeokarst in the middle Katian (Upper Ordovician) of Sweden, Estonia and Latvia, the first major palaeokarst horizon to be reported from the Ordovician of Baltoscandia. The solution features occurwithin a fewmetres of thick zone of limestone immediately belowthe widespread Fjäcka Shale and are related to an unconformity with preserved palaeorelief in the