Miospore evidence for the Carboniferous age of rocks from the Świebodzice Unit (Sudetes, SW Poland)

Abstract

The paper provides new results of palynological studies of rocks from the Świebodzice Unit. An abundant Carboniferous miospores were found in rocks of the Pogorzała Formation from the southern part of this unit. These miospores occur in rocks containing also macrofloral and marine macrofaunal fossils, partly reworked, which were usually considered Upper Devonian. Two miospore sub-assemblages of different ages and colours have been distinguished. One of them consists of poorly preserved miospores, dark in colour, which indicate the Late Visean–Serpukhovian age of the rocks. The other sub-assemblage, found only in a few samples, consists of much lighter and well-preserved miospores of the Asturian age. Their presence is considered as a result of stratigraphical leakage. Observation of the miospore colour indicates that the thermal event occurred after the Late Devonian and before the Asturian and the palaeotemperature exceeded ~180°C. These new data indicate that the geological history of the Świebodzice Unit lasted longer  and was much complex than it was previously considered.