Middle Permian U–Pb zircon ages of the “glacial” deposits of the Atkan Formation, Ayan-Yuryakh anticlinorium, Magadan province, NE Russia: Their significance for global climatic interpretations

The Atkan Formation in the Ayan-Yuryakh anticlinorium, Magadan province, northeastern Russia, is of great interest because of the occurrence of deposits of apparent “dropstones” and “ice rafted debris” that have been previously interpreted as glacial. Two high-precision U–Pb zircon ages, one for an intercalated volcanic tuff (262.5 ± 0.2 Ma) and the other for a boulder clast (269.8 ± 0.1 Ma) within a diamictite of the Atkan Formation, constrain...