Margaret Formation

The Margaret Formation is an Early Eocene geologic formation in Arctic Canada, within the Eureka Sound Group of the Sverdrup Basin, and exposed on Ellesmere Island. About 140 metres thick and lying above the Mount Moore Formation, it preserves Wasatchian-age fossils in rocks laid down across a delta plain of channels, coal swamps, and coastal deposits. Ash beds dated to roughly 53 million years ago help place it in time. Its greatest significance is the evidence it preserves of a far warmer, wetter High Arctic, with rainforest-like communities and a diverse fauna of mammals, birds, reptiles, amphibians, and fish living much farther north than their modern ranges.

Nunavut · Canada