Abstract

Cretaceous to Paleogene sedimentary deposits are widespread across the eastern Canadian Arctic and similar rocks occur also in Greenland and Spitsbergen. These rocks, most of which in Canada are called the Eureka Sound Formation, are the product of closely related regional orogenic events and are markedly similar in lithology and age.

Intensive study in the Bay Fiord region of west-central Ellesmere Island shows that the Eureka Sound Formation there is readily divisible into four informal members. These represent a gradual change in depositional environment from shallow marine to fluvial, although a marine transgression is documented in the middle of the sequence. The lower three members can be traced throughout central Ellesmere Island, which probably is a single depositional basin. The upper member is known to occur only in the Bay Fiord area, and has produced the only terrestrial Paleogene vertebrate fossils known from the Arctic. Areas geographically remote from Bay Fiord are not correlated with the Bay Fiord sequence, except imprecisely, based on fossil plant remains.

The name Eureka Sound Foundation has been broadly applied throughout the Canadian Arctic. It is unlikely that all the clastic sedimentary rocks at present included in the formation actually belong to one depositionally continuous unit. However, current usage of the Eureka Sound Formation is clearly understood, and at the present level of understanding the concept of this formation is a suitable one for rocks of a uniform and persistent lithologic facies.