Deciphering superimposed Ellesmerian and Eurekan deformation, Piper Pass area, northern Ellesmere Island (Nunavut)

Abstract

The tectonic evolution in the Piper Pass area in northern Ellesmere Island (Canadian Arctic) is characterized by the superimposition of two major deformational events: the Paleozoic Ellesmerian Orogeny and the Tertiary Eurekan deformation. It is difficult to separate the structures formed during each deformation in the parts of the Canadian Arctic in which the post-Ellesmerian and pre-Eurekan Sverdrup Basin is not preserved (Hazen Fold Belt, Central Ellesmere Fold Belt). In the vicinity of the Lake Hazen Fault Zone in the Piper Pass area, kilometre-scale kink folds, cleavage planes and SSE-directed thrust faults are unconformably overlain by Permian through Tertiary rocks of the Sverdrup Basin, which clearly indicates that they are related to the Ellesmerian Orogeny. However, the steep faults of the Lake Hazen Fault Zone are characterized by possible lateral movements and by NNW–SSE compression that cut through or affect both the pre-Ellesmerian Franklinian strata, as well as the post-Ellesmerian Sverdrup Basin deposits. These structures can clearly be assigned to post-mid Cretaceous movements of the Eurekan deformation. The Piper Pass area is a key area in which it is possible to recognize and distinguish Ellesmerian from Eurekan structures.