EVIDENCE FOR A SOUTHERN EXTENSION OF THE WEGENER FAULT IN NARES STRAIT, ARCTIC CANADA (Invited Presentation)

The sinistral Wegener Fault in Nares Strait, which separates northwest Greenland and eastern Ellesmere Island (Canadian Arctic), represents a tectonic element in the Arctic, whose existence and significance have been controversial for more than 50 years. Some workers interpret the Wegener Fault as an important Early Paleogene transform related to movements of the Greenland plate relative to the North American plate. Others view it as insignificant or reject its very existence. Onshore studies in the Canadian portion of the northern Nares Strait region have proved the existence of important sinistral strike-slip faults related to the offshore Wegener Fault. The southern continuation of the Wegener Fault is unclear. In particular, Smith Sound has been interpreted as a location of undisturbed continuation of the Proterozoic basement from Greenland to Ellesmere Island.

Our structural studies along the west coast of Smith Sound and adjacent areas of eastern Ellesmere Island suggest a three-stage tectonic evolution. Stage 1 is a brittle deformation (ca. NNE-SSW sinistral strike-slip faults, partly with a conjugate dextral set) that took place under ca. NW-SE shortening. Structures of this deformation are assigned to the Paleocene and can be related to the Wegener Fault in the offshore area of Smith Sound. Following uplift and subsidence during normal faulting (Stage 2 deformation) and younger contractional deformation under ca. NE-SW shortening (strike-slip faults, partly as conjugate sets) of Stage 3 deformation affected the Paleogene deposits. Stages 2 and 3 can both be assigned to the Eocene.

The overall interpretative picture points to a protracted deformational history in the Paleocene to Eocene, which partly interfered with the deposition of clastic sediments. The first deformational stage in the Paleocene is related to an active system of sinistral strike-slip faults related to the Wegener Fault. Therefore, the existence of this fault system in the southern Nares Strait region, east of the eastern Ellesmere Island coast in Smith Sound, is inferred.