Kane Basin, Nares-Strait: Strike-slip induced sediment deformation along the coastline of Ellesmere Island

Abstract:

The nature of the Nares-Strait (NS), a seaway between Greenland and Ellesmere Island, is important to understand the plate tectonic history of the Arctic region. As it is clear that rifting and seafloor spreading took place between Greenland and Baffin Island, it is unclear how the extension was compensated between Greenland and Ellesmere Island. Already Alfred Wegener suggested some kind of left lateral transform fault along the NS, a straight seaway separating the Greenland Plate from the North American Plate, nowadays proposed as the Wegener-Fault. Plate tectonic reconstruction models require a transform fault for the compensation of several hundred km of extension and seafloor spreading from Late Cretaceous to Eocene times. However, land geological data do not support this thesis and let assume that no lateral displacement occurred between Greenland and Ellesmere Island. With the formation of the recent Midatlantic Ridge System between Greenland and Europe since the early Eocene, the western branch became inactive and consequently the proposed transform fault, too. Northeast motion of Greenland replaced the left lateral transform and caused compression. The inactive transform fault was overprinted and as a consequence it was altered, probably displaced and is difficult to recognize.

The Kane Basin is one of a series of basins that are aligned along the NS. It resembles probably a pull-apart basin following the approach that NS developed as transform fault.

This paper presents insight into the Kane Basin by means of 2D seismic data, sonobuoy data, gravity and magnetic data acquired during surveys of BGR in 2001 and 2010. The eastern Kane Basin is characterized by a deeper rim and a more shallow central part. Most of it is floored by Proterozoic crust without any sediment on top of it. Only in the western part of the Kane Basin a sedimentary infill can be recorded which terminates with an erosional truncation on to the seafloor. Because of the mapped sediment and fault pattern, a pull-apart development of the Kane Basin can’t be supported. However, the steepening of the sedimentary beds towards Ellesmere Island and anticlinal deformation parallel to the NS point to the presence of a strike-slip fault that runs parallel to the Ellesmere Island coastline.