Sequential Restorations from the Sverdrup Basin: New Insights for its Mesozoic Evolution

The Sverdrup Basin is a northeast-southwest trending depocentre located in the central to north-western parts of the Canadian Arctic Islands. It contains anomalously thick (13 km) Carboniferous to Late Cretaceous strata when compared with surrounding areas (e.g. Arctic Alaska). The mechanism for creation of this accommodation space is poorly understood as deformation associated with the Eurekan Orogen obscures any potential structures related to the formation of the basin. The prevailing view is that the basin was initiated during the Mississippian as a result of the gravitational collapse of the Ellesmerian Orogen. Most of Late Carboniferous to Cretaceous time was characterised by different periods of extension interspersed with periods of tectonic quiescence, both of which were accompanied by the rising of salt diapirs from the Carboniferous Otto Fiord evaporites. The latest Cretaceous to Paleogene was characterised by shortening related to the Eurekan Orogeny.

This work presents cross-sections of the Sverdrup Basin, which have been sequentially restored in order to highlight its Mesozoic to Cenozoic structure and the effects of the Eurekan Orogeny. These cross-sections, additionally, illustrate the development of diapirs during the different Mesozoic phases of rifting and tectonic quiescence. The cross-sections are grounded on field data collected by CASP and on data found in the literature.

Constraining the timing of fault movements and diapirism is important because of the insights it can provide into the palaeogeography of the Canadian margin of the Canada Basin and therefore into the evolution of the Amerasia Basin. Additionally, salt-related structures in the Sverdrup Basin have the potential to contain hydrocarbons