Chapter 13 Sverdrup Basin

Abstract

Abstract The Sverdrup Basin is located in the Canadian Arctic Islands. It is 1,000 km by 350 km and is filled with up to 13 km of Carboniferous to Paleogene strata. The basin initially developed in Early Carboniferous as a rift basin upon highly deformed Early Paleozoic strata of the Ellesmerian Orogenic Belt. The development of the basin can be broken into eight phases, each being characterized by a distinctive combination of tectonic, depositional and climatic regimes and separated by episodes of widespread uplift and basin reorganization. The Upper Paleozoic strata are up to 5 km thick and are characterized by a distinct shelf to deep basin topography. Carbonate strata dominated the shelf until Middle Permian and were supplanted by siliciclastics and chert in Middle and Late Permian when the climate cooled. Triassic siliciclastics are up to 4 km thick and they filled the deep, central basin by Late Triassic. From latest Triassic to earliest Cretaceous the basin was occupied by shallow siliciclastics shelves and up to 2 km of strata accumulated. Renewed rifting in Early Cretaceous resulted in a thick succession (2 km) of Early Cretaceous non-marine to shallow marine strata with units of basalts in the northeast. Widespread diabase sill and dyke intrusion, likely related to the Alpha Ridge Plume and the opening of the Amerasia Ocean Basin, occurred at this time. Following an interval of low subsidence and low sediment supply in the Late Cretaceous, the basin began to be deformed in earliest Paleocene by the Eurekan Orogeny driven by the counterclockwise rotation of Greenland. Local foreland basins developed and contain up to 3 km of Paleocene–Eocene strata. In Late Eocene the basin was uplifted and deformed by faulting and folding with deformation decreasing southwestwards. Eighteen oil and gas fields have been discovered in Eurekan anticlines and potential prospects include traps associated with Eurekan structures, salt domes, reefs and prominent unconformities. Widespread petroleum source rocks are documented in Middle and Upper Triassic strata and likely occur with other stratigraphic intervals from Carboniferous to Lower Cretaceous.