ABSTRACT

The Sverdrup Basin in the Queen Elizabeth Islands of the Canadian Arctic Archipelago contains many piercement structures with exposed cores of gypsum and anhydrite. Several cores are more than 10 square miles in area. The basin is about 700 miles long and 250 miles wide. It is filled with more than 40,000 feet of Mesozoic clastic deposits underlain by possibly 5,000 feet of Pennsylvanian and Permian sediments including reefoid carbonates and an evaporite sequence.

Piercement structures in the western part of the basin are large, domal, and exhibit little or no evidence of tangential compression; they are probably salt domes resulting from halokinesis or geostatic loading. Some of the piercement structures in the eastern part of the basin are large and domal, but most are relatively small, elongate, and associated with major faults. These appear to have resulted from diapirism initiated by tangential forces during the Laramide orogeny.