The Sverdrup basin in the Queen Elizabeth Islands of northern Canada contains many piercement structures with exposed cores of gypsum and anhydrite. Several cores are more than 10 square miles in area. Adjacent anticlines may have unexposed evaporite cores. 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. Salt is not known to be associated with these evaporites but its presence is suggested by gravity data.

Piercement structures in the western part of the basin are long, domal, and exhibit little or no evidence of tangential compression; they are probably salt domes resulting from halokinesis or geostatic loading. Ordovician salt is known to exist in the Cornwallis fold belt which presumably extends under the basin; it may have been involved in the early history of piercement structures in the central part of the basin.

In the eastern part of the basin some piercement structures 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.

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