Halite formations of Canada for clean energy storage (hydrogen, CAES): A geologic review

Solution-mined salt caverns are in versatile use for large-scale storage-withdrawal of petroleum products (collectively underground gas storage—UGS), as well as novel applications essential for transition to net zero carbon economy: hydrogen gas (UHS) and compressed air energy storage (CAES). We present the first comprehensive Canada-wide review of bedded and halokinetic halite formations suitable for cavern storage. Such halites occur at depths of ~200-2000 m in the industrially developed regions (Fig. 1): Western Canada sedimentary basin (WCSB) in the Prairie provinces; Salina Group in Ontario; and in the Maritimes sedimentary basin (the Gulf of St. Lawrence and onshore mostly in New Brunswick, Nova Scotia, and Newfoundland). The Devonian salt beds of WCSB are undeformed, and the size of caverns is limited by thickness of halite beds (40-100 m, maximum 200 m). There are 196 caverns in Alberta and Saskatchewan, most of them active. In Ontario, Salina Group halite beds are of variable thickness with complex, dissolution-controlled outlines. This region counts 142 active and historical caverns. The Maritimes Basin is a “saline giant” with thick Mississippian-age halites forming diapirs and walls. Several gas storage prospects were recently launched in the Maritimes, most notably in southern Newfoundland. Underexplored and untapped potential for salt caverns exists in frontier regions: the northern WCSB where Cambrian halites were partly involved in halokinesis to form walls and diapirs, in Hudson Bay depocenter (undeformed Devonian halites), and in the Canadian Arctic Archipelago where salt tectonics had formed domal structures potentially suitable for large (> 1 Mm 3 ) caverns.