Introduction: The Devonian beneath the oil sands

Devonian strata beneath the oil sands have been acknowledged and studied since the early explorers of the 1800s. The focus on the Devonian shifted from the original emphasis on correlation and age, to evaporite resources in the early to mid-1900s, to stratigraphy of the oil sands underburden in the 1950s and 1960s, and finally to the current emphasis on geohazards and disposal. Devonian and later strata in the oil sands mining area have been impacted by the dissolution of the Prairie Evaporite Formation, a 200+ m thick succession of mostly halite. This special issue on "The Devonian beneath the Oil Sands" presents some of the current research and sets a baseline for future investigation.