Cenozoic–Mesozoic stratigraphy of the Nova Scotia shelf has been subdivided into three groups, twelve formations, and four members on the basis of subsurface information from approximately twenty offshore wells. The oldest stratigraphic unit recognized is salt, possibly of Early Jurassic age. The salt occurs in several sub-basins, where it is generally overlain by a conformable sequence of dolomite, anhydrite, limestone, and shale. Poorly sorted, feldspathic, clastic sediments disconformably overlie the evaporite sediments and adjacent basement rocks composed of metasediments and granite.The Western Bank Group consists of limestones and associated shales, which were deposited during widespread marine transgression. Marine sediments are in turn overlain by, and in part equivalent to, several thousand feet of Jurassic and Cretaceous sandstones and shales of the Nova Scotia Group. Sand deposition gradually waned in late Cretaceous time and the shelf was completely submerged. The overlying Gully Group of shales, thin limestones, chalk, and argillaceous sands was deposited in water depths ranging from bathyal to neritic. The Cenozoic section was finally truncated during a pre-glacial period of erosion.