The Coniacian-Santonian Muskiki and Marshybank formations of the Alberta Foreland Basin were deposited on a ramp margin, which lacked a distinct shelf-slope break. The rocks are entirely clastic and have been divided into 14 facies ranging from silty clay through sandstone to conglomerate. Weakly bioturbated siltstone may have been deposited in relatively deep, oxygen deficient water, over 100 km from shore. In contrast, sideritic, bioturbated siltstone, sandy siltstone and silty sandstone were deposited closer to shore on a fully oxygenated shelf. Hummocky cross-stratified inner shelf sandstone extends about 30 km seaward of massive swaley cross-stratified and parallel-laminated fine sandstone that represent a shoreface. Large, shore-normal gutter casts are common in these sandy shelf facies. In the far northwestern part of the study area, coarse sandstone rich in chert pebbles is also interpreted as representing a shoreface setting, adjacent to a major river mouth. Nonmarine sediments include crossbedded fine to medium grained sandstone that forms lensoid and epsilon cross-stratified channel sandbodies. These sandbodies are enclosed in rooted, organic-rich, grey, green, and black siltstone interbedded with silty sandstone, interpreted as floodplain and lake deposits. Abundant pyrite suggests that these "nonmarine" facies may have been deposited in brackish water. Eighteen outcrop sections and two cores have been correlated using a regional subsurface stratigraphic framework. Depositional units (parasequences) in outcrop can also be traced regionally in well logs. Well logs allow determination of gross lithology (shoreface sands versus offshore deposits) and hence permit regional mapping of paleoshorelines. Four discrete periods of shoreface progradation are recognized; these involved between 70 and 115 km of progradation. Each shoreline was orientated broadly north-northwest-south-southeast; localized protuberances may reflect the position of wave-dominated deltas. In offshore (> 100 km) areas, storm waves approached from the north and associated geostrophic bottom flows were directed parallel to shore, toward the south-southeast. In more nearshore areas, waves were refracted parallel to shore and oscillatory scour generated abundant shore-normal groove and gutter casts. Well constrained lateral and vertical facies successions permit synthesis of facies distribution within an "ideal" parasequence. Facies may be grouped into transgressive, highstand, and lowstand systems tracts, which can be related to a sinusoidal relative sea level curve.
