584 well logs and 139 cores have been used to establish a two-part stratigraphy for the Viking Formation in the area of the Caroline and Garrington reservoirs, Alberta. The lower part consists of a northeastward-prograding coastal succession of offshore and shoreface storm deposits, capped in places by nonmarine facies. This succession is dissected by a regionally-extensive transgressive surface of erosion (TSE) that rises stratigraphically southwestward (landward). It has at least 15 m of relative relief and is mantled by a transgressive lag of sandstone and conglomerate averaging 1-2 in thick (maximum 8 m). The upper stratigraphic unit consists of marine black shales with five tongues of coarse sandstone and conglomerate, each 1 --3 m thick. These have previously been interpreted as tidal sand ridges but a tidal interpretation is very difficult to reconcile with the presence of thick interbedded black marine shales. Correlation of well-log and core cross sections suggests that these coarse tongues converge toward (and are interpreted to onlap) the underlying transgressive lag toward the southwest; they are not coarse bodies completely isolated in marine mudstones. The tongues do not have a ridge morphology. We interpret the tongues as extensions of the lower shoreface, formed during minor regressions interspersed with the main transgression. At these times of lowered sea level, the coarse sediment was transported seaward by storms and/or tidal currents and deposited abruptly on top of black mudstones. Thus the coarse reservoir rocks appear to result from forced regressions, which are in turn controlled by high-frequency oscillations of sea level.