Abstract

In the Kicking Horse Pass area, Gog sediments are mainly interbedded quartzite and shale with rare, thin conglomerate. The dominant facies has trough, planar and tidal bundle cross-bedded (0.3 to 2 m thick) quartzite, with thin (0.5 to 8 cm) shale interbeds. The secondary facies has parallel-stratified quartzite and lensen- or flaser-bedded quartzite and shale. Thick (1 to 3.5 m) lateral accretion deposits occur and sequences are poorly developed. Unimodal paleoflow patterns occur in trough cross-bedded facies toward the base of the section, bimodal paleoflows with planar cross-bedded quartzite occur in the middle of the section, and bimodal-to-random paleoflow patterns occur at the top of the section. This corresponds to an increase in the proportion of massive and parallel-stratified quartzite. The interbedded quartzite and shale at the base and middle of the section have a Cruziana ichnofacies, with high diversity and low to moderate density, reflecting the resident ichnocoenosis in a shallow sublittoral setting. The massive quartzite at the top of the section has a Skolithos ichnofacies, with a low diversity and high individual density, characteristic of high-energy substrates. The Gog sediments comprise a 110 m thick shoaling-upward sequence from trough and planar cross-bedded quartzite of offshore dune-sandwave complexes, generated by tidal or littoral currents. This is succeeded by high-energy massive and parallel-stratified quartzite with associated Skolithos ichnofacies, suggesting a near-shore setting. The offshore sandwave complexes have paleotopography and facies associations similar to the Lower Cretaceous “ridge-and-swale” deposits recognized in sub-surface reservoirs of Alberta. Significant is the lack of sequence development in the Gog sediments in comparison to these younger Mesozoic sediments.