Issues

Cover Photo: An ortho-photogrammetric projection of the Cretaceous McMurray Formation outcrop at Crooked Rapids. The model is a composite of several hundred photographs. The bottom section of the outcrop displays the Athabasca River’s edge, along with the Devonian limestones from the Waterways Formation, on which the McMurray Formation unconformably rests. The lower sandstones exhibit high-angle cross-stratification, sharply overlain by sandstones interbedded with mudstones. The upper part of the model displays finer-grained strata, belonging to the Cretaceous Clearwater Formation. See Hayes et al., this issue.