This geological cross section (Plate I, in pocket) extends easterly from the British Columbia boundary through northern Alberta and into the western part of Saskatchewan and has been drawn to illustrate the regional structure and stratigraphy across northern Alberta. The section shows a wedge of sediments lying on pre-Cambrian basement rocks. The thick part of the wedge is at the Alberta-British Columbia boundary and the pinchout edge in western Saskatchewan, where Devonian sediments are in contact with the pre-Cambrian shield. Among the features shown on the section are: the general eastward thinning of formations; faults in the Peace River area and their influence on pre-Pennsylvanian formations; a Devonian reef and its association with a basement “high”; and an evaporite basin bordered by reef rocks.

The cross section has been drawn principally for the benefit of those not familiar with the geology of northern Alberta. For this reason tabulations have been added indicating the general lithology of the many rock units illustrated in the cross section. The tabulations also contain other features which are self- explanatory. In addition, the cross section is useful for the general correlation of Cretaceous formations in northeastern and northwestern Alberta.