Figure 24.11 Outcrop sections. Measured sections from the southern and central foothills illustrating the variability of facies due to climatic differences. The southern foothills strata were deposited in an arid environment, giving rise to widespread caliche and redbeds, whereas strata in the central and northern foothills were deposited in a more humid environment, leading to widespread development of coal. Belly River Formation and the five distinct shoreface facies decreasing in age from southwest to northeast. Structure contours in Saskatchewan, east of the Bow Island Arch, reflect the influence of the Williston Basin to the southeast and salt solution collapse structures in the underlying Paleozoic.
Contours indicate a relatively constant gradient of thickness west of the Bow Island Arch.
Immediately to the east of the arch isopach values increase dramatically. Variability of thickness in southern Saskatchewan can be attributed to the influence of the underlying salt-solution structures. Note the abrupt thinning of the Belly River wedge over the axis of the Bow Island Arch. Figure 24.17 Isopach map of the Bearpaw Formation. The Bearpaw Formation pinches out to the northwest and thickens markedly immediately south of Calgary.