Notes on the Jurassic of Southwestern Saskatchewan
Four Jurassic formations are recognized in southwestern Saskatchewan—the Watrous, Gravelbourg, Shaunavon, and Vanguard. Since the type sections of these formations were first established, additional drilling has made it advisable to redefine the three members of the Vanguard formation.
The four formations are described briefly and attempts are made to illustrate the correlation between them and the Sawtooth, Rierdon, and Swift formations of the Ellis Group of Montana.
The difficulties experienced in determining the Jurassic-Cretaceous boundary are illustrated by means of several cross sections.