Stonewall Formation
The Stonewall Formation is a stratigraphic unit of Late Ordovician to Early Silurian age in the Western Canadian Sedimentary Basin.
It takes the name from Stonewall, Manitoba, and was first described in the Stonewall quarry by E.M. Kindle in 1914.
Lithology
The Stonewall Formation is composed of finely crystalline dolomite, with a basal argillaceous and sandy dolomite. Two thin sandstone beds occur in the middle and at the top of the formation.In the central Williston basin, the base is marked by an anhydrite bed.