The Origin and Correlation of the Cloverly Conglomerate

The Cloverly conglomerate is described and correlated with the following formations: the Blairmore conglomerate, the massive Kootenai sandstone of central Montana, the Lakota sandstone, the Beckwith conglomerate, the Ephraim conglomerate, the lower sandstone of the Dakota group of northern Colorado, the Lytle sandstone, the Purgatoire sandstone, and the "post-McElmo" conglomerate. Evidence is offered to show that the Cloverly conglomerate and its correlatives are the oldest Lower Cretaceous formations in the western interior and that they were derived from a mountainous area to the west, which was uplifted during the Sierra Nevada disturbance. Further evidence is given to show that the Kootenai coal measures of southern Alberta and central Montana are of Upper Jurassic age and are closely related to the Morrison formation.