Paleontology and geology

Most of Manitoba was above sea level and exposed to erosion throughout the Jurassic. Deposition was restricted to lakes, river valleys, and lowlands. The reddish-colored sandstones in the southwest of the province preserve some of these continental deposits. In the Middle to Late Jurassic, marine waters encroached over the continent from the northwest, reaching the southwestern corner of Manitoba. Exposures of sandstone, limestone, shale, and evaporites in this area record beach, lagoon, and shallow marine environments.