undifferentiated rock units

Paleontology and geology

Most of Northwest Territories was above sea level during the Jurassic. A narrow, shallow sea ran along the western side of the territory, while a shallow basin covered some of the Arctic islands in the north. Sediments eroding off the land were deposited in rivers, deltas, beaches, and shallow water environments in these areas. As the continent moved north in the Jurassic, the climate became cooler, and different species of brachiopods, bivalves, belemnites, ammonites, crinoids, and foraminifera could be found in the shallow seas. While many of the rocks from this period have been eroded, there are a few small exposures in the northernmost islands, with more deposits below the surface.