Denver Museum of Nature & Science
Ancient Denvers
 
Exhibition
Landscapes
Formations
Behind the Scenes
Park Partners
Links & Resources
Ancient Denvers Home
DMNS home

Submarine Colorado
70 million years ago (Late Cretaceous)

Sea water
Find the clickable hot spots for details and evidence, or follow the links below. (Click to see larger image)

Description: Colorado is literally at the bottom of the sea—not a mile high, but a tenth of a mile deep! The nearest shoreline is hundreds of miles to the west. Here and there, the surface of the water is broken by the spouts of air-breathing marine reptiles. In other places, schools of fish are chased to the surface, drawing the attention of soaring pterosaurs. But landing on the water can be dangerous in a sea full of sharks, toothy fish, and mighty marine lizards known as mosasaurs.

Formation: Pierre Shale

Artist: Donna Braginetz

Best Viewing Spots:

  • Rooney Road near Dinosaur Ridge
  • Garden of the Gods Park and Visitor Center
  • Fountain Creek Nature Center
  • Valmont Dike

Rooney Road
The Pierre Shale is a relatively soft rock, so it rarely forms outcrops. This roadcut on Rooney Road south of Golden is a place where the Pierre Shale has been tilted from its original horizontal orientation to a nearly vertical position. You can see thin, resistant ledges of sand. When this was a muddy seafloor, the thin layers of sand were deposited during storms.


< earlier in time later in time >

back to top

© 2002 DMNS. All rights reserved.