The Sea Retreats, the Sea Returns

Part of Hall of Planet Earth.

The Sea Retreats, The Sea Returns AMNH/R.Mickens

The upper walls of the Grand Canyon reveal sedimentary rock layers formed in marine and continental environments between 550 and 260 million years ago. The Coconino Sandstone layers were deposited by winds in dry periods. As the sea returned, the rock layers of the Toroweap Sandstone were created in sandy coastal environments. Finally, as the ocean encroached, the Kaibab Limestone was deposited in quiet, shallow waters.

Sea and Wind Deposit Process_ILL

In This Section

Windblown Desert Deposit AMNH/R.Mickens

Windblown Desert Deposit

The Coconino Sanstone was formed when desert winds drove fine grains of quartz sands onto the Colorado Plateau, dune by dune.

 

A white-ish rock specimen with a bumpy surface attached on the bottom to a metal post which is attached to a metal base with an exhibition number "19." AMNH/R.Mickens

Calm Marine Deposit

The Kaibab Limestone was deposited as organic carbonate fossil fragments, sand grains, and mud 260 million years ago in a shallow, quiet ocean. The fossil remains of brachiopods and sponges that lived at the bottom of this ocean can be seen in the samples before you.