Cordell Bank Geology

June 2017

Several miles off the shore of Northern California lies an underwater gem: Cordell Bank National Marine Sanctuary Watch our video to discover what makes this colorful habitat so lush.


Marine life in Cordell Bank National Marine Sanctuary thrives in part due to its geological features.

The granite bedrock was once part of the Sierra Nevada mountain range until movement in the Pacific tectonic plate sheared the granite bedrock into its present location off the coast of Point Reyes, California.

The bank is still moving at a rate of five centimeters each year.

Invertebrates flourish here, thanks to large rock formations and shallow waters where they can attach.

The sandy channels throughout the bank provide a historical record for life and are a great place for scientific research.

In fact, the sand isn't really sand at all but is composed of shell fragments and calcium carbonate deposits from the animals that used to live there.

The unique blend of oceanic conditions and geological topography allow Cordell Bank National Marine Sanctuary to thrive.