UPPER CRETACEOUS OF THE PACIFIC COAST

Rocks of Late Cretaceous age osccur on the Pacific Coast of North America from Baja California, Mexico, to the Queen Charlotte Islands of British Columbia. The standard term Upper Cretaceous series is adopted for these deposits instead of the often widely and variously misused term Chico series (or “group” or “formation”), and Chico is applied only to those sediments on the east side of the Sacramento valley from whose occurrence on Chico Creek the term was derived. The series is best represented in the Sacramento and San Joaquin valleys of California where rocks of Cenomanian to Maestrichtian ages are recognized...