Rockridge Geology and the nearby Hayward Earthquake Fault:

by James K. Sayre

As its name implies, the Rockridge District of Oakland, California is on a foundation that is at least partially rock. The Hayward fault crosses through the Oakland foothills about one mile east of the center of the Rockridge district.

The geology of Rockridge is obviously a small part of the larger Oakland area geology, which in turn is part of the East Bay geology.

Geology is the science that studies rocks, soils and the structures and forces that have molded the earth historically over billions of years to produce the present earth that we live on. Rocks are basically divided into three types: sedimentary, igneous and metamorphic. Sedimentary rocks are basically those that have been formed by deposition underneath oceans. Igneous rocks result from volcanic activity, while metamorphic rocks are those that result from the heating and compression over long periods of time of the first two types of rocks.

Personally, I admit to never having much interest in the subject of geology, although my parents had a pretty large rock collection, which after we kids grew up, they donated to the science department of the local high school.

I defer to a comprehensive book entitled, A Natural History of California by Allan A. Schoenherr, published by the University of California Press in 1992. It includes extensive discussions of the geology of California and also discusses earthquakes and earthquake fault lines.

End.

Bottlebrush Press has maintained its presence on the Internet since 1996.

Return to the home page of Bottlebrush Press: The homepage of Bottlebrush Press

This web page was recently created by James Sayre.

Author's Email: sayresayre@yahoo.com

Copyright 2005 by Bottlebrush Press. All Rights Reserved.

Web page last updated on 23 February 2005.