228 



J. F. XEWSOM — CLASTIC DIKES 



The present paper describes a number of sandstone dikes in San Luis 

 Obispo and Santa Cruz counties, California, to which the writer's atten- 

 tion was called by Dr J. C. Branner in 1901. The notes on which the 

 paper is based were made by the writer in the summer of 1901 and the 

 spring of 1902. 



A paper, describing a number of the intrusions occurring in Santa Cruz 

 county, was read and illustrated b}^ lantern slides by Doctor Branner and 



Figure 1.— Skeleton Map of California. 



Showing areas in which sandstone dikes have been described. 1 is the area in which dikes 

 have been described by Diller; 2 is the San Luis Obispo County region; 3 is the Santa Cruz 

 region ; 4 is the Stanford University locality; 5 is the Corral Hollow localitj'. 



the present writer before the Geological Section of the American Associa- 

 tion for the Advancement of Science at the Denver meeting in 1901. 



The locations of the areas described, as well as those localities in Cali- 

 fornia in which sandstone dikes have been formerly described b}^ Diller 

 and others, are sliown on the accompanying skeleton map of California 

 (figure 1). 



