Classic dikes have been of interest and have been regarded somewhat as anomalies ever since the origin of igneous dikes became fixed in the minds of geologists. This fact is made apparent by a review of the literature concerning the dikes of sedimentary materials described in various parts of the world. Most of such dikes are small, and were they of igneous materials would scarcely call for remark.
The present paper describes a number of sandstone dikes in San Luis Obispo and Santa Cruz counties, California, to which the writer’s attention 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 by lantern slides by Doctor Branner and the present . . .