6 



University of California 



[Vol. i. 



stretches of wnite sandy beach. There are excellent examples of 

 wave erosion in the numerous coves and clefts near Carmelo Point, 

 and in the sub-aqueous shelf which runs out from the base of the 

 cliffs. 



The water deepens more rapidly off shore in the southern part 

 of the bay than in the northern. 



GENERAL STATEMENT OF THE GEOLOGY. 



The eroded surface of a granite mass forms the basement upon 

 which rest the sedimentary formations. On the shores of the bay 

 this granite is the most prominent rock and excellent exposures are 

 afforded which permit its petrographical character and its relations 

 to the other formations of the locality to be described with precis- 

 ion. The rock has prevailingly a coarsely porphyritic facies, the 

 phenocrysts of orthoclase ranging commonly from one inch to three 

 inches in length. This granite, in the vicinity of Carmelo Bay, is 

 in easily traceable continuity with the extensive granite mass which 

 forms the main ridge of the Santa Lucia Range to the southward. 

 It will therefore be referred to in this paper as the "Santa Lucia 

 granite." The Santa Lucia granite is traversed, not only at Carmelo 

 Bay but elsewhere in the range, by small dykes of a finer-grained 

 generally feebly porphyritic granite and also by small dykes of 

 coarse pegmatite. These dykes had traversed the Santa Lucia 

 granite prior to the erosion which truncated the mass and prepared 

 the surface upon which the sedimentary rocks now rest. 



Reposing upon the worn surface of this granite is a series of sand- 

 stones and conglomerates, with some argillaceous shales. This series 

 has a thickness of several hundred feet. Locally it has been much 

 disturbed and sharply folded into vertical attitudes, and has been 

 sunk down bodily into the granite, it being apparent that the relief 

 from strain which was effected in the sandstone by folding, was 

 effected in the underlying granite by faulting and shearing. This 

 series has yielded no fossils at Carmelo Bay, but it appears to be 

 identical with the coal-bearing sandstones of Malpaso Canon, about 

 two miles distant. The latter are believed, from the occurrence in 

 them of heavy beds of fairly good coal* and from such fragments 



*Turner in his admirable paper on the Geology of Mount Diablo states that 



