Smith.] 



Islands of Southern California. 



195 



Goodyear* states that more than three-fourths of Santa Cruz 

 consists of volcanic material. 



The stream courses of Santa Cruz are well developed and 

 numerous, and many of them show evidence of submergence at 

 their mouths, in the formation of small bays. These flooded stream 

 valleys are more numerous than in the case of Santa Catalina. 



Nothing is known to the writer concerning possible terracing 

 on Santa Cruz. From the character of the topography it is 

 probable that, if any terraces do occur, they are not well-developed. 



The chief characteristics of the second group of islands are: a 

 rugged topography; a drowning of many of the stream valleys 

 (when they are of sufficient size and development) at their mouths; 

 an absence of pronounced terracing, which does not preclude, 

 however, some evidence of such features, where comparatively 

 gentle slopes have been exposed to vigorous wave action; and, in 

 the case of Santa Catalina and Santa Rosa, at least, a planation of 

 the summits at an approximate altitude of 1,500 feet. 



The Small Islands. — Two islands remain unclassified, — Anacapa 

 of the northern group, and Santa Barbara of the southern. 



Although Anacapa is composed of three small islands, these 

 are hardly to be separated, as they lie in a nearly straight line, with 

 very narrow channels between them. They are usually, therefore, 

 considered as a single island. The group has a length of about five 

 miles, and a maximum width of a little more than half a mile. 

 West Anacapa is the largest, and rises to a height of 980 feet. 

 The chief features of the group are the abrupt cliffs on the south, 

 rising nearly or quite to the summits of the islands, with gentler 

 slopes toward the north. The cliffs are nearly continuous on all 

 sides, but lowest on the north. The rocks of Anacapa are volcanic, 

 according to Dr. L. G. Yates. f 



According to Davidson's description and sketch,.} Anacapa is 



*Calif. State Mining Bureau, 9th Ann. Rept. for 1889, p. 155. 



tCalif. State Mining Bureau, 9th Ann. Rept. for 1889, pp. 171-174. 



JThe Abrasions of the Continental Shores of Northwest America, and the 

 Supposed Ancient Sea Levels, Proc. Calif. Acad. Sci., Vol. V, 1873-74, p. 93. 

 and Plate V. 



