UNIVERSITY OF CALIFORNIA. 



Bulletin of the Department of Geology. 



Vol. 2, No. 7, pp. 179-230. Plate 5. ANDREW C. LAWSON, Editor. 



A TOPOGRAPHIC STUDY 



OF 



THE ISLANDS OF SOUTHERN CALIFORNIA.* 



BY 



». 



W. S. Tangier Smith. 

 CONTENTS. 



Page. 



Introduction ....179 



Grouping of the Islands 180 



Description of the Islands with Simple Topography 184 



The Rugged Islands...., 189 



The Small Islands 195 



Submarine Features 196 



Coastal Topography 205 



Development of Wave-cut Terraces 208 



Preservation of Elevated Wave-cut Terraces 216 



Wave and Current-built Features 219 



Drowned Valleys 224 



Historical Sketch 226 



Introdziction. — The islands off the coast of southern California 

 furnish an unusually interesting field for physiographic study, 

 both on account of the isolation of the individuals, and on account 

 of the pronounced variation of form presented. This paper points 

 out and discusses the causes of their principal variations, giving, 

 at the same time, a brief outline of their most recent movements, 



*The following paper was first prepared for publication in April, 1897, but 

 was withheld for various reasons, the chief of which was the author's desire to 

 give more careful study to the subject than had been possible at that time. 

 He has not yet had opportunity to make such further study in the field as he 

 desired, but after a careful review of all the facts at his command, he feels 

 that the paper should be presented as it stands, leaving the corroboration or 

 disproof of his views to future investigation. The paper was read in abstract 

 at the December (1899) meeting of the Geol. Soc. Am., Cordilleran Section. 



