REVIEWS. 235 



The present writer dissents radically from the author's fundamental 

 conclusions and from his estimate of the present drift of opinion, but 

 finds the book interesting and suggestive, and its contributions to Pleis- 

 tocene paleontology notably valuable. T. C. Chamberlin. 



The Post-Pliocetie Diastrophism of the Coast of Southern California. By 

 Andrew C. Lawson. Bulletin of the Department of Geology, 

 University of California Vol. i, No. 4, pp. 1 1 5-160, plates 8-9. 



In this bulletin, Professor Lawson presents the results of some of 

 his studies on the west coast of California. The essay concerns itself 

 especially 1° with the coasts of San Diego and Los Angeles counties, 

 and with the islands of San Clemente and Santa Catalina which lie 

 a few miles to the west ; and 2° with the coastal region from Santa 

 Cruz to the Golden Gate. So far as concerns the southern region, 

 the data are drawn principally from four localities. These are : a) the 

 coastal slope of San Diego county, — the San Diego mesa; b) San 

 Pedro Hill ; c) San Clemente Island ; d) Santa Catalina Island. 



The San Diego mesa is a terraced plain having a breadth of from 

 twelve to eighteen miles. It is characterized as a Pliocene delta, made 

 up principally of Pliocene sands and sandstones, but covered by a 

 thin sheet of river gravels. The evidence for the statement that these 

 gravels are of fluviatile origin is not given. The gravels are thought 

 to have been deposited approximately at sea level. They now stand 

 at a maximum elevation of nearly eight hundred feet. The inference 

 is that an elevation of eight hundred feet has taken place along the 

 coast of San Diego county since Pliocene time. Various marine ter- 

 races at levels of seven hundred feet and less characterize the mesa. 



San Pedro Hill is an abrupt headland on the coast of Los Angeles 

 county. Its slopes likewise show a series of marine terraces and sea- 

 cliffs. The highest terrace on this headland stands at an elevation of 

 1240 feet. There are many lower terraces on the San Pedro Hill, the 

 lowest mentioned having an altitude of 120 feet. Through the higher 

 terraces the streams have cut for themselves canons ; but they flow over 

 the lower terraces in shallow channels. This is evidence of the recency 

 of the elevation marked by the lower terraces. Molluscan borings in the 

 old sea-cliffs, up to an elevation of 1240 feet, may still be seen. 



From the relations of the Miocene to the Pliocene formations of 

 the headland, it is inferred there was an " important interval of denu- 



