Smith.] Islands of Southern California. 223 



mon features, notwithstanding the fact that some of the canyons are 

 drowned at their mouths. Wherever bars are formed across the 

 mouths of the minor drainage lines, they are in such positions that 

 they might readily be destroyed on elevation. 



The Los Angeles embayment forms a marked exception to the 

 rest of the California coast. During post-Pliocene times this was, 

 at certain stages, a very shallow and extensive bay, with gentle 

 off-shore slopes, furnishing especially favorable conditions for the 

 formation of wave- and current-built features. Further, owing to 

 the width of this great embayment, and the gentle slopes of its 

 floor, the conditions since elevation are favorable to the preserva- 

 tion of any such features. 



On the Redondo and adjacent sheets of the Topographic Atlas 

 of the U. S. Geological Survey are seen what appear to be two 

 extensive wave- or current-built embankments or series of embank- 

 ments, within the Los Angeles embayment. One of these extends 

 northward, along and near the coast, from the northern slopes of 

 San Pedro Hill, for a distance of about eleven miles, when it turns 

 to the east, running inland for about four miles, to join an elevated 

 isolated mass southwest of Los Angeles. The structure is not 

 simple, but consists of two distinct, parallel ridges, broad, flat- 

 topped and mesa-like, separated by a series of slight depressions. 

 Of these two ridges, the one nearer the coast has an average alti- 

 tude of 150 to 175 feet, while the average altitude of the other is 

 about 125 feet. The average width of the entire structure is about 

 two miles. 



The other structure referred to lies at a distance from the coast 

 for the greater part of its length. It begins at the north about five 

 miles east of Santa Monica, and extends, as a low and broad ridge, 

 southeasterly across the entire Los Angeles embayment, a distance 

 of about forty miles. In its course and near its northern end 

 (southwest of Los Angeles) lies the isolated elevation already 

 referred to, the height of which is 517 feet. From this hill the ridge 

 runs to the present shore at Anaheim Landing, about ten miles 

 east of San Pedro Hill. From this point its course is along the 

 shore to Newport Bay, at the southern end of the Los Angeles 

 embayment. The ridge has an average width at its base of, 



