Geol.— Vol. I.] SMITH— SANTA CATALIiYA ISLAND. 9 



Sea Cliffs. — Except for the openings formed by the canon 

 mouths, cHffs surround the island on all sides, running from 

 one or two hundred feet to 1,400 feet or more in height. 

 The boldest and highest cliffs are found at the west end, and 

 between Silver Canon and the southeastern extremity of the 

 island. The highest of all are just to the east of Silver 

 Cafion, where the waves have cut across the end of a minor 

 ridge whose altitude equals that of the main ridge. These 

 cliffs, although furnishing excellent geological sections, are 

 wholly inaccessible at nearly all points, owing to their height, 

 the angle at which they meet the water, and the absence of 

 beaches. 



The cliffs are rapidly receding, in many cases more rapidly 

 than the streams which trench their surfaces can cut down 

 their channels. This is shown by the V-shaped openings 

 on the face of the cliff, from 50 to 200 feet or more above 

 the water. Such are the mouths of the canons draining the 

 southern slopes of the main ridge at the head of Avalon 

 Canon. These open on the southern coast, about two miles 

 to the east of the entrance to Silver Canon. The rapidity 

 of the cliff-cutting here will appear the more remarkable 

 when it is known that these streams, though draining com- 

 paratively small areas, are torrential in character. It must, 

 however, be remembered that they are active only during 

 the rainy season.^ 



In addition to these larger V-shaped openings, several 

 smaller ones were seen along the higher parts of the cliff, 

 less than a mile to the east of the entrance to Silver Canon. 

 These, from the water side, present the appearance of a 

 stream draining outward over the face of the cliff. From 

 above, however, it is seen that the drainage is inland, toward 

 Silver Canon. This phenomenon is due to the cutting back 



'A phenomenon similar to that above described has been observed by the writer at 

 several points along the California coast between Port Harford and Santa Monica. Here 

 the recent streams have carved narrow channels in the surface of the lowest terraces 

 which border the shore, and have formed clear-cut V's on their upper edge. The cause 

 here (unlike that in the case of Santa Catalina) is, no doubt, that an insufficient time 

 has elapsed, since the elevation of the coast, for the streams to deepen their channels 

 further. 



