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University of California. 



[Vol. i. 



this earth. These terraces have but a very scant soil or are bare 

 rock, and the cliffs which rise abruptly from the horizontal line at 

 their rear are commonly beetling crags, so steep as only to be 

 clambered over with great difficulty and at favorable places, while 

 in many places they cannot be scaled. The slope of the terraces is 

 always seaward at a low angle, and upon the rocky floors there may 

 be observed occasional isolated conical crags, rising twenty, thirty, 

 forty, or fifty feet above the terrace at some distance out from the 

 base of the cliff precisely analogous to the "stacks" which project 

 through the surf from the littoral shelf of to-day. The breadth of 

 these great terraces ranges commonly from 200 to 1 ,500 feet, and 

 the height of their cliffs from 50 or 60 to 300 feet. Water-worn 

 pebbles are sparingly strewn over the surface of the terraces, but 

 probably not more sparingly than along the present strand, where 

 water-worn pebbles and bowlders are only abundant at exceptional 

 localities, such as Seal Cove, where the shore drift lodges and accu- 

 mulates. It is frequently obvious that the excessive recession of 

 some of the sea-cliffs has resulted locally in the obliteration of one 

 or more terraces above them, so that the plots of transverse pro- 

 files, at half-mile intervals, say, would show many important dis- 

 crepancies, owing to the dropping out of a certain terrace in this 

 profile, two other terraces in that, and so on. The extent and 

 breadth of the terraces, and the vertical dimensions of their sea- 

 cliffs, are so great that they appear as very striking features on the 

 United States Coast and Geodetic Survey's manuscript map of the 

 island, scale jyj-uy, contour interval forty feet. But, although the 

 terraces and cliffs are very apparent on the map, it is not possible to 

 read off, with even approximate precision, the altitude of the base 

 of the cliffs, owing to the large vertical interval employed in the 

 contours.* 



*In 1863 Dr. Cooper, as zoologist to the Geological Survey, visited San 

 Clemente, observed the terraces and appreciated their significance. His 

 observations are given by Whitney in the "Geology of California," Vol. 1, p. 184. 

 He says: "Its form is that of a terraced table; and although from the nature of 

 the rock and the scarcity of shells but very few fossils have been preserved, yet 

 there is sufficient evidence that each one of the terraces, of which there are 

 about seven, has been at one time the beach of the island. . . . The eleva- 

 tion of the highest terrace was estimated at 1,000 feet." This brief statement 



