248 



University of California. 



[Vol. 1. 



examples of coast terraces or plateaus sculptured by the action of 

 ice. The stratification is almost perpendicular. . . . The sur- 

 face of the rock seems to have been absolutely planed off, and the 

 different degrees of hardness of the layers in stratification had no 

 apparent influence upon the mechanical forces at work."* This 

 hypothesis of ice action is, as the writer has elsewhere shown,f 

 untenable and entirely unnecessary as an explanation of the origin 

 of the forms. They are simple cases of wave-cut terraces. 



While the lower terraces may thus be followed practically for 

 the entire extent of the coast, and critically examined at close 

 quarters, the higher terraces, for a considerable part of the route fol- 

 lowed by the writer, escape observation, or are only seen in the 

 distance. This is largely due to the following facts: (1) The edge 

 of the coastal plateau is not equally precipitous, and the high ground 

 upon which the upper terraces may be scored is often distant from 

 the shore road. (2) Even where the ascent from the shore to the 

 summit of the plateau is abrupt, the upper portions of the slope are 

 frequently timbered, and, so, much more obscure than the lower 

 portions. (3) The higher terraces being much older have suffered 

 more from degrading forces, and so appeal less strongly to the eye. 

 In many cases they have doubtless been entirely obliterated. These 

 causes conspire to make the evidence of the measure of the uplift, 

 in so far as it depends upon marine terraces, defective for the por- 

 tion of the coast between Greenwood and Ten-mile Creek. Else- 

 where along the coast of Sonoma and Mendocino Counties terraces 

 may be very commonly observed at altitudes which were estimated 

 at various values from 500 to 1,000 feet. No marine terraces of 

 higher elevation were observed; but as the writer disclaims having 

 made any especial effort to find terraces at high altitudes, his inabil- 

 ity to record them counts for little. 



In the extreme northern portion of Mendocino County, at a 

 wind gap overlooking the ocean, about eight miles north of Kenny, 

 water-worn pebbles, well rounded, were observed on a terrace-like 

 bench at an altitude which was estimated to be [,200 feet above the 



* Pacific Coast Pilot, 4th ed. U. S. Coast and Geodetic Survey, Washington, 



1889, p. 272. 



fThis Bulletin, Vol. 1, No. 4. 



