56 



University of California. 



Vol. i. 



terrace formations, which correspond in altitude to the 300 feet ter- 

 race, repose upon the carmeloi'te lava sheet, and both have been 

 faulted to an extent of at least 20 feet, as is illustrated in Fig. 3. 



A third class of facts, which point to local bending of the strata 

 between the deposition of the earlier and later terrace formations, is 

 well exhibited on the low sea cliffs which back the sand beach about 

 half a mile to the west-northwest of the Carmelo Mission. Here 

 there are seen in the cliff sections two sets of strata, both ascribable 

 to the terrace formations, in unconformable relation. This relation is 

 best seen in the cliffs a few hundred yards north of Abalone Point. 

 Here there is a vertical exposure of 20 feet. The lower half of this 

 section is occupied by rather coarse, unevenly bedded, and little 

 coherent sandstones, with a sparing number of pebbles, which have 

 with little question, been deposited at some little distance offshore, 

 as the equivalent of the coarse, pebbly beach formations of some of 

 the higher terraces. These sandstones have now a southerly dip 

 of 1 5 , and their upturned edges are truncated to a horizontal 

 plane, showing a very fine base-leveled effect. Upon these truncated 

 edges repose in horizontal attitude the terrace formations of the 

 newer and lower 30-feet terrace, to a thickness of 10 feet. These 

 are loose, sandy formations, with many pebbles. 



The same relation is evidenced a few hundred yards still farther 

 north along the shore, where the lower formations are represented 

 by 10 feet of soft sandstone in four distinct beds of about equal 

 thickness. Those beds have a southerly dip of io°, and their edges 

 have also been truncated to a base level of erosion (wave action) 

 before the deposition upon them of sands and gravels of the 30-feet 

 terrace. The truncation of these gently bowed strata evidently 

 took place when the rate of uplift exceeded the rate of accumula- 

 tion of the shore drift in the bay, the 30-feet terrace being here an 

 embankment of drift which was carried into the bay and lodged 

 there, rendering it shallow. 



Age of the Terrace Formations. — If we assume the earlier uplift, 

 which gave to the coast the larger features of its topography, 

 to be the great post-Miocene uplift which affected the whole coast, 

 then it is evident that we have here a record of events covering both 

 Pliocene and Quaternary time. This we believe to be the case. 



