i 5 6 



University of California. 



[Vol. i r 



Whichever may have been the outlet — which at present is closed up 

 — it is, perhaps, difficult to decide now; but the valley everywhere, 

 especially at the lower end (north), presents the usual marks of run- 

 ning water in the terraces found on its mountain sides, and on such 

 a large scale as to induce the examiner to look upon the whole plain 

 as once an extensive lake, the level of whose waters were then 200 

 feet above the present level of the plain below. . . . The pres- 

 ent river flows about four to six feet below its bank; the bottom o^ 

 the river forms an alluvial flat about a mile in breadth ; on each side 

 of this a higher plain, the more ancient bottom, extending for a mile 

 on each side, and about twelve feet higher than the true bottom. 

 This ancient bottom reaches to the foot of the mountain ranges. 

 Thirty feet high on the San Jose Mountains a terrace is found, which 

 may be traced for several miles north and south; the line of the ter- 

 race is not horizontal, but apparently falls to the southeast; this may, 

 however, be only apparent, as the level of the plain slopes in the 

 opposite direction. Opposite to this, near the camp at Quadre 

 Domingo, the terrace on the sandstone of the Santa Lucia is about 

 the same height, and is covered with pebbles of red and green con- 

 glomerate, quartz, and porphyry. That on the San Jose is white 

 clay and sand rock in angular fragments, with pebbles of the opales- 

 cent quartz found underlying the ostrea bed of Santa Margarita. 

 Above the terrace line is that one first described. The order of all 

 these would lie thus": — 



The terraces thus described by Antisell afford us no direct means 

 of estimating the uplift which they record. It is a bare possibility, 

 even, that they may be due simply to the drainage of a lake by the 

 trenching of a barrier. But, taken with the other facts as to the 

 recent elevation of the coast, it seems probable that they are to be 

 ascribed to the same general cause as in the other cases described. 

 If, as Antisell maintains, the ancient outlet has been choked, and a 



Total elevation 

 above sea, in feet. 



Terrace 100 to 150 feet high on mountain .... 



Terrace 30 feet high on mountain 



Terrace 12 feet high, old river bottom 



Terrace, present river bottom, river 4 feet below 



1,690 



1.542 

 1,512 

 1 , 500 



