8 



University of California. 



[Vol. 2, 



ful hollow casts of a number of species of shells. The most of them 

 could not be determined, although Crepidula rugosa, Nutt, and a 

 Pupiira were recognized. The Pleistocene mesa is broadest a little 

 east of Wood's Creek, where it is undergoing the peculiar "bad 

 land" erosion often seen in strata of this age along the coast (Fig. 

 i). It is very similar to the Pleistocene capping of Point Loma, 

 in the southern part of the state, even to the presence on the sur- 

 face of small concretionary nodules formed of sand cemented by 

 iron oxide. The mesa forms an even encircling rim about the 

 Miocene hills at an elevation of 950 to 1,000 feet, and extends 

 down the transverse ridge east of Wood's Creek to an elevation of 

 500 feet. 



It would appear that this post-Pleistocene elevation is probably 

 identical with that noted at other points along the coast. 



On the south side of the Point Sal ridge, between the Old Land- 

 ing and the Point, is a narrow strip of land, sufficiently flat to be 

 cultivated, and known locally as the Mesa. Its upper edge has an 

 elevation of a little over three hundred feet. It is composed of 

 stratified sand and fragments from the steep mountain above. 

 Whether it can be correlated with the Pleistocene just described is 

 not certain. 



Elevated Beaches. — The records of at least four different ocean 

 levels besides the present were recognized on Point Sal, the highest 

 being that of the Pleistocene mesa, reaching an elevation of 1,050 

 feet. The next one has an elevation of only about 1 1 5 feet, and 

 was distinguished along the banks of the first creek emptying into 

 the ocean east of the Chute. It consists of a bed of washed gabbro 

 boulders. What is probably the same shore line is rather indistinctly 

 shown on the seaward face of the Lion's Head. It would be very 

 pronounced if it were not for the crumbling of the cliff above. The 

 two lower terraces are most distinctly marked in the diabase cliff 

 west of the Old Landing. The narrow mesa before referred to, 

 overlies them at one point, and it is due to this fact that they are so 

 finely preserved. The lower one has an elevation of 25 feet, the 

 upper of 80. Both form well-marked benches in the diabase, with 

 washed boulders at their upper limits, above which the cliff in each 

 case rises almost vertically. The stratified sands and gravel of the 



