Lawson.] 



Geology of Carmelo Bay. 



27 



commonly credited hypothesis may be more searchingly tested and 

 made to show what truth there is in it, before it passes over into 

 the sacred domain of accepted scientific fact. 



Massive Equivalents of the Volcanic Ash. — The lava correspond- 

 ing to the supposed ash of the Monterey series would doubtless be 

 a very acid rhyolite, rich in soda. Such a rhyolite in the form of a 

 dead white, massive rock occurs at Berkeley, as a flow mantling the 

 eroded surface of the Cretaceous rocks, and overlaid by gravels, 

 which are perhaps Pliocene. This Berkeley rock has been investi- 

 gated by Mr. Charles Palache, and he finds it to be a soda rhyo- 

 lite.* Now a very interesting fact is that pebbles of precisely the 

 same rock as the soda-rhyolite at Berkeley are found in abundance in 

 the ancient delta of the San Jose Creek at all elevations up to 620 

 feet above sea level. These pebbles prove that a massive rock cor- 

 responding in chemical character to the shale which constitutes the 

 Monterey series exists in place somewhere in the hills which are 

 drained by the San Jose. Neither the occurrence at Berkeley, nor 

 that at the mouth of the San Jose, exceeds in elevation the summit 

 of the Monterey series, and both occurrences may possibly have been 

 submarine, for all that we know to the contrary. 



Fossils. — Characteristic Miocene fossils have been found in the 

 Monterey series at various parts of the coast by former observers, 

 and in particular at the town of Monterey. These fossils are the 

 warrant for the correlation of the series as Miocene. In addition 

 to the various forms noted in the Geology of California, and in the 

 Pacific Railway Reports, some fossils were found by us near 

 Carmelo Bay which were submitted to Prof. W. H. Dall, who 

 kindly examined them, and identified them as follows: — 



Area sp. (Nov.?) 



Saxidomus sp. 



Leda sp. (Nov.?) 



Lucina, like L. Crenulata. 



Clementia ? sp. 



Young Cardium, or small Venericardia. 

 Pecten (Pseudamusium) Peckhami, Gabb. 

 Macoma sp. (Nov.?) 



*See Bull. Dept. Geol. Univ. Cal., pp. 60-70. 



