♦ 



1 8 University of California. [Vot. i, 



while the surface is smooth, it is not even, as may be seen in Plate 3. 

 There are low, rounded, lumpy portions, and the surface has in 

 places a domed aspect, as is further illustrated in Plate 2, Fig. 2. 



There is thus no shadow of doubt as to the intervention of a 

 long period of erosion between the solidification of the granite and 

 the deposition of the conglomerates and sandstones of the Carmelo 

 series. As these are the oldest sedimentary rocks in the district, it 

 is certain that the granite underlies the whole of the sedimentary 

 series as a basement, and the notions which have become current of 

 the intrusion of the granite into the Miocene are utterly erroneous. 

 Indeed, the direct superposition of the shales of the Monterey series 

 (Miocene) upon the worn surface of the granite maybe as indubita- 

 bly observed as in the case of the Carmelo series. That the granite 

 is anterior to the eruptive rocks is also proved (1) by the fact that 

 bowlders of the granite have been caught up and imbedded in them, 

 (2) by an inspection of the immediate contact of the two rocks, 

 which may be observed at two good exposures, and (3) by their inter- 

 section of the Carmelo series, rich in bowlders of the granite. The 

 granite is thus the oldest rock on this part of the coast, and if, as 

 has been suggested, the Carmelo series is of Eocene age, the gran- 

 ite is certainly pre-Tertiary. But farther north, across the Bay of 

 Monterey, in the Santa Cruz Range, the granite, without doubt of 

 the same geological age as that of the Santa Lucia Range, bears a 

 similar basal relation to rocks which are of not later age than 

 Cretaceous. The erosion which truncated the Santa Lucia granite 

 was, therefore, largely completed in pre-Cretaceous time, and the age 

 of the granite is at the latest pre-Cretaceous. 



THE CARMELO SERIES. 



Petrography. — The rocks of the Carmelo series are prevailingly 

 thick-bedded conglomerates of dark color, and thinly-bedded 

 tawny sandstones. There is also a subordinate proportion of shale 

 and shaly sandstone. The conglomerates are most abundant at the 

 basal portion of the series, but also alternate with the sandstones 

 throughout the entire thickness. The pebbles in the conglomerates 

 are usually not large, averaging in the great mass of the formation 

 from one to four inches in diameter, and in general resemble stream 



