Lawson.] 



Geology of Carmelo Bay, 



7 



of fossils as could be found, to be of Tejon (Eocene) age. This 

 series of sandstones and conglomerates on Carmelo Bay is therefore 

 entatively held to be Eocene. In order to avoid giving a positive 

 character to this correlation and for general convenience in descrip- 

 tion, these rocks will be designated in this paper the "Carmelo 

 scries." 



The Carmelo series was folded and subjected to erosion before 

 the deposition of the next higher series — the Miocene. The reasons 

 for this statement are the very evident differences in the extent to 

 which the two series have been disturbed, and the fact that the sand- 

 stone of the lower series has been locally removed from the granite 

 so that the Miocene rocks rest directly upon it. The Miocene for- 

 mations are abundantly developed but do not extend down to the 

 shores of the bay. The margin of the terrane has in part retreated 

 by reason of erosive action, and in part has been covered by later 

 formations, so that the line of exposure is about a mile distant from 

 the shore. The series was among the first which attracted the atten- 

 tion of the earlier writers, Trask* and Blake,* and it has since 

 become famous for the "infusorial" remains which it contains, being 

 known to collectors as the Monterey formation. This name, under 

 the form of the "Monterey series," will be adopted as the local des- 

 ignation of the series. It is richly fossiliferous, not only at certain 

 horizons in diatoms and radiolaria, but also generally in calcareous 

 forms (foraminifera) and locally in molluscan and other remains. 

 The formations which constitute the series are mostly light colored, 

 usually white or cream-colored or yellowish, and have a soft chalky 

 character. There are also some calcareous and some harder, com- 

 pact opaline beds. Up to the present the white or cream-colored 

 chalky portions of the formation have been described as essentially 

 a formation of infusorial earth. Our observations cast some doubt 

 upon this idea and show that at best it is only partially true. The 

 characters of the formation seem to correspond rather to a volcanic 

 ash (modified) than to an organic deposit. And siliceous organic 

 remains form only a very subordinate proportion of its constituents 



the coal-bearing strata of Mount Diablo and of Central California generally are 

 of Tejon age. Bulletin G. S. A., Vol. 2, p. 392. Whitney also earlier held the 

 same view. See Geology of California, Palaeontology, Vol. II, p. xiii. 

 *Op. cit. 



