1913] 



Louderback: The Monterey Series 



225 



"In this member clays and shales probably form in the out- 

 crop about 50 per cent of its volume, and of this percentage about 

 one-half is organic. Some layers are chiefly composed of diato- 

 maceae and other minute organisms" (p. 92). 



He gives fossil lists as collected from three "zones," A, B, 

 and C, and these lists include forms already familiar on the west 

 side. "As will be seen the faunas of the three prominent zones 

 already described belong to the lower division of the Neocene, 

 and are characteristically Lower Miocene. The upper division 

 as far as known is almost without fossils, and is barren of any 

 forms that are serviceable for stratigraphic correlation" (p. 102). 



As for the lowest zone (A). "It was at first thought that this 

 horizon might prove to be older than the typical Temblor, on 

 account of the number of large pecten species it contained, but 

 there is now quite abundant proof that a horizon older than the 

 Temblor has not been recognized either here or in any part of 

 the Temblor basin. ... It may be supposed that the occupation 

 of the Temblor basin by the sea was transgressional and pro- 

 gressive and that there are older beds belonging to the Neocene 

 in the outer coast ranges ; but if this is true it has yet to be 

 shown" (p. 107). 



In regard to zone B, he said "Any question which may arise 

 as to its exact stratigraphic position is more likely to involve 

 only a choice between the Temblor and the Monterey. But thus 

 far in the study of the West Coast Miocene, the Monterey has 

 not been regarded as the habitat of such species as Agasoma 

 graviclum, Turritella ocoyana, Cythcrea mathewsoni, Dosinia 

 whitneyi, Yoldia impressa and a score of other species given in 

 the lists. . . . And furthermore it must be added that while 

 Zone B is rich in species, some of which have often been found 

 in the Monterey shales, the species most widely characteristic 

 of the latter, namely Pecten peckhami, has not been found at all 

 in any part of the Kern River area" (p. 107). 



It is hard to see how this is a point against its "Monterey" 

 age, seeing that P. peckhami has been found farther west in 

 rocks lying below the "Vaqueros" or "Temblor" and considered 

 by Arnold, R. Anderson, F. M. Anderson and others, Eocene or 

 Oligocene, as well as in the latest "Monterey shales." It can 



