1913] 



Louderback : The Monterey Series 



215 



has thus originated more than once in the application of this 

 name." Nevertheless it may be pointed out that Anderson no- 

 where gives a characteristic fauna for his "Monterey shale" 

 and really makes the division on lithologic grounds himself. 

 In fact the fossils which he reports from the Monterey shale are 

 the same that are found in the diatomaceous shale which he first 

 called Monterey but which in his later paper he placed in the 

 Eocene or Oligocene because he considered that it lay uncon- 

 formably below sandstones carrying a Temblor fauna. 



We find here again an unrealizable ideal system of two for- 

 mations, two faunas, two periods of deposition — and an actual 

 condition of the lithological division of a series dependent on 

 depositional facies varying from place to place in relative thick- 

 ness. 



Geological History of Coast Ranges, Lawson, 1908. — In this 

 same year in the Report of the State Earthquake Investigation 

 Commission" 2 on the California earthquake of April 18, 1906, 

 Lawson outlined briefly the geological history of the Coast 

 Ranges. Without discussing the ideas of others he showed that 

 his view of the unity of the Monterey series had been unaffected 

 by the numerous publications that had dismembered it and given 

 its parts and different areas various names and interpretations. 

 He says "Miocene time in the Coast Range region was charac- 

 terized by a progressive subsidence with oscillations of the coast. 

 The Miocene sea gradually transgrest the continental margin 

 from the southwest, and as it did so spread a formation of arkose 

 sands and conglomerates over the greater part of the Southern 

 Coast Ranges. This was followed, as the water deepened with 

 progressive subsidence, by a remarkable deposit of bituminous 

 shales" (p. 9). 



He notes the oscillatory nature of deposition in the Bay of 

 San Francisco region (giving 9 divisions instead of the 7 he 

 previously reported — 5 sands and 4 bituminous shales). "This 

 series is known as the Monterey series." "While the oscillation 

 of the coast so clearly recorded in the strata near the Bay of 

 San Francisco is not apparent in the southern Coast Ranges, 

 it is by no means certain that they were not affected in a similar 



«2 Carnegie Inst, of Wash., vol. I, Part I (]908). 



