214 University of California Publications in Geology [Vol. 7 



sent, it seems certain that the organic shales at some points 

 represent part of the earlier half of the period, and the sand- 

 stones or terrigenous shales represent part of the later half at 

 other points. 



Coalinga-McKittrick Region, F. M. Anderson, 1908. — In 1908 

 F. M. Anderson 110 published "A Further Stratigraphic Study in 

 the Mount Diablo Range of California," dealing particularly 

 with that part of the range between Cantua Creek and McKit- 

 trick. He used the same terms for the rocks under discussion 

 as he did in his former paper, the "Temblor beds" and the 

 ' ' Monterey shale. ' ' He considered the Temblor to be the more 

 persistent of the two and also "best characterized by fossils, and 

 is therefore the most easily recognized faunally" (p. 18). Their 

 usual thickness is given as 450-550 feet. The Monterey shale 

 is said to be 5000 feet thick north of the Temblor ranch house 

 and to decrease to 250 or 300 feet near Coalinga 01 (the "Big 

 Blue" of the oil men doubtfully referred by Anderson to the 

 Monterey. 



Anderson again criticized very strongly (pp. 38-39) the use 

 of the term "Vaquero sandstone" because the "type" locality 

 (Los Vaqueros Valley) lacked "faunal or even stratigraphic 

 description," nor is it delineated on any published map. He 

 admits, however, that "most of the strata that have been de- 

 scribed under the name 'Vaquero sandstone,' as far as known, 

 represent a well characterized horizon of the Lower Miocene, and 

 as such are without doubt to be correlated with the Temblor beds 

 of the Mount Diablo range" (p. 39). 



As to the siliceous shales, "the Monterey shales occurring 

 in the Middle Miocene of California have generally been called 

 by that name; hence little is to be said regarding their corre- 

 lation with the same in the Mount Diablo range. In general, 

 however, there is a tendency to trust too far to lithological char- 

 acters in their identification, and it is not unlikely that error 



so Calif. Aead. Sci. Proc, 4th Ser., vol. 3, pp. 1-40 (1908). 



si In his earlier publication (see loc. ext., p. 207 of this paper) some of 

 the beds evidently belonging to the Monterey series were included in his 

 "Coalinga beds," but in this paper they are removed from that category 

 and placed with the Temblor, and the term Coalinga is therefore not here 

 discussed. Diatomaceous shales near Coalinga in the previous paper re- 

 ferred to the Monterey are in this paper called Eocene or Oligocene. 



