1914] 



Dickerson: Faunal Zones of the Tejon Group 



V.) 



The following section through Cave Point was measured by Mr. 

 William Kew and the writer. Figure 1 shows the relations graph- 

 ically. 



Section op the Tejon Group South op Mount Diablo 



Chico sandstone and limestone Feet 



(1) Conglomerate 5 



(2) Thin-bedded gray sandstone 20 



(3) Gray foraminiferal shale 75 



(4) Hard gray sandstone 40 



(5) Massive tan sandstone 20 



(6) Gray-green foraminiferal shale 25 



(7) Light-tan coarse sandstone with cavernous weathering, first bluff 125 



(8) Alternating soft sandstones and carbonaceous shales 200 



(9) Sandstones with interbedded shales 307 



(10) Thin-bedded sandstone 50 



(11) Shale with thin-bedded sandstone 63 



(12) Thin-bedded sandstone with Turritella uvasana beds on top 100 



(13) Massive soft sandstone with Turritella uvasana beds, second bluff 100 



(14) Massive tan sandstone, second bluff 390 



(15) Shale 100 



(16) Light gray sandstone 8 



(17) Carbonaceous shale and thin-bedded sandstone 45 



(18) Massive tan sandstone, third bluff 554 



(19) Carbonaceous shales and lignite 25 



(20) Massive tan sandstone 85 



(21) Blue shale 25 



(22) Massive tan sandstone 225 



Monterey sandstone 



Total 2572 



The Tejon on the south side of Mount Diablo is on the average 

 about 2600 feet thick and it has a general strike of N 60° W. In the 

 northwestern portion of the area under discussion, it has a dip of 

 60° south in Pine Canon. Going southward along the strike, these 

 strata become vertical and finally overturned in the vicinity of Cave 

 Point, where they have a dip of 70° to 85° N. Two to three miles 

 southeast of Cave Point the Tejon is pinched out by a great over- 

 thrust fault. Very extensive collections were made throughout the 

 entire extent of the Tejon. A particularly good section for study 

 was found in an unfaulted area lying between Cave Point and Oyster 

 Point. At least three faunal zones were recognized in this area. 



