Geol.— Vol. II.] ANDERSON— STRATIGRAPHIC STUDY 167 



On the N. E. ^4^ of Sec. 17, north of Coalinga, similar 

 pebbly beds just above the top of the Kreyenhagen Shales 

 contain a few of the foregoing species along with species of 

 Foraminifera and nodules of barites. 



This horizon of the Eocene begins its greater development 

 at this point and increases in thickness as it is followed to the 

 northwest. On the east side of Section 17 it has a thickness 

 of not more than three hundred fifty feet, while eight miles 

 to the northwest it has a thickness of something like twelve 

 hundred feet, where it is exposed in the vicinit}' of the Kim- 

 ball wells. 



It consists chiefly of yellow sands, which, as far as they 

 have been followed, are but little consolidated, and under 

 the meager rainfall of the region readily disintegrate, forming 

 loose sandy slopes. Its great development in the vicinity of 

 the Domijean ranch affords grounds for its designation as 

 the Domijean Sands. 



On the west side of Section 17 the sandy beds at the base 

 of the Eocene aggregate somewhat more than at the coal 

 mine, but they are also more distributed stratigraphically, 

 with shales intei"vening between their several layers. 



They are partially represented on Plate xxxiv, figure 3. 

 Their correlation with the Avenal Sands is based chiefly 

 upon tlieir stratigraphic position, as they are undoubtedly 

 basal and rest directlv upon the concretionary Chico sand- 

 stones. 



In the vicinity of New Idria and along the southern side of 

 the Big Panoche Valley the Eocene rocks present the stratig- 

 raphy characteristic of the series north of Coalinga. Three 

 members are clearl}- distinguishable, though their aggregate 

 thickness can hardly exceed twelve hundred feet. The beds 

 may be divided as follows : 



ft. 



Loose ash-colored sandstones 300 



Carbonaceous clay shales 300 



Sandstones (ash-colored) 600 



Total 1200 



The Eocene age of these beds appears to have been at 



