l62 CALIFORNIA ACADEMY OF SCIENCES [Proc. 30 See. 



ever, there are two structural ox-bow curves, one on either 

 side of Coalinga at a distance of some ten or more miles, in 

 which the Cretaceous rocks are carried well toward the val- 

 ley, forming the foundation upon which the Tertiary oil 

 yielding strata are deposited. 



Attention should be directed to these curves as structural 

 features of the range as a whole, but too little is yet known 

 of them to warrant more than a suggestion. It appears that 

 their repetition along the eastern part of the range forms the 

 axes of local anticlines in the later strata which plunge 

 respectively below the level of the valley bottom. No less 

 than six such folds are known between the Sunset district 

 and the Big Panoche Creek north of Coalinga, but their 

 fuller discussion must be left for another time. 



Eocene Formations. 



The Eocene strata of the Coalinga district and vicinity lie 

 in detached belts alongr the eastern and northeastern flanks 

 of the range. One of the more extensive belts of Eocene 

 rocks extends from the northern border of the Sunflower 

 Valley westerly to the head of Alcalde Creek. Another 

 begins in the hills west of Coalinga and extends northerly 

 for two miles or more and includes the coal mines of that 

 district. A third belt begins north of Los Gatos Creek, 

 extends northeasterly along the foothills, and can be traced 

 north and northwesterly in a fairly well marked band for 

 twelve or fifteen miles to Salt Creek, and thence westerly 

 to Silver Creek and the Panoche Valley. Northward from 

 Los Gatos Creek the Eocene forms a fairly uniform and 

 continuous series as far as it has been followed. 



Still another area occurs on the northern border of the 

 Antelope Valley near the Devil's Den, and includes the 

 massive sandstones at the place locally termed the Point of 

 Rocks. A fifth and more southerly area of Eocene occurs 

 in the near vicinity of Temblor and at Canara Springs and 

 northward toward the Antelope Valley. At Canara Springs 

 the massive sandstones of the Eocene form conspicuous and 

 picturesque cliffs, over which lie the more regular beds of 



