1916 J 



Dickerson : Tejon Eocene of California 



435 



WHITE SHALES 



Mr. John Ruekman studied the white shales overlying the white 

 sandstone member and he found in the shales two faunas, one in their 

 lower portion which is apparently Tejon and another in the upper- 

 most stratum which is apparently Oligocene. The Tejon fauna was a 

 meager one consisting of Trochocyathus, cf. striatus, Crassatellites 

 mathewsonii and some indeterminate forms. A portion of the white 

 shale may represent the Siphonalia sutterensis zone in this region. 

 Indirect evidence supports this view. The fauna from locality 672 

 contains several species which are common in the Siphonalia sutter- 

 ensis zone and their presence suggests that the fauna in the upper 

 portion of the white sandstone member is transitional between that of 

 the Rimella simplex zone and the Siphonalia sutterensis zone, i. e., it 

 may nearly correspond to the Balanophyllia zone of the section south 

 of Mount Diablo. (See figure 10.) 



SUMMARY 



1 The Eocene strata between Domengine and Cantua creeks. 

 Coalinga Quadrangle, belong to the Tejon group. 



2 These strata appear to be equivalent to the Eocene strata in 

 the vicinity of Mount Diablo. They apparently represent a longer 

 portion of Tejon time than the Tejon of the type locality. 



3 The fauna of the lowermost beds which is older than the 

 Rimella simplex zone, the fauna of the type Tejon, is tentatively cor- 

 related as the equivalent of the Turbinolia zone of the Mount Diablo 

 region. 



4 The fauna of the white sandstone member is as a whole the 

 equivalent of typical Tejon, although the fauna from the uppermost 

 beds may be transitional between the Rimella simplex zone and the 

 Siphonalia sutterensis zone. 



Tejon Group in San Diego County 



The fauna of the Tejon group of San Diego County is a par- 

 ticularly interesting one, as it occurs in sediments which have 

 undergone but little folding or faulting. Diastrophism was not so 

 marked in southern California in post-Tejon time as in the central 

 and northern parts of the state. On this account, a correlation be- 

 tween the Tejon of San Diego County and the upper Eocene in the 



