456 



STRUCTURAL GEOLOGY OF NORTH AMERICA 



TEMBLOR RANGE 



SIERRA NEVADA FOOTHILLS 



Fig. 29.5. Generalized section across the southern 

 Section K-K', Fig. 29.1. 



sic. The Santa Lucia Range, most of the Santa Cruz Mountains, and much 

 of the Diablo Range stood above sea level, as did also the central Sierra 

 Nevada. 



The middle Eocene sea appears to have had a much wider extent and 

 to have flooded much of the San Joaquin embayment. The middle Eocene 

 formations are recognized by Taliaferro (1943b) to be the Capay, Do- 

 mengine, and lone. They are sandstones, shales, clays, limestones, and 

 coal beds; and they are unusually fine grained except at the margin of 

 the border lands. The lone is clearly of an eastern source, but the Middle 



San Joaquin Valley. After Hill and Eckis, 1943. 



Eocene along the Diablo Range contains detritus from the Franciscan 

 and Cretaceous strata of the ancestral Coast Ranges as well as the crys- 

 talline rocks of the ancestral Sierra Nevada. The Middle Eocene covered 

 the east flank and northern end of the Diablo Range, probably a part of 

 the Santa Cruz Range, and northeastern part of the Santa Lucia Range. 

 Minor volcanic activity can be recognized by rhyolitic and andesitic debris 

 in the lone of the Great Valley, supposedly of an eastern source in the 

 Sierras, and by bentonite in the Domengine of the Coast Ranges, sup- 

 posedly of a western source ( Taliaferro, 1943b ) . See accompanying chart. 



