145 



The schist cropping out on the sea floor may correlate 

 with the Catalina schist assxuning that the equivalent to the 

 San Onofre breccia never was deposited on top of the Catalina 

 schist in this area or that the schist breccia (or conglomerate) 

 has been almost completely removed by erosion. Since the 

 schist outcrop on the sea floor is a topographic high now, and 

 probably was a high area when it was buried during Miocene 

 time, it may be reasonable to assume that no significant 

 quantities of fragments of schist could accumulate » Fragments 

 of schist that might have broken off during weathering prior 

 to burial would have acctmiulated in low areas, but a few 

 fragments of schist might have been incorporated into the 

 overlying shale » 



Although the difference in geologic time between the 

 Catalina schist and the San Onofre is very great, sedimentary 

 rocks of Miocene and more recent ages frequently rest directly 

 on the basement rock„ Therefore, whether the schist dredged 

 from the outer shelf is basement rock or its weathering product 

 is not too important. 



Rocks in the El Segundo oil field located approximately 

 one mile east of Hyperion range in age from Recent to Jurassic (?). 

 Pliocene and post-Pliocene age rocks having an aggregate thick- 

 ness of 5,700 feet are composed largely of alternating sands 

 and shales, except the lower 450 feet which is composed of shales 

 alone. Sediments of Pliocene age are underlain conformably by 

 1 5,300 to 2,000 feet of Miocene shales. The basal section of the 

 Miocene is made up of a nodular shale, and a schist conglomerate. 

 The Catalina or Franciscan (?) schist of Jurassic (?) age 



