GEOLOGIC HISTORY 223 



as is shown by occurrences of these formations in the 

 Mecca Hills and by later movements of 3,000 feet along 

 north-south rifts to the west and as seen in the north 

 bench of the San Gorgonio Pass. The two move- 

 ments which brought about these conditions were of 

 post-Pliocene (Pleistocene) Age. 



2. The master faults of the later northwest and 

 east-west systems cut across strata of Pliocene age in 

 manj^ places, as, for instance, in the La Canada, Los 

 Angeles, Ventura and Puente districts and where the 

 San Jacinto Fault cuts across the vertebrate fossil- 

 bearing Badlands strata. 



3. The Ventura Ranges include Pliocene strata in 

 their up-turnings, hence some of the folds and faults 

 are, in part, of post-Pliocene or Pleistocene Age. 



4. The San Andreas Rift which, according to 

 Noble, may have originated as far back in time as 

 the Mesozoic cuts across Miocene and Pliocene strata 

 along the San Bernardino escarpment and in San Gor- 

 gonio Pass. I estimate that the San Bernardino 

 Plateau, as a whole, has been elevated from 3,000 to 

 5,000 feet in Pleistocene time. 



5. The folded strata of the City Hills in Los An- 

 geles are largely made up of Pliocene strata and hence 

 the age of the folding is post-Pliocene, or Pleistocene. 

 A typical fold of Pliocene strata may be seen along 

 Alvarado street on either side of First street in Los 

 Angeles. Parts of folds can be viewed in exposures on 

 Fifth street opposite the entrance of the Public Li- 

 brary, at First and Hill streets, and elsewhere. The 

 strata at the Library site contains fossils of latest 

 Pliocene (Saugus) Age, as has been determined by 

 others. Hence we must conclude that the miniature 



