28 



University of California. 



[Vol. 3. 



If I am correct in considering the San Pedran epoch as 

 approximately equivalent to the Iowan of Eastern States geology, 

 a considerable interval of erosion is due between the San Pedran 

 and Glacial epochs. I know of no particular set of valleys or of 

 deposits so characteristic of that epoch as to deserve to give it a 

 name, and I will merely recognize its existence, leaving it 

 unnamed for the present. 



The present flood-plains of all the streams in the lowland 

 areas of Southern California mark the Modern epoch. South of 

 the Sierra Madre Range, as in the San Fernando Basin, there are 

 some large alluvial fans not much removed in character from the 

 ordinary "detrital slope" type, whose upper portion belongs to 

 this latest division of the Quartenary era. It appears also that 

 there has been a slight subsidence of the coast and certain of the 

 outlying islands in this Modern epoch as discussed by Lawson,* 

 Fairbanks, !" and Smith. I 



SUMMARY. 



The conclusions expressed in the preceding pages as to the 

 Quaternary history of Southern California and the provisional 

 scheme of classification proposed for it may be briefly summar- 

 ized into the following table : 



Quaternary Era 



Recent 

 Period 



Modem 

 Epoch 



Deposition 



Land Level 

 Below Normal 



Length 

 Ratio 5 



Pleistocene Period 



Glacial 

 Epoch 



Not 

 represented 



Not known 



5 



LeUonte's Sierran Period 



Not named 



Erosion 



Normal 



10 



San Pedran 

 Epoch 



Deposition 



Below Normal 



5 



LosAngelan 

 Epoch 



Erosion 



Normal 



75 



Red Bluff 

 Epoch 



Deposition 



Below Normal 



10 



1 



Santa Claran 

 Epoch 



Erosion 



Normal 



890 



*Bull. Dept. Geol., Univ. Calif., vol. 1, No. 4, pp. 138-139. 



tAmer. Geol., vol. XX, Oct., 1897, pp. 236-237. 



J Bull. Dept. Geol., Univ. Calif., vol. 2, No. 7, p. 226. 



