28S \V. LINDGREN — TWO NEOCENE RIVERS OF CALIFORNIA. 



divide separating the watershed of the Neocene North fork from that of 



the South fork. There are- several small volcanic areas, sometimes un- 

 derlain by gravel, two or three miles northwest of Auburn near the 

 railroad ; but these are too high to have formed part of the principal 

 channel. Between the small deposit mentioned and Jones hill no trace 

 of the ancient river can be found. 



Grade- : 



Lee mine to Auburn, about 14 miles, 86 feet to the mile. 



Auburn to Jones hill, 9 miles. 63 feet to the mile. 



Jones Hill to Bath. — A great many difficulties present themselves 

 when an attempt is made to reconstruct the drainage southwest of 

 Forest hill. Mr Browne has shown that a large antevolcanic channel 

 enters the Forest hill divide at Bath and, making a large curve, -passes 

 by the Mayflower mine; thence to near Forest hill, where it comes uear 

 the margin of the volcanic cap, hut turns again at the Dardanelles mine 

 and runs in under the lava in a northwesterly direction. 



Another channel enters under the volcanic ridge at Yankee Jim. 

 Whether it connects with the Dardanelles channel is not known. The 

 volcanic ridge continues down to Peckham hill, but only later inter- 

 volcanic channels appear to exist below it. which would seem to indicate 

 that the older channel has in this vicinity been nearly entirely obliterated 

 by those of a later period, if. indeed, it ever followed this direction. 1 

 have provisionally marked the older channel as following the ridge down 

 to Peckhani hill and joining another channel near Yankee Jim. 



The so-called Ponds channel near Todds valley is at too high an eleva- 

 tion to have ever formed a part of the lowest antevolcanic channel, ami 

 should, I think, rather lie considered as a bench gravel deposited after 

 the tilling up of the deepest depression. 



The question of the continuation of the Mayflower and Dardanelles 

 channels is very much complicated by the existence of a detached series 

 of evidently antevolcanic gravel areas to the south of the Middle fork. 

 I have provisionally connected them with a line running from Jones 

 hill, with an elevation of 2.114 feet, by Floris, with an elevation of 2,530 

 feet, up to the channel which near Volcanoville emerges from the volcanic 

 ridge south of the Middle fork.* The deposit at Floris is 14i> feet 

 lower than the main Dardanelles channel in a corresponding position. 

 Any attempt to explain these apparent contradictions would lead too far 

 into the realm of hypotheses. 



It is certain, however, that a channel of some magnitude came down 

 from the highlands of the Georgetown divide, crossed Otter creek at 



- Feral small Neocene tributaries came down toward this line from the Georgetown divide. 



