278 W. LINDGREN — TWO NEOCENE RIVERS OF CALIFORNIA. 



As a possibility, he mentions in another part of the volume* that the 

 Red Dog channel may have found an outlet along the present Green- 

 horn river in a southwesterly direction. 



The first question to be disposed of is whether or not there is a con- 

 tinuous channel between Dutch Flat and Indiana hill with a southward 

 grade, as Mr Pettee thinks. It is admitted that there is a deep channel 

 coming down along the Dutch Flat diggings, and that the elevation of 

 this is 2,848 feet at Thompson hill. A short distance south of this. 

 Squires canyon crosses the gravel area connecting Dutch flat and Indiana 

 hill at an elevation of about o,050 feet, or 200 feet above the bed-rock in 

 the low channel of Thompson hill. Regarding the place Mr Pettee f says 

 that "Where the gravel range is crossed by Squires canyon the country 

 rock is seen on each side with a width of about 500 feet of gravel and 

 tailings in the bottom of the canyon. How much more slate was visible 

 before the accumulation of gravel began it is not easy to determine, but 

 it appears as if the slate did not extend entirely across " . . . The 

 result which I reached after two careful examinations was that the bed- 

 rock does extend entirely across the supposed gap, and this effectually 

 disposes of any deep channel connecting Dutch Flat and Indiana hill. 

 The slate proper does not begin until further down the canyon. The 

 bed-rock at the disputed place is the soft and decomposed gabbro of 

 Dutch Flat, which in places looks very much like clay. There are a great 

 many other considerations which favor the same result. The gravel areas 

 of both Plug Ugly and Jehoshaphat hills between Squires canyon and 

 Dutch Flat canyon have the distinct character of inclined benches above 

 the main channel, through which benches a supposed connection south- 

 ward could only have been effected by a deep and improbable gorge. 

 Dutch Flat and Indiana hill were evidently separated by a, low divide 

 corresponding to the present American-Yuba divide. When the deep 

 channel was filled up with gravel masses the stream began to deposit its 

 load on the adjoining broad inclined benches. Finally even the divide 

 was covered by the gravels, and a bifurcation might have taken place in 

 the latter part of the gravel period by means of which some of the waters 

 of the Yuba found their way over to the American watershed. 



If the Tertiary deposits and flows were removed from the region 

 between Dutch Flat and Badger hill an old longitudinal valley would be 

 exposed to view with a high ridge rising both on the eastern and the 

 western side. It cuts the strike of the probably ( arboniferous clay slates 

 and siliceous slates at a small angle. The lateral ridges are in part com- 

 posed of harder siliceous rocks, in pail of softer clay slates. The only out- 



'■■ Auriferous Gravels, p. it:'.. 

 tAurii'erous Gravels, p. 153. 



