

62 [APPENDIX 



of about four miles, with, an elevation of four thousand feet above the 

 sea for the greatest part of its length.' 



From the examinations that were made upon this range, there are 

 abundant evidences that an ancient stream,, flowed through this section, 

 of the country, and in a direction parallel with its then existing moun 

 tain ridges, and the extensive mining operations conducted in/the south 

 east part of Sierra county 011 this range, has been the means of demon 

 strating this fact, which -had heretofore been strongly suspected only. 

 The outliers of its banks are very definitely marked throughout the 

 entire length of the formation under consideration, and its former bed 

 filled in many places, with a volcanic sand and ashes, which probably 

 accompanied its displacement. 



Iir the county Sierra these peculiarities ar-e best observed ; in the" 

 viqinity, and foy ten miles west of Downieville, the hills are covered 

 with a volcanic brecia and tufa, which may be conveniently studied be 

 tween the Negro Tent and Galloway's Banch, also on 'all the hills and 

 ravines surrounding Yumanna on Oregoia Creek. On the creek the 

 tufaceous deposit is found to the depth of sixty feet. L 



The exact point from which these immense quantities of volcanic 

 materials were ejected, is somewhat obscure ; yet there are reasons for 

 the supposition that they had their origin in the truncated cones which 

 lie a few miles to the north-east, and of which the Pilot Peak forms one 

 of the principal points or centres of this rugged and forbidding district. 

 This presumption is based on the grounds that between Uilot Peak and 

 Yumana there are ample evidences of a direct connection with these 

 larger centres of disturbance ; an extensive dike of black scoriaceous 

 and vesicular, lava is traceable throughout the entire distance between 

 Yumana and the Pilot Peak, passing through the hill north-west of 

 Downieville, and within two hundred yards of the town, it crosses the 

 river at this point and appears at Durgan's Flat on the opposite side of 

 the stream, from thence it is again met near Galloway's Ranch, and con 

 tinues from there t9 the high bluff which overhangs the town of 

 Yumana, on Oregon Creek. There are no other true volcanic cones in 

 this section that would seem commensurate with so large a scale of oper 

 ations, except those above noted, though the minor peaks undoubtedly 

 added much to the general result. 



The displacement of this ancient stream and the subsequent filling of 

 its bed has opened a new and rich field for scientific research. in this 

 State, but its more direct and economical bearings are that it affords an 

 equally new and extensive field for the operations of the placer miner, 

 and that thus far has proved itself equal to that of any range yet discov 

 ered in this country. Besides being equally abundant in its produce of 

 gold as far as opened, with the best placers of the State, it possesses the 

 advantage of being the most extensive of any one system which has yet 

 been found. The peculiarities which characterize this formation and 

 which distinguishes it from all others in the State, are the following : 

 the boulders found throughout its entire extent are very uniform -in their 

 characters, and are composed of quartz exclusively, (or nearly so) this 

 has a bluish- watery color in the mass, highly trans lucent and vitreous 

 when fractured, constituting ninety-seven per cent, of all the stones found 

 in^lie deeper diggings, they are invested by a dull but deep blue earthy 



