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188 



THE AUKIEEROUS GEAVELS OF THE SIEREA NEVADA. 



of the south rim of the channel, — the Kansas shaft being pretty nearly in the centre. It would 

 require only a slight additional curving to the south from this point to bring us into the known 

 line of the channel at the Live Oak shaft. All attempts to trace in detail the course of the 

 channel to the west of the Manzanita Diggings were unsatisfactory, on account of the accu- 

 mulation of boulders and other material on any bed-rock that may have been exposed at any 



previous time. 



What I have thus far given is substantially all the information I obtained concerning the prob- 

 able course of the old channel. In regard to its width the statements are, as might be expected, 

 anything but precise* At the Kansas shaft the width of channel was given at about 200 feet. 

 At the Manzanita Diggings Mr. Maltman said the main channel seems to find its deepest bed-rock 

 in a narrow gorge of, say, thirty feet in width, Near the building in the diggings (previously 

 referred to) I was told that the width of the channel was about ninety feet, while farther to the 

 east and north it spread out in such a way that there is a width of six or eight hundred feet which 



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and where the height of bank is 



it will pay to wash. From such data it is clear that we can get only a rude approximation to tin 



reality. 



The total thickness of the river deposit in this neighborhood is considerable, but there is a large 



percentage of clay and much that contains little or no gold. The top of the Kansas Shaft is about 

 fifty feet (vertically) below the lower line of the lava on the Washington Eidge, and is sunk for 

 the whole distance of 220 or 228 feet through alternating strata of pipe-clay and poor gravel ; the 

 layer of pay gravel on the bed-rock being not much if any over fifteen inches in thickness. At the 

 Manzanita Diggings the thickness of the blue gravel (substantially, according to Mr. Maltman's 

 statement) varies from a few inches up to nearly or quite twenty-five feet in the bed of the chan- 

 lie l ? — the variation arising mostly from the irregularities of the bed-rock. Above the blue gravel 

 comes pipe-clay for a considerable thickness, say, in round numbers, twenty feet, and above this is 

 a newer gravel channel made up mostly of a mass of whitish gray pebbles. The thickness of this 

 bed may be taken at twenty feet. Above this comes still another deposit of less pure clay reaching 

 to within a few inches of the grass roots. This would be an. approximate description of the eastern 

 end of the bank — where the principal washing was going on 

 not far from a hundred feet. At another part of the bank I observed the section and estimated 

 the thickness of the different strata something as follows : Above the top of the face of the bank 

 was a considerable thickness of gravel and clay reaching up to the lower line of the Sugar Loaf 

 lava, amounting perhaps in all to fifty feet. The first stratum exposed at the top of the bank was 

 about four feet of gravel. Below this was a stratum of pipe-clay sixteen feet in thickness, followed 

 by five or six feet of gravel. For the next fifty feet the material was mostly clay, with only occa- 

 sional lenticular masses of gravel. Whether there was any gravel below this or not could not be 

 seen, on account of the accumulations which had slidden down from the top. Mr. Maltman 

 claims a total height of bank of 170 feet. The face I observed was about 300 feet in length. Be- 

 yond those limits, in either direction, the section would have varied in more or less particulars. 

 The outlet of the Manzanita Diggings is nearly on the line of the old Coyote Diggings (to which 

 reference will again be made). The next hill to the west — distant about a quarter of a mile, and 

 lying to the east of the present road to Blue Tent — was known as Pontiac Hill, and next to this, 

 on the west of the present road, came Buckeye Hill. Next west of Buckeye Hill came Oregon 

 Hill. These hills have all been washed away, and no means were available for finding out what 

 the peculiarities of their gravel were, if any, excepting that Oregon Hill was said to be the last 

 which carried any " fine quartz gravel." Next west of Oregon Hill is American Hill, where there 

 is still considerable coarse gravel left to work over ; but the prevailing impression is that it will not 

 quite pay. Between American Hill and the Sugar Loaf a large mass of gravel has been removed 

 so as to expose considerable bed-rock. At and near where the Newtown road (or one of them) 

 crosses these old workings the bed-rock slopes gently to the south. The house and part of the 

 vineyard of Mr. Rogers stand directly on the American Hill gravel. On three sides of his house 

 the perpendicular bank is only a few rods off, while to the south the slope to Deer Creek is more 



