THE CHANNELS: IN PLACER AND EL DORADO COUNTIES. 



107 



to pitch, to the south. This is the only indication yet discovered of a northwestern rim to the 



great Forest Hill channel, and this is over a mile distant from the known position of the south- 

 eastern rim. 



Something over a mile northeast of Bath, the mining operations have shown that the bed-rock 

 rises quite high in the immediate vicinity of a deep channel. In the bottom of Volcano Canon, 

 at the crossing of the upper road from Forest Hill to Michigan Bluff, a shaft was sunk 153 feet 

 deep through volcanic cement. Before reaching the bed-rock, and on the crest of the ridge, a 

 quarter of a mile west of this, the bed-rock rises to an elevation of about 400 feet above 1 the mouth 

 of the shaft. At the bottom of this shaft the bed-rock was found pitching to the northwest, show- 

 ing that they were on the southeast side of the lowest part of the channel. They then followed 

 down some ten or twelve feet lower on the rock, and found the gravel very hard, but rich in gold. 

 About half-way between here and Bath, and on the northwest side of Volcano Canon, is the Maine 

 Boys' Tunnel, which was driven through very hard bed-rock, in a direction nearly north (magnetic) 

 some 500 or 600 feet, and at its end broke through into what is believed to be the same channel 

 as that reached by the shaft above described. They then went down with a slope on the surface 

 of the bed-rock to a vertical depth of ninety feet below the tunnel before reaching the bottom of 

 the channel, when the water drove them out. 



Near the northwest end of the tunnel in the Paragon Mine, at Bath, the pay streak and all the 

 accompanying strata, so far as here prospected, above and below it are cut sharply off by a mass of 

 volcanic cement precisely similar in character to the so-called " gray cement " of the Deadwood 

 Mines, which contains much partially carbonized wood and some metamorphic pebbles. On strik- 

 ing this mass the tunnel was continued for about a hundred feet into it to the northwest, in the 

 hope of passing through it and finding gravel again beyond it ; but without success. The surface 

 of demarcation between it and the elided gravel strata was however followed by drifts for a dis- 

 tance of nearly GOO feet, and was found, though somewhat crooked, to have a general direction of 

 very nearly cast and west (true course) and a pitch or dip of about 45° to the north. There can 

 be little doubt that this body of cement marks the position of a stream which, subsequent to the 

 deposition of the gravid strata in the Paragon Mine, eroded a considerable portion of them, and 

 then afterwards had its own channel filled with volcanic mud. And it is not at all improbable 

 that it may have been the same stream whose channel was struck in the Maine Boys' Tunnel and 

 in the shaft in Volcano Canon. If this be true, the general course of the stream was southwesterly, 

 and it came from somewhere in the Michigan Bin If divide. 



The channel at Jones's Hill, four miles northwest of Georgetown, appears to run very nearly west 

 (magnetic) in the Columbia Mine, with a grade falling in that direction, heavy enough to make 

 brakes necessary on the cars. The channel passes under the southern slope of the hill, and is said 

 to range from fifty or sixty feet in width to over two hundred, averaging perhaps a hundred. It 

 is described as well-defined, with a high and steep rim-rock rising on the north side, while the 

 southern rim is not more than ten or twelve feet high. The channel has been followed and worked 

 here, by drifting, for over a quarter of a mile ; it has generally paid well, and in spots lias been 

 very rich. 



In the Boanoke Tunnel, near Bottle Hill, the channel varied from ten to a hundred feet or more 

 in width. The whole length of the tunnel through the hill was rather more than a mile, and it 

 was somewhat crooked, although its general course was N. 50° W. (magnetic). The channel is 

 narrow, and the rim-rock high on both sides, although it is not known how high. It is said, how- 

 ever, that an incline was once run up on the northeast rim to a height of fifty or sixty feet above 

 the tunnel, and that here an upper stratum of gravel was struck, which was about four feet in 

 thickness, the bed-rock then remaining nearly level in a northeast direction, so far as it was fol- 

 lowed, or for a distance of fifteen or twenty feet, indicating that the top of the rim had been 

 readied. 



At a point where the channel in Boanoke Hill leaves the hill, a little side channel comes in from 

 the south. This little channel, where seen by Mr. Goodyear, was not more than twelve or fifteen 





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