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THE GRAVEL: EL DORADO COUNTY. 101 
adding much to the expense of working the claim. One of these blocks was found, on measure- 
ment, to be fifty-five feet in length, and to be equal in dimensions to a cube of thirty feet, and was 
estimated to weigh 2,000 tons. 
At the Henderson Claim, on the north side of Negro Hill, a little northeast of the Oldfield, there 
have been two or three acres washed off, the maximum height of the bank being 115 to 120 feet. 
The amount of metamorphic gravel here is very small, and it forms a stratum of a few feet in 
thickness upon the bed-rock. The great mass of the bank consists of beds of volcanic sands and 
gravels. These are beautifully stratified in horizontal layers, and much of the material is very 
thinly and delicately bedded. This ground is said to be very rich in gold. 
The maximum depth of the gravel, including the “ mountain gravel,” at Indian Hill, is about 
sixty or seventy feet ; and there are five or six acres over which the average depth is twenty feet. 
On the top is a thin capping of “ black lava,” perhaps from three to four feet in thickness, — not 
enough to give any serious trouble in hydraulicking. 
At the southwest end of Clay Hill, a little southwest of Indian Hill, there has been a quarter of 
an acre of ground washed off, exposing a bank twenty-five to thirty feet high, of which the lower five 
or six feet consist of quartz and metamorphic gravel, generally rather fine : all the upper portion 
is a coarse “mountain gravel,” occasionally containing very large and very smoothly rounded 
boulders ; one of them was found to be not less than ten feet in diameter and nearly spherical in 
shape. 
At the west end of Indian Hill, a little to the northeast of Clay Hill, a considerable extent of 
ground has been worked, showing the face of a bank from twenty to thirty feet high, for a couple 
of hundred feet in length. Only a thin layer on the bed-rock here could have been of metamorphic 
material, for the whole face now visible is volcanic. The lower portion consists, to a great extent, 
of gray voleanic sand, with occasional thin layers of fine “ mountain gravel.” The upper portion 
of the bank consists entirely of coarser mountain gravel ; and the structure of the bank shows, that 
after the sand had been deposited, it was again here and there channelled out to a greater or less 
extent, before the mountain gravel was laid in heavier masses over it. 
At the Sugar Loaf, a hill on the south side of Webber Creek and about a mile below Diamond 
Springs, an area about 800 feet long and 200 wide was first drifted out, and has since then been 
washed off, so as to have removed the whole original top of the hill. The gravel which averaged 
about fifty feet in thickness, and was not capped at all with voleauic materials, was metamorphic, 
well-washed, and contained a good many quartz pebbles, but no large boulders, stones of more 
than a hundred pounds’ weight being rare. Most of the pebbles which were not of quartz were 
thoroughly decomposed, and the mass of tailings slacks quickly on exposure to the air. The total 
yield of this deposit was, it is said, not far from $ 3,000,000. 
On the east side of Bean Hill, just northeast of the Sugar Loaf, at Diamond Springs, the bank 
exposed is about 1,200 feet long, and ranges from twenty to forty feet in height. About four or 
five acres of ground have been washed off here, with an average depth of about twenty feet. The 
gravel is mainly metamorphic, yet containing a good many boulders of “ white lava” and occasion- 
ally of other volcanic materials. Nearly all the pebbles, except those of quartz, are much decom- 
posed, so that the bank washes very easily. 
In the Deadhead Claim, three quarters of a mile below Newtown, on the south side of Webber 
Creek, an area has been washed off estimated at about 800 feet long by 200 feet wide, with an 
average depth of 30 feet. The gravel here is chiefly metamorphic, but contains a good many volcanic 
boulders, a large proportion of which are “white lava,” scattered throughout its mass, and also 
many boulders of a rock of granitoid texture, but consisting of quartz and feldspar without any ap- 
preciable quantity of mica. 
At Brownsville, on the North Cedar Creek, the gravel in the front of the claims is said to have 
been seventy feet thick, at least, above the bottom of the workings, the bed-rock not being reached. 
The gravel grew thinner as they went into the bill, its upper surface-sloping to the south. It was 
almost exclusively a quartz gravel, the pebbles being rarely very large. 
