PLACER MINES—SILICIFIED WOOD—-CAÑONS. 263 
and carried out through the tunnel upon a tram-road, and dumped into a large bin made to 
receive it. The refuse, or attle of the Cornishman, is switched off from the main track and 
dumped in another place. The ‘‘ pay-dirt,’’ as the auriferous earth is called, is occasionally 
moistened with water while in the bin, and when a quantity is collected, it is washed out in a 
long sluice. "This pay-dirt consisted, in great part, of fine talcose clay, derived from the abra- 
sion of talcose slate, and was mingled with fragments of the slate broken from the bed-rock. 
On sprinkling the surface of the heap with water, the gold became visible in yellow fragments 
and flattened, bean-shaped masses. The gold is very coarse, and is not much worn and rounded 
by attrition. Many of the masses are crystalline, and are distorted and flattened octahedrons, 
evidently not transported far from their original source. Quartz crystals are also found in this 
earth, and, although the sharp points and angles are removed by abrasion, the faces retain their 
natural polish, and show that the agitation of the drift or gravel, with which the crystals were 
deposited, was not of long continuance. Many large masses of cellular quartz, from three to 
six and ten inches in diameter, are also thrown out from the mine, and there being no provision 
for erushing them, they are thrown aside. On crushing one of these in a mortar, and washing 
the powder, a string of «^ color”? was obtained. It is evident that these masses were not trans- 
ported far from their source, and there is a quartz vein in the vicinity withgnt doubt. 
At Sarahville, several miles beyond, the auriferous drift was exposed in bluffs, which, at one 
point, presented the following succession of beds from the surface downwards : 
Feet. 
Blue clay 10 
Clay with oxide of iron 9 
White clay 9 
Sand and clay $ 
Sand 9 
Gravel and boulders 95 
Sand and gra vel 4 
Coarse gravel and boulders 95 
The point of junction the drift with the slates was not visible, but the lower stratum of 
gravel and boulders probably rests upon the edges. Many of the rocks thrown out from these 
layers of drift are of volcanic origin. One block, over a foot in diameter, was dark-green, and 
broke, with a conchoidal fracture, into sharp, vitreous fragments like pitchstone. It is mottled 
with red and green veins, and is chiefly silex. Many of the masses of slate are very hard and 
highly metamorphosed. 
Masses of silicified wood and even large trees turned into stone have been found in this vicinity 
In one claim it is said that a silicified tree was eighty feet long. A fragment of it, which was 
Shown to me, was nearly white, but compact and glassy, every cell and pore being filled with 
the silica. The grain, rings of annual growth, and medullary rays were remarkably distinct. 
Several specimens of other masses were procured. A slab of rock or quartz was carefully pre- 
served by one of the residents here as a great curiosity, it being covered on one side by the moss 
like and arborescent coats of oxide of manganese. These are generally mistaken for fossil plants. 
It is said that about two years ago some miners turned up a slab of this kind, very distinctly 
marked, and, seeing a resemblance in the outlines to the pine-covered hills, they concluded it to 
be a natural daguerreotype ofthe ridges on the opposite side of the river. 
The road from Forest Hill to Michigan City winds about on the elevated plateau of the divide, 
among tall pines and firs, and skirts the deep cañoned valley of the Middle Fork. The stream 
was flowing nearly three thousand feet below us for most of the distance. These cañons are 
