194 THE AURIFEROUS GRAVELS OF THE SIERRA NEVADA. 
ness of the Smartsville Consolidated Company’s gold may be taken at .927, and its general mode 
of occurrence is in fine particles ; there are no nuggets. Mr. Redfield stated that the gold of the 
highest percentage near Timbuctoo came from the upper gravel, —the ‘ red gravel,” as it is called 
in that particular locality. The gold from the channel nearest the bed-rock is more in amount, but 
hasa larger admixture of silver. In the Michigan ground — in the upper end, at least — the richest 
dirt was near the top of the bank, according to Mr. McAllis, while there was nothing but a rather 
fine sand on the white cement. Farther down, toward Timbuctoo, the richest stratum lay on the 
white cement. The best ground of the Smarisville Consolidated is in a red streak. In the Smarts- 
ville region, throughout, the coarse gravel or cement is generally rich and the fine poor. It seems 
as if the gold came when the stream had power enough to bring a coarse material and boulders of 
considerable size ; but when the fine gravel and sand were deposited, the gold was left higher up 
the stream. 
The richest spots in the present channel of the Yuba, in the neighborhood of Smartsville, — 
namely, Rose’s Bar, Barton’s Bar, and Park’s Bar— Barton’s Bar being not quite so rich as the 
other two, — seem to owe their productiveness to the erosion of portions of the old river channel. 
In the region bordering the Yuba on both sides of that stream, and be- 
tween Timbuctoo and Marysville, there are extensive areas covered with 
shallow detrital deposits, with more or less volcanic material resting on them. 
A similar condition of things has already been mentioned as occurring at 
various points in the Sierra along the edge of the foot-hills, as, for instance, in 
the vicinity of the Merced River. These shallow gravel beds do not usually 
appear to contain gold enough to be worth working ; and those below Smarts- 
ville and Timbuctoo are, so far as known to the writer, of no value. The 
area which they cover is designated on the map, and no further information 
can be given at present in regard to them. 
There being such an extensive area near Smartsville, and one so deeply 
covered with highly auriferous gravel, it would naturally be expected that 
this channel could be followed almost continuously upward, so that its con- 
nection with the immense gravel deposits higher up in the Sierra along the 
Yuba could be easily made out. This, however, appears not to be the case. 
From Smartsville upward there is a distance of eight miles, in a line due 
east, to the west end of the Rough and Ready gravel, without any interven- 
ing deep gravel deposits, unless it be a very small area just south of Deer 
Creek, opposite the Anthony House. This would seem to cut off all idea of 
a connection, on the south side of that stream, between the Smartsville and 
Grass Valley channels, the shallow placer deposits found for two or three miles 
below Rough and Ready not being of importance enough to be more than 
mentioned in this connection. 
On the north side of Deer Creek, however, there are quite a number of 
detached elevations capped with lava and accompanied by gravel beds, oc- 
