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Placer Deposits

Placer deposits are knowm in only one locality. For
2,000 fect or more below the lower ond of the canyon on Bob
ereek, represonting a stretch starting not far above the mouth
of the creek, there are old placer diggings. No accurate
knowledge of the production is available, but it is probable
that it was not great nor highly remunerative. Diggings in
recent years have yielded very low returns. The deposits are
of interest because of their bearing on the source of the gold.
Very little black sand is found with the gold near the canyon,
but lower down where the overburden is clearly heavy there is
much. The black sand was undoubtedly derived from the drift.
Going up the stream toward the canyon the gold appears fresher
and rougher. Gold from near the canyon has attached to it
material that resembles the altered rock and vein material of
the nearby lode deposits as well as quartz. The ratio of gold
to silver, 717 to 255 and 732 to 257, of the placer gold is
fairly constant whether it is derived from near the canyon or
the sections where much drift has been washed. From the
foregoing data it would appear certain thet the gold came from
the altered rock in the canyon section. The amount of rock
eroded from the present canyon might be approximately 5,000,000
tons. It becomes apparent, therefore, that the yield of free
gold from the rock is probably relatively small.

The gold is in the main fine and mich might have been
carried away beyond the placer workings. Nuggets range up to
68 cents at $35 an ounce. -

Bob Creek now flows in a canyon for a distance of
about 1,500 feet. The upper end of the canyon is marked by a
contact with Tertiary lavas and the lower end by the mill on

this property. The canyon is new and cut out of the rotten