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72 DISTRIBUTION OF GOLD IN GRAVEL.
Tuolumne River Claims. —
The gold alluvions found near and along the banks of the Tuolumne
River, Stanislaus County, present some striking examples of the
distribution of the precious metal. The pay dirt in the Chesnau claim
is confined to within six feet of the bedrock. In the Sicard claim,
six hundred feet south of the last and across a ravine, with banks
twenty to forty feet high, the gold is disseminated more generally so
long as there are no sand strata ; but whenever the latter appear the
pay is confined to near the bed-rock.
In
the Patricksville Light claim the pay stratum is six or seven feet
thick and adjoins the bed-rock. The gold is concentrated in this layer
so long as there are sand strata in the bank, but with their
disappearance it becomes more diffused throughout the detritus.
At the French Hill claim the pay was limited almost exclusively to the gravel near the bed-rock.
Nevada County.—The
bulk of the pay dirt in the cement gravel in Nevada County is within
thirty feet of the bottom. In drift claims the workings are nearly
always confined to within a few feet of the bed of the channel.
Sand generally poorer than Gravel.—In
the gold-bearing drift of the Sierra Nevada layers consisting
exclusively of wash-sand are generally found to contain very little if
any of the precious metal.
Rich Pay in Undulations and Depressions.—
At French Hill, Stanislaus County, where the bed-rock was undulating,
and in depressions found around a little hill formed by a sudden rise
in the bed-rock, the gravel paid better than in any other portion of
the claim.
The
gold-fields south of Miask,* in the Ural Mountains, present a similar
case, all the undulating ground and depressions around conical hills
being the most productive of gold.
At the Patricksville Light claim a large hole in the
* " Russia and the Ural Mountains," vol. i. p. 488.
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