Summary of Heavy Metals Studies At San Juan Ridge, Nevada County, California.
NTIS: PB/226-694 Available for Reference At Bureau Libraries :87 pages
The Tertiary channel gravel deposits in northern California were selected for detailed investigation by the federal Bureau of Mines as part of a national program to locate potential sources of gold that might be developed rapidly by large-scale mining operations. This report summarizes the individual investigations by five Bureau research centers representing mining and metallurgy subsystems for possible solutions to the problem areas that long have discouraged resumption of large-scale mining in the deposits, and gives conclusions and recommendations after 2 years of field work at the deposits on San Juan Ridge. The studies indicate that modern mining technology can cope with the environmental problems that closed the immense hydraulic mines in 1884. However, they also indicate that mining can be conducted with only marginal profits unless the price of gold remains substantially above $70 per ounce or unless sufficient byproducts can be recovered and sold to place the average value per cubic yard of gravel into a positive commercial range.
NTIS Accession No.
NTIS: PB/226-694; Available for Reference At Bureau Libraries