Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Geophysical Measurements of Gold-Bearing Gravels, Nevada County, CA.

Authors
Tibbetts-BL; Scott-JH
Source
NTIS: PB 210 193 :32 pages
Link
NIOSHTIC No.
10008823
Abstract
Comprehensive geophysical measurements were made in the Tertiary channel gravel deposits of Badger Hill, California, with the refraction seismograph, gravimeter, and well logging equipment, to develop a three-dimensional physical model of the gold-bearing gravels. Tests were also made of the applicability of magnetometer and electrical resistivity techniques. Results of 14 seismic profiles revealed four distinct layers with velocities of 1,600 ft/sec for loose gravel, 5,900 ft/sec for compact gravel, 8,600 ft/sec for cemented, blue gravel, and 15,500 ft/sec for bedrock. The depth to bedrock along the middle of the channel varied from a minimum of 100 feet in the hydraulically mined pit area to a maximum of about 300 feet in the upper bench area immediately south of the pit. These geophysical methods revealed that 40 percent of the drill holes necessary to delineate the deposit could be eliminated, at a cost saving of at least 30 percent.
Publication Date
19720101
Document Type
IH; Report of Investigation;
Fiscal Year
1972
NTIS Accession No.
PB-210193
NTIS Price
A04
Identifying No.
RI 7584
NIOSH Division
DRC;
Source Name
NTIS: PB 210 193
State
CA; NV;
TOP