Clark Fork

Region West, Northwest
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Cluster of historical silver-lead-zinc-copper-antimony-gold deposits.
Identified resources Historical production of copper, gold, lead, silver, and zinc.
Production Most important producers of Pb-Ag ore in northern Idaho outside of the Coeur d'Alene district; production 1913 through 1943: 201,717 short tons of ore, 37.28 fine oz Au, 1,004,647 fine oz Ag, 20,242 lbs Cu, 24,247,852 lbs Pb, 774,300 lbs Zn (1942-43 only) (Anderson, 1947b).
Status Past mining.
Estimated resources Unknown.
Geologic maps Lewis and others (2020), scale 1:24,000; Harrison and Jobin (1965), scale 1:62,500.
Geophysical data Inadequate Rank 3 to 4 aeromagnetic and Rank 4 aeroradiometric coverage.
Favorable rocks and structures Wallace and Striped Peak Formations, members of the Precambrian Belt Supergroup; closely associated with faulting and igneous activity that is probably of early Tertiary age (Anderson, 1947b).
Deposits Lawrence mine (MRDS dep_id: 10105566), Hope mine (MRDS dep_id: 10088842), Whitedelf mine (MRDS dep_id: 10103876), Ralph prospect (MRDS dep_id: 10120083), Little Senator prospect (MRDS dep_id: 10069974).
Evidence from mineral occurrences MRDS.
Geochemical evidence Galena and sphalerite are ore minerals, with calcite, pyrite, sericite, and siderite.
Geophysical evidence Unknown.
Evidence from other sources Unknown.
Comments The lead-silver deposits are much like those in the Coeur d'Alene district, but on the whole they have a somewhat higher proportion of silver and antimony because of a late local hypogene enrichment. Fundamentally, however, they are galena siderite fillings and replacements along zones of fractured and fissured rock" (Anderson, 1947b).
Cover thickness and description Unknown.
Authors Jane M. Hammarstrom, Virginia S. Gillerman, Reed S. Lewis, Christopher A. Tate.
New data needs Digitization of geologic maps, geophysics.
Geologic mapping and modeling needs Needs digital geologic map coverage.
Geophysical survey and modeling needs High-resolution, Rank 1 aeromagnetic and aeroradiometric surveys, although not useful for this deposit type.
Digital elevation data needs Lidar in progress.