Pioche Deposits

Past Producer in Lincoln county in Nevada, United States with commodities Lead, Silver, Gold, Manganese, Iron, Copper, Zinc, Arsenic

Sections on this page

Identification information
Geographic coordinates
Site location context
Geographic areas
Public Land Survey System information
Commodities
Materials information
Alteration
Mineral occurrence model information
Host and associated rocks
Nearby scientific data
Geologic structures
Ore body information
Controls for ore emplacement
Economic information about the deposit and operations
Mining district
Land status
Ownership information
Bibliographic references
General comments
Reporter information

Geologic information

Identification information

Deposit ID	10310394
MRDS ID	W002906
Record type	District
Current site name	Pioche Deposits
Alternate or previous names	Caselton (Combined Metals Reduction Co.) Mine, Ely Valley Mine, Prince-Virginia Louise-Davidson Mine, Raymond and Ely Mine
Related records	60001661

Comments on the site identification

This is a new record that includes all material in earlier MRDS record W002906, other earlier MRDS records for theindividual deposits, as well as additional new information.

Geographic coordinates

Geographic coordinates:	-114.45195, 37.93524 (WGS84)
Elevation	2130
Relative position	The Pioche District mines are located in the Pioche Hills southwest of Pioche, about 19 miles west of the Utah-Nevada border.

Site location context

Political divisions (FIPS codes)

Lincoln(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Pioche(quadrangle 1:24,000 scale)

Caliente(quadrangle 1:100,000 scale)

Caliente(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Meadow Valley Wash(hydrologic unit)

Lower Colorado-Lake Mead(hydrologic accounting unit)

Lower Colorado-Lake Mead(hydrologic subregion)

Lower Colorado(hydrologic region)

Geographic areas

Country	State	County
United States	Nevada	Lincoln

Public Land Survey System information

Meridian	Township	Range	Section	Fraction	State
Mount Diablo	01N	67E	14 17 22 23 26 32 33 04		Nevada

Comments on the location information

The Pioche District mines are scattered over a few square miles in the Pioche Hills (including Treasure Hill) west, southwest, and south of Pioche.

Commodities

Commodity	Importance
Lead	Primary
Silver	Primary
Gold	Primary
Manganese Critical	Primary
Iron	Secondary
Copper	Secondary
Zinc Critical	Secondary
Arsenic Critical	Tertiary

Comments on the commodity information

Ore Materials: argentite, cerargyrite, cerussite, galena, pyrite, sphalerite, chalcopyrite, gold
Gangue Materials: quartz, calcite, siderite, jarosite, limonite

Materials information

Materials	Type of material
Argentite	Ore
Cerargyrite	Ore
Cerussite	Ore
Galena	Ore
Pyrite	Ore
Sphalerite	Ore
Chalcopyrite	Ore
Gold	Ore
Quartz	Gangue
Calcite	Gangue
Siderite	Gangue
Jarosite	Gangue
Limonite	Gangue

Alteration

(Local) oxidation; hydrothermal

Mineral occurrence model information

Model code	72
USGS model code	19a
Deposit model name	Polymetallic replacement
Mark3 model number	47

Host and associated rocks

Host or associated

Host

Rock type

Metamorphic Rock > Metasedimentary Rock > Quartzite

Rock unit name

Prospect Mountain Quartzite

Stratigraphic age (youngest)	Early Cambrian
Stratigraphic age (oldest)	Neoproterozoic

Host or associated

Host

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

Combined Metals Member of the Pioche Shale

Stratigraphic age (youngest)	Early Cambrian

Host or associated

Host

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

Lyndon Limestone

Stratigraphic age (youngest)	Middle Cambrian

Host or associated

Host

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

Mendha Limestone

Stratigraphic age (youngest)	Early Ordovician
Stratigraphic age (oldest)	Late Cambrian

Host or associated

Host

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

Highland Peak Limestone

Stratigraphic age (youngest)	Middle Cambrian

Host or associated Host

Rock type Plutonic Rock > Granitoid > Granite

Rock type qualifier porphyry dikes

Stratigraphic age (youngest) Tertiary
Host or associated Host

Rock type Plutonic Rock > Porphyry

Rock type qualifier granite dikes

Stratigraphic age (youngest) Tertiary

Host or associated

Associated

Rock type

Sedimentary Rock > Clastic Sedimentary Rock > Shale

Rock unit name

Chisholm Shale

Stratigraphic age (youngest)	Middle Cambrian

Host or associated

Associated

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

Yellow Hill Limestone

Stratigraphic age (youngest)	Early Ordovician

Host or associated

Associated

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

Tank Hill Limestone

Stratigraphic age (youngest)	Early Ordovician

Host or associated

Associated

Rock type

Metamorphic Rock > Metasedimentary Rock > Quartzite

Rock unit name

Eureka Quartzite

Stratigraphic age (youngest)	Late Ordovician
Stratigraphic age (oldest)	Middle Ordovician

Host or associated

Associated

Rock type

Sedimentary Rock > Carbonate > Dolomite

Rock unit name

Ely Springs Dolomite

Stratigraphic age (youngest)	Late Ordovician

Host or associated

Associated

Rock type

Sedimentary Rock > Carbonate > Dolomite

Rock unit name

Silverhorn Dolomite

Stratigraphic age (youngest)	Middle Devonian

Host or associated

Associated

Rock type

Sedimentary Rock > Carbonate > Dolomite

Rock unit name

West Range Dolomite

Stratigraphic age (youngest)	Late Devonian

Host or associated Associated

Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Dacite
Host or associated Associated

Rock type Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite

Host or associated	Associated
Rock type	Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Dacite

Host or associated	Associated
Rock type	Volcanic Rock (Aphanitic) > Intermediate Volcanic Rock > Andesite

Host or associated

Associated

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

Bristol Pass Limestone

Stratigraphic age (youngest)	Early Mississippian

Host or associated Associated

Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite

Host or associated	Associated
Rock type	Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Rhyolite

Host or associated

Associated

Rock type

Sedimentary Rock > Clastic Sedimentary Rock > Siltstone

Rock unit name

Peers Spring Fm

Stratigraphic age (youngest)	Late Mississippian

Host or associated

Associated

Rock type

Metamorphic Rock > Metasedimentary Rock > Quartzite

Rock unit name

Scotty Wash Quartzite

Stratigraphic age (youngest)	Late Mississippian

Host or associated Associated

Rock type Plutonic Rock > Granitoid > Quartz Monzonite

Rock type qualifier intrusives

Host or associated	Associated
Rock type	Plutonic Rock > Granitoid > Quartz Monzonite
Rock type qualifier	intrusives

Host or associated

Associated

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

Bailey Spring Limestone

Stratigraphic age (youngest)	Pennsylvanian
Stratigraphic age (oldest)	Mississippian

Host or associated Associated

Rock type Volcanic Rock (Aphanitic) > Pyroclastic Rock > Tuff

Rock type qualifier sedimentary

Host or associated	Associated
Rock type	Volcanic Rock (Aphanitic) > Pyroclastic Rock > Tuff
Rock type qualifier	sedimentary

Nearby scientific data

(1)	-114.45195, 37.93524	ListMap

Economic information

Geologic structures

Type of structure	Regional
Structure description	E-W and N-S normal faulting before thrusting; N60 degree S faults mineralized; N-S, NW-trending post mineral. The Pioche Hills appear to be a window in a regional thrust of upper Cambrian rocks over lower Cambrian and Tertiary volcanics. Pioche Shale bed dropped by closely spaced parallel normal faults mineralization principally in Combined Metals bed of the Pioche Shale. Highland Peak overthrust
Type of structure	Local
Structure description	steeply dipping fissures: N50-70E mineralized zone

Ore body information

General form tabular to lenticular orebodies, tapering away from fissures

Controls for ore emplacement

Ore occurs in tabular replacement bodies, at the intersection of steep fissures and limestone beds in Pioche Shale.

Comments on the geologic information

The Combined Metals Member of the Pioche Shale is the host rock for the replacement orebodies. It consists of 3 parts: (1) a lower 3 ft of massive limestone (2) a middle 3-ft thick calcareous sandstone (which in the orebody is unreplaced) and (3) an upper 30-ft layer of thin-bedded nodular limestones, usually only 2-3 inches thick and so nodular that they look like "beds of flattened potatoes". The nodules are coated with a thin black carbonaceous skin. The Pioche Shale belt trends NW between 2 faults.

Economic information about the deposit and operations

Operation type	Underground
Development status	Past Producer
Commodity type	Metallic
Deposit size	Large
Significant	Yes
Discovery year	1863
Discoverer	Hamblin (Panaca)
Year of first production	1869

Mining district

District name	Pioche District

Land status

Ownership category	Private
Ownership category	BLM Administrative Area
Area name	Las Vegas BLM administrative district

Ownership information

Type Owner-Operator

Owner Kerr-McGee

Comments on the workings information

The veins were developed by extensive underground workings; shafts, adits, trenches, cuts, and prospect pits. Most of the old underground workings were caved by the 1980s. There was a small open pit and heap-leach operation working in the 1980s.
Water was in the old workings at the 1200 foot level.

Comments on other economic factors

From 1905 to 1958 the total production from the Pioche district mines was 810,366 ounces of gold, 17,956,492 ounces of silver, 6,254,900 pounds of copper, 317,007,800 pounds of lead, 640,224,100 pounds of zinc, and 711,400 tons of manganese ore. 1869 to 1904 production was not broken down.

Reserves: 1958: Caselton type ore: 2,642,830 metric t (includes production) 0.046 opt Au, 5.32 opt Ag, 4.81% Pb, 11.82% Zn; Pan American type ore: 149,629 metric t, 0.028 opt Au, 1.64 opt Ag, 1.39% Pb, 2.66%Zn, 9.7% Mn
1952: Caselton type ore: 674,300 metric t (includes production) 0.013 opt Au, 0.65 opt Ag, 0.6% Pb, 9.5% Zn, 0.4% Cu
1949: Caselton type ore: 197,921 metric t (includes production) 0.035 opt Au, 3.21 opt Ag, 1.24% Pb, 9.7% Zn, 0.14% Cu; 12.32% Mn (oxidized ore); 31.5% Fe (oxidized ore)

Comments on development

The initial mineral discovery in Pioche occurred in 1863 and mining production began in 1869. The original ore consisted of oxidized silver chlorides occurring in fissures in Cambrian quartzites. The Raymond and Ely vein system contained high-grade lead-silver ore that was mined in the 1870s
At one time Pioche was one of largest silver districts in the United States. Total mineral production exceeded $130,000,000. The primary metal values were for gold, silver, lead, zinc and copper. Low-grade argentiferous manganese oxides were also found in the region. Major periods of production were: 1895-1901; 1912-1920; 1934-1953; and 1958-1959. Minimal activity has occurred from 1959 to the present time. Early milling occurred in Pioche, but a shortage of water forced the mills to be relocated to Bullionville (near Panaca) around 1871. In 1924 Combined Metals Reduction Company developed a selective flotation process to treat the massive lead-zinc sulfide ores. Combined Metals Reduction Company processed ore at a mill in Bauer, Utah from 1923-1941, until the Caselton Mill was built in 1941. Mountain Mines, Inc. acquired the Caselton Tailings after the bankruptcy of Combined Metals Reduction Company in 1976. Mountain Mines, Inc. claims to have produced precious metals from the tailings with a small chemical processing facility located in the vicinity of the tailings.
Numerous mining companies have had operators or exploration activity at site, including: Meadow Valley Mining Company (1864-1876); Consolidated Mining Company (1880's); White Pine Minerals Company (?); Combined Metals Reduction Company (1924-present); Pioche Manganese Company (WWII); Comet Coalition Mining Company (1964-1978); St. Patrick Mining Company (1975); Bunker Hill Mining Company (1976-77); Kerr-McGee Chemical Company (1980); Mountain Mines, Inc. (1976-present). Homestake Mining Company, Prince Consolidated Mining Company and Anaconda Company also have been active in the area.
Midway Gold Company has recently (2004) been exploring for a faulted offset of the high-grade silver-gold Salt Lake Pioche vein under post- mineral volcanic rock. The property consists of five patented and 36 unpatented claims lying south of the town of Pioche on a combination of private patented mining claims and BLM administered lands. Midway began a 3500 foot reverse circulation drill program on the Pioche Project in October 2004.

Reference information

Bibliographic references

Deposit

Westgate, L G. and Knopf, A., 1932, Geology and Ore Deposits of the Pioche District, Nevada: USGS Prof. Paper 171, 79p.
Deposit

Koschmann, A. H. and Bergendahl, M H, 1968: Principal Gold Producing Districts of The United States: USGS Prof. Paper 610
Deposit

Pack, F. J., 1906, Geology of Pioche, Nev., and Vicinity: Nev. School of Mines Quart. Vol. 27 Nos. 3 and 4, pp. 281-333
Deposit

Anderson, J. C., 1922, Ore Deposits of Pioche Dist: Eng & Min Jour, Vol. 113, p. 279-85.
Deposit

Hill, J M, 1916, Notes on some Mining Districts in E. Nev.: USGS Bull. 648, p. 124-137.
Deposit

Tschanz, C. M. and Pampeyan, E. E., 1970, Geology and Mineral Deposits of Lincoln Co., Nev,: Nev. Bur. of Mines Bull. 73 p. 125-129.
Deposit

Lincoln, F. C., 1923, Mining Districts and Mineral Resources of Nevada: Reno, Nevada Newsletter Pub. Co., p. 125-129
Deposit

James, L.P., and Knight, L.H., 1979, Stratabound lead-zinc-silver ores of the Pioche District, Nevada - Unusual "Mississippi Valley" Deposits; in RMAG-UGA 1979 Basin and Range Symposium proceedings.
Deposit

NBMG MI-80
Deposit

Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette.
Deposit

State of Nevada Interagency Abandoned Mine Land Environmental Task Force (IAMLET), 1999, report, http://www.nv.blm.gov/AML/IAMLETreport.htm.

General comments

Subject category

Comment text

Deposit

The main orebody at the Caselton, Raymond & Ely/Combined Metals Reduction #1 mines is the result of selected replacement of the Combined Metals Limestone bed where it intersects the steeply-dipping Greenwood Fissure, which is a fault of slight displacement, usually expressed as a thin gouge seam but which may be up to 5 feet thick. It trends N70E, and dips 65-70N, nearly paralleling the Raymond and Ely vein, which dips 75S. The ore has been offset by many cross-faults the main orebody is a tabular massive sulfide bed extending laterally into the limestone layer, thickest (30-40 feet) adjacent to the Greenwood Fissure, and tapering down away from it. Bedded ore occurs up to 200 feet on either side of the Greenwood Fissure. The ore of the upper bed preserves the nodular character of the limestone host. Ore consists of about 60% pyrite, 22% sphalerite, 8% galena, minor chalcopyrite and practically no gangue minerals. The lower bed ore is massive with an irregular bottom contact, as the underlying quartzite has been irregularly replaced by pyrite and sphalerite. The ore is unoxidized. The Raymond and Ely vein in the Prospect Mountain Quartzite strikes parallel to the Greenwood Fissure. The Greenwood ore occurs chiefly in Pioche Shale. The Black Ledge vein of quartz and sphalerite was also mined yielding 12-20% zinc and 5-21 ounces of silver per ton. The Raymond and Ely vein system splits eastward into two branches: the Meadow Valley vein and the Burke Vein. The largest and richest ore shoot in the vein occurred just below the Pioche Shale within about 400 feet of the Yuba Dike. The complex sulfide ore was of no value until selective flotation was invented. The ore bed was mined for more than 10,000 feet along an east west channel 100 to 1800 feet wide. Ore body terminates against the frontal fault. The hanging wall was unsuccessfully explored to a depth of 2500 feet.
Most gold came from the Combined Metals Mine.
On Treasure Hill, the workings explore a series of faults and shears and the north end of the Yuba dike, a principal contributor to the mineralization of the area. Much of the fault breccia shows milling texture with jarosite and iron-manganese oxides coating most exposed surfaces. The quartzite ranges from white to grey-rose colored with prominent banding. Pods of very fine-grained argentiferous minerals along with galena and other sulfides are disseminated throughout the breccia. Yellow oxides are also common on exposed surfaces. Abundant sericite is present. Locally the breccia zones are silicified and abundant gossan occurs where ore minerals have weathered out. Late opaline silica is deposited on fracture surfaces and iron sulfides have altered to specular hematite. Euhedral quartz crystals line cavities. Quartz vein material which fills fault fissures exhibits brecciation and is recemented with silica, and contains bands of finely disseminated grey sulfides.
The Raymond and Ely, Meadow Valley, and Burke veins strike roughly east-west and dip 50 degrees south. Oxidized silver ore in the quartzite decreased in grade eastward and downward. The Meadow Valley vein was mined continuously for 2000 feet to a depth of 1,200 feet. Average ore thickness was 2-3 feet. Galena and sphalerite are increasingly abundant in the lower levels. Rich silver-lead ore was mined from the Yuba Dike. Three or more cross veins strike northeast at 45 degrees to the principal veins. The "quartzite fissures" are veins with filling of loose rubble of angular quartzite fragments to breccia cemented by lead carbonate, limonite, and jarosite. The quartzite fissures strie N15-20W.

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	01-JAN-2005	LaPointe, D.D.	Nevada Bureau of Mines and Geology
Editor	01-SEP-2007	Schruben, Paul G.	U.S. Geological Survey	Converted from S&A FileMaker format to Oracle. Edit checks on rocks, units, and ages with Geolex search, and other fields.

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

External references

Wikidata: Q49440647 (Pioche Mine)

Maps centered on this site

Authoritative Nevada resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.