Mineral Ridge Mine

Producer in Esmeralda county in Nevada, United States with commodities Gold, Silver

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	10310539
MRDS ID	W002901
Record type	Site
Current site name	Mineral Ridge Mine
Alternate or previous names	Drinkwater pit, Gold Wedge A pit, Gold Wedge B pit, Gold Wedge C pit, Mary-LC pit, Gordon Brodie pit, Mary-Liz pit, Unnamed pit, old Mary - Drinkwater Underground Mine
Related records	60001657

Comments on the site identification

All material from MRDS record No. W002901 has been incorporated into this new record .
Mineral Ridge (See individual deposits)

Geographic coordinates

Geographic coordinates:	-117.70509, 37.79411 (WGS84)
Elevation	2070
Relative position	The mine is located about 20 miles south of the railroad siding at Blair Junction and about 40 km WNW of Goldfield.

Site location context

Political divisions (FIPS codes)

Esmeralda(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Silver Peak(quadrangle 1:24,000 scale)

Goldfield(quadrangle 1:100,000 scale)

Goldfield(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Ralston-Stone Cabin Valleys(hydrologic unit)

Central Nevada Desert Basins(hydrologic accounting unit)

Central Nevada Desert Basins(hydrologic subregion)

Great Basin(hydrologic region)

Geographic areas

Country	State	County
United States	Nevada	Esmeralda

Public Land Survey System information

Meridian	Township	Range	Section	Fraction	State
Mount Diablo	002S	038E	01, 12		Nevada
Mount Diablo	002S	039E	06		Nevada

Comments on the location information

The Mineral Ridge Mine is located on the northeastern flank of the Silver Peak Range, 4 miles northwest of the town of Silver Peak and
32 miles west of Tonopah in Esmeralda County, Nevada. The property consists of 54 patented and 110 unpatented mining claims totaling nearly 2,685 acres, or 4.2 square miles.

Commodities

Commodity	Importance
Gold	Primary
Silver	Secondary

Comments on the commodity information

Ore Materials: native gold, pyrite, galena
Gangue Materials: quartz, alaskite

Materials information

Materials	Type of material
Gold	Ore
Pyrite	Ore
Galena	Ore
Quartz	Gangue

Alteration

(Local) Secondary sulfides have formed acompanying the decomposition of diorite.

Mineral occurrence model information

Model code	150
USGS model code	25c
Deposit model name	Epithermal vein, Comstock
Mark3 model number	16

Host and associated rocks

Host or associated

Host

Rock type

Sedimentary Rock > Carbonate > Limestone

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

Host or associated

Host

Rock type

Plutonic Rock > Granitoid > Alkali-Granite (Alaskite)

Stratigraphic age (youngest)	Jurassic
Stratigraphic age (oldest)	Cretaceous

Host or associated Host

Rock type Plutonic Rock > Pegmatite

Host or associated	Host
Rock type	Plutonic Rock > Pegmatite

Host or associated

Associated

Rock type

Metamorphic Rock > Metasedimentary Rock > Slate

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

Host or associated

Associated

Rock type

Metamorphic Rock > Metasedimentary Rock > Quartzite

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

Host or associated

Associated

Rock type

Plutonic Rock > Mafic Intrusive Rock > Diorite

Stratigraphic age (youngest)	Jurassic
Stratigraphic age (oldest)	Cretaceous

Host or associated Associated

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

Stratigraphic age (youngest) Tertiary
Host or associated Associated

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

Stratigraphic age (youngest) Tertiary
Host or associated Associated

Rock type Volcanic Rock (Aphanitic) > Mafic Volcanic Rock > Basalt

Stratigraphic age (youngest) Tertiary
Host or associated Associated

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

Stratigraphic age (youngest) Tertiary
Host or associated Associated

Rock type Sedimentary Rock > Mixed Clastic/Volcanic Rock

Rock type qualifier volcanic sediments

Stratigraphic age (youngest) Tertiary
Host or associated Associated

Rock type Sedimentary Rock

Rock type qualifier lacustrine sediments

Stratigraphic age (youngest) Tertiary
Host or associated Associated

Rock type Sedimentary Rock > Coal

Stratigraphic age (youngest) Quaternary
Host or associated Associated

Rock type Volcanic Rock (Aphanitic) > Mafic Volcanic Rock > Basalt

Stratigraphic age (youngest) Quaternary
Host or associated Associated

Rock type Unconsolidated Deposit > Alluvium

Stratigraphic age (youngest) Pleistocene

Stratigraphic age (oldest) Holocene

Nearby scientific data

(1)	-117.70509, 37.79411	ListMap

Economic information

Geologic structures

Type of structure	Local
Structure description	NW-, EW-, and NS-trending faults.
Type of structure	Regional
Structure description	The Silver Peak Mountain Range lies in the southern Great Basin within the Walker Lane structural corridor. NW-SE BELT OF FOLDED, FAULTED TERTIARY SEDS E OF SIERRAS, S TO MOJAVE, N TO N. NEVADA

Ore body information

General form lenticular

General form	lenticular

Controls for ore emplacement

Ore is controlled by lithology, occurring in quartz lenses associated with the pegmatitic phase of alaskite. Ore is apparently also controlled by a NNW-trending structure.

Comments on the geologic information

RECENT FAULT ACTIVITY; CRUSHING POST ORE. PLEIST-RECENT VALLEY FILL.

Economic information about the deposit and operations

Operation type	Surface-Underground
Development status	Producer
Commodity type	Metallic
Deposit size	Large
Significant	Yes
Discovery year	1864
Discoverer	Robison Brothers
Year of first production	1867

Mining district

District name	Silver Peak District

Land status

Ownership category	BLM Administrative Area
Area name	U. S. Bureau of Land Management Tonopah District
Ownership category	Private

Ownership information

Type Owner-Operator

Owner Golden Phoenix Minerals, Inc.

Year 2001

Type	Owner-Operator
Owner	Golden Phoenix Minerals, Inc.
Year	2001

Comments on the workings information

Old underground workings were later incorporated into numerous open piit.

Comments on other economic factors

Production - 1991: 25 K oz Au, 8 K oz Ag; 1997: 13,793 oz Au, 7907 oz Ag; Nov 2000-2001: (rinse of leach pads) 738.98 oz Au-Ag dore that refined to 440.98 oz Au, 188.8 oz Ag

1997: Drill indicate res.: 42,708 t, 0.081 opt Au

In 1995, reserves were reported as 6800 kilotonnes of ore containing 12.6 kilotonnes of gold
In 2001 the mineable reserves were reported at 2.658 Mt grading 0.079 opt Au, containing 209.2 K oz Au.

See individual deposits listed in David?s database

Comments on development

Gold and silver were first discovered in the Mineral Ridge area in 1864. Intermittent mining operations have occurred from that date to the present. Early production was from underground high-grade gold ores that averaged from 0.243 opt Au to 1.45 opt Au.
In 1989 open pit mining was initiated in the district with ores grading from 0.074 opt Au to 0.12 opt Au. The total production of the district before open pit mining took place was 576,000 ounces of gold.
Mine operations by Mineral Ridge Resources were suspended in December 1997 due to low gold prices and the company went into bankruptcy. On November 8, 2000 Golden Phoenix Minerals purchased the Mineral Ridge gold mine and resumed mining; the mine was active in 2002-2003.

In 2002, Golden Phoenix reported a mineable reserve of 2,658,000 million tons averaging 0.079 ounces gold per ton for a total of 209,200 ounces. The Company began Phase 1 of its business plan to produce gold from the leach pad.)
In 2004, Golden Phoenix Minerals, Inc. planned to increase gold production at its Mineral Ridge Mine with the rehabilitation of the Lone Mountain mill. The mill, which lies just north of Lone Mountain and about 15 miles west of Tonopah, was built in about 1981 to process tailings from the old Tonopah silver district. Golden Phoenix planned to add a gravity and primary crushing circuit to handle the
Mineral Ridge ore. Once milling begins, low-grade ore will continue to be placed onto a leach pad at the mine site, while high-grade ore will be trucked approximately 43 miles to the mill for processing.

Reference information

Bibliographic references

Deposit

Spurr, J E, 1906, Ore Deposits of the Silver Peak Quadrangle, Nevada: USGS Prof. Paper 55, 174 p.
Deposit

Nolan, T. B., 1936, Nonferrous-Metal Deposits; USGS Bull. 871, p. 60
Deposit

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

Lincoln, F C, 1923, Mining Districts and Mineral Resources of Nevada: Reno p. 80-81.
Deposit

Amer. Mines (1996), 1995 thru Amer. Mines (2001), 2000
Deposit

BLM Claims Microfiche, 1999
Deposit

Goldfield Land Status, 1978
Deposit

NBMG MI-89 thru MI-99.
Deposit

Environmental Assessment, 1996
Deposit

Amer. Mines (1991-92), 1991 thru Amer. Mines (2001), 2000.
Deposit

Quarterly Rep. 5/15/01
Deposit

www.golden-phoenix.com; NBMG Bull 78
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

2005 report on the Mineral Ridge Mine at http://www.golden-phoenix.com/documents/MRPDF.pdf
Deposit

Golden Phoenix Minerals, Inc. press release, 12/1/2004

General comments

Subject category	Comment text
Deposit	The Mineral Ridge property encompasses 4 separate economically mineable gold deposits. The mine reserve, at a 0.035 opt Au cut off grade, is 2,658,340 tons averaging 0.079 opt for 209,226 contained ounces of gold. This reserve is contained in a total resource of 8,314,000 tons averaging 0.061 opt gold (at a 0.02 opt Au cutoff grade) for a total of 506,000 ounces gold. The rocks in the Mineral Ridge area consist of Precambrian metasediments and metamorphosed Tertiary granodiorite which have been cut by numerous shallow dipping faults that host the gold deposits. The gold is found in sheeted zones of thick quartz veins, which nearly parallel the current surface topography. The gold deposits are in quartz lenses in the limestones and probably are genetically related to the late siliceous phase of the alaskite intrusive. Native gold is finely disseminated in the quartz and is also associated with scattered sulfides in the lenses. Mineral Ridge is an anticlinal dome that has been interpreted as an uplifted metamorphic core complex where unmetamorphosed and unfolded Cambrian strata are in detachment-fault contact with underlying deformed granitoids and Precambrian metamorphic rocks of the core complex. Auriferous quartz lenses of the central gold-quartz district are concordant with foliation in the Precambrian Wyman Formation host rock. Transitional contacts were observed between quartz and alaskite (commonly pegmatitic), and between alaskite and peraluminous two-mica granite, strongly suggesting that the alaskite, quartz, and ore metals were derived hydrothermally from residual granite melt and aqueous fluids. Gold occurs as free disseminations and in clots associated with pyrite, galena, sphalerite, and arsenopyrite. The local shallow abundance of quartz lenses permits underground or open-pit mining. Considering the scattered gold distribution, coarse nature of the gold, and common absence of visible ore controls within quartz lenses, the most economically viable method is to mine and process large volumes of quartz-rich rock from mineralized areas. The Mineral Ridge project consists of several gold deposits, which have been defined by drilling and some have been partially mined. The Drinkwater Deposit is the largest known ore deposit and is located on the northeastern side of the metamorphic and intrusive core complex. It was partially mined by underground methods from the 1860s to the early 1940s and by open pit methods from 1989 to 1999. The ore zones in the Drinkwater deposit have a general strike of N45W and dips about 20 to 25 degrees to the northeast. Drill defined ore zones have a strike length of more than 2500 feet and down dip width of 2000 feet. Two or more gold-bearing shear zones are present at the central portion of the deposit with an individual ore zone thickness of 5 to 40 feet and an overall thickness of more than 100 feet. The Mary deposit is also located on the northeastern side of the metamorphic and intrusive complex and east of the Drinkwater deposit. It is the second largest known deposit on Mineral Ridge. This deposit was partially mined by underground methods before the 1940s along with the Drinkwater deposit, but it was not touched by the recent op n-pit mining operations. Ore zones in the Mary deposit have a similar strike and dip as those in the Drinkwater deposit with a drill controlled strike length of over 2000 feet and down-dip with of 1500 feet. These ore zones are thinner and less continuous, but tend to be higher in gold grade than those in the Drinkwater deposit.
Deposit	the Gold Wedge deposit is located at the top of the Mineral Ridge and the metamorphic and intrusive core complex, and southwest of the Drinkwater deposit. It consists of several small horizontal ore bodies, which have been mined by both underground and open-pit methods. Any remaining resources in this deposit are not available for further mining as the location has been utilized for the leach pads and processing facilities. the Brodie deposit is also located on the top of the Mineral Ridge and the metamorphic intrusive core complex, and south of the Gold Wedge deposit. It is a small deposit with nearly horizontal ore zones. The deposit has been partially mined in the past, but there still remains a small drill-defined reserve. Ore zones in this deposit are still open in several directions, which indicates a potential to increase the reserve. the Solberry and Blue Lite deposits are small satellite deposits located southwest of the Gold Wedge deposit. There is a small drill defined reserve in these deposits.

Subject category

Comment text

Deposit

The Mineral Ridge property encompasses 4 separate economically mineable gold deposits. The mine reserve, at a 0.035 opt Au cut off grade, is 2,658,340 tons averaging 0.079 opt for 209,226 contained ounces of gold. This reserve is contained in a total resource of 8,314,000 tons averaging 0.061 opt gold (at a 0.02 opt Au cutoff grade) for a total of 506,000 ounces gold. The rocks in the Mineral Ridge area consist of Precambrian metasediments and metamorphosed Tertiary granodiorite which have been cut by numerous shallow dipping faults that host the gold deposits. The gold is found in sheeted zones of thick quartz veins, which nearly parallel the current surface topography. The gold deposits are in quartz lenses in the limestones and probably are genetically related to the late siliceous phase of the alaskite intrusive. Native gold is finely disseminated in the quartz and is also associated with scattered sulfides in the lenses.

Mineral Ridge is an anticlinal dome that has been interpreted as an uplifted metamorphic core complex where unmetamorphosed and unfolded Cambrian strata are in detachment-fault contact with underlying deformed granitoids and Precambrian metamorphic rocks of the core complex. Auriferous quartz lenses of the central gold-quartz district are concordant with foliation in the Precambrian Wyman Formation host rock. Transitional contacts were observed between quartz and alaskite (commonly pegmatitic), and between alaskite and peraluminous two-mica granite, strongly suggesting that the alaskite, quartz, and ore metals were derived hydrothermally from residual granite melt and aqueous fluids. Gold occurs as free disseminations and in clots associated with pyrite, galena, sphalerite, and arsenopyrite. The local shallow abundance of quartz lenses permits underground or open-pit mining. Considering the scattered gold distribution, coarse nature of the gold,
and common absence of visible ore controls within quartz lenses, the most economically viable method is to mine and process large volumes of quartz-rich rock from mineralized areas.

The Mineral Ridge project consists of several gold deposits, which have been defined by drilling and some have been partially mined. The Drinkwater Deposit is the largest known ore deposit and is located on the northeastern side of the metamorphic and intrusive core complex. It was partially mined by underground methods
from the 1860s to the early 1940s and by open pit methods from 1989 to 1999. The ore zones in the Drinkwater deposit have a general strike of N45W and dips about 20 to 25 degrees to the northeast. Drill defined ore zones have a strike length of more than 2500 feet and down dip width of 2000 feet. Two or more gold-bearing shear zones are present at the central portion of the deposit with an individual ore zone thickness of 5 to 40 feet and an overall thickness of more than 100 feet. The Mary deposit is also located on the northeastern side of the metamorphic and intrusive complex and east of the Drinkwater deposit. It is the second largest known deposit on Mineral Ridge. This deposit was partially mined by underground methods before the 1940s along with the Drinkwater deposit, but it was not touched by the recent op n-pit mining operations. Ore zones in the Mary deposit have a similar strike and dip as those in the Drinkwater deposit with a drill controlled strike length of over 2000 feet and down-dip with of 1500 feet. These ore zones are thinner and less continuous, but tend to be higher in gold grade than those in the Drinkwater deposit.

Deposit

the Gold Wedge deposit is located at the top of the Mineral Ridge and the metamorphic and intrusive core complex, and southwest of the Drinkwater deposit. It consists of several small horizontal ore bodies, which have been mined by both underground and open-pit methods. Any remaining resources in this deposit are not
available for further mining as the location has been utilized for the leach pads and processing facilities.

the Brodie deposit is also located on the top of the Mineral Ridge and the metamorphic intrusive core complex, and south of the Gold Wedge deposit. It is a small deposit with nearly horizontal ore
zones. The deposit has been partially mined in the past, but there still remains a small drill-defined reserve. Ore zones in this deposit are still open in several directions, which indicates a potential to increase the reserve.

the Solberry and Blue Lite deposits are small satellite deposits located southwest of the Gold Wedge deposit. There is a small drill defined reserve in these deposits.

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	27-JUN-2002	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.

Current status (per MSHA)

Status	Active since 06/10/2012
MSHA mine ID	2602302
Mine name (MSHA)	Mineral Ridge Mine
Current operator	Mineral Ridge Gold, LLC
Current controller (parent)	Capstone Commodities DMCC
Mine type	Surface (Metal / non-metal)

Inferred by coordinate + name similarity (1264 m, 1.00 match). Confirm against MSHA if precision matters — non-USGS-curated cross-references may occasionally point at a neighbouring mine.

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