Manhattan Gold Mine

Past Producer in Nye county in Nevada, United States with commodities Silver, Gold, Antimony, Arsenic, Fluorine-Fluorite

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	10310361
Record type	Site
Current site name	Manhattan Gold Mine
Alternate or previous names	Big Four Mine, Reilly Mine, Big Pine Mine, Little Grey Mine, East Pit, West Pit
Related records	10044292

Comments on the site identification

This record covers a mineralized area described earlier by MRDS records for the historic Big Four, Reilly, Big Pine,and Little Grey mines as well as other Manhattan District mines which are encompassed by the current mine record, and from which all pertinent material has been incorporated into the current record, but those records should remain in the database for historic reference.

Geographic coordinates

Geographic coordinates:	-117.0562, 38.53132 (WGS84)
Elevation	2150
Relative position	The Manhattan gold mine is s located in the central part of the Manhattan mining district about 12 miles south of Round Mountain, 40 miles northeast of Tonopah, on the western flank of the Toquima Range

Site location context

Political divisions (FIPS codes)

Nye(county)

Nevada(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Manhattan(quadrangle 1:24,000 scale)

Ione Valley(quadrangle 1:100,000 scale)

Tonopah(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Southern Big Smoky Valley(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	Nye

Public Land Survey System information

Meridian	Township	Range	Section	Fraction	State
Mount Diablo	008N	044E	19 20 21		Nevada

Comments on the location information

The mine area is centered about one mile ESE of the townsite of Manhattan, up canyon from the townsite.

Commodities

Commodity	Importance
Silver	Primary
Gold	Primary
Antimony Critical	Tertiary
Arsenic Critical	Tertiary
Fluorine-Fluorite Critical	Tertiary

Comments on the commodity information

Commodity Info: Fineness of gold averages about 700.
Ore Materials: native gold and silver, stibnite, microscopic arsenopyrite, realgar, fluorite
Gangue Materials: calcite, drusy quartz, adularia, pyrite, clay, iron oxide minerals; rare fluorite and barite

Materials information

Materials	Type of material
Gold	Ore
Silver	Ore
Stibnite	Ore
Arsenopyrite	Ore
Realgar	Ore
Fluorite	Ore
Quartz	Ore
Adularia	Ore
Pyrite	Ore
Clay	Ore
Fluorite	Ore
Barite	Ore
Calcite	Gangue

Alteration

(Local) Host rocks in the mine area are not strongly altered hydrothermally. Quartz/host rock contacts are sharply defined.

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

Metamorphic Rock > Phyllite

Rock type qualifier

sandy

Rock unit name

Gold Hill Formation

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

Host or associated

Host

Rock type

Sedimentary Rock > Carbonate > Limestone

Rock unit name

White Caps Limestone

Stratigraphic age (youngest)	Late Cambrian

Host or associated

Associated

Rock type

Metamorphic Rock > Schist

Rock unit name

Gold Hill Formation

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

Host or associated

Associated

Rock type

Metamorphic Rock > Metasedimentary Rock > Quartzite

Rock unit name

Gold Hill Formation

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

Nearby scientific data

(1)	-117.0562, 38.53132	ListMap

Economic information

Geologic structures

Type of structure	Regional
Structure description	A series of thrust sheets that generally dip to the south have affected rocks in the mine area. The Manhattan gold deposit occurs within a NW-trending, NW-plunging faulted antiform.
Type of structure	Local
Structure description	Reilly Fault (ENE), Jumping Jack Fault (NE), Twin Faults (ENE), Big Pine Fault (ENE), and joints associated with the Brugher Fault trend (NE), joints associated with the Little Grey Fault trend (NW), Little Grey Cross Fault (E-W) and joints associated with other unnamed fault trends, all cut through the mine area.

Ore body information

General form Tabular to irregular

General form	Tabular to irregular

Controls for ore emplacement

Ore in the West Pit orebody follows faults parallel to the NW-trending Little Grey Fault with size and frequency of ore decreasing laterally away from the Little Grey Fault. The East Pit orebody is controlled by a poorly-defined NW-trending zone of abundant folds and associated faults associated with the axis of what is termed the ?Big Four Fold?.

Comments on the geologic information

The oldest rocks in the Manhattan district are phyllite, schist, quartzite and limestone units of the Cambrian Gold Hill Formation. Of these, a sandy phyllite unit of the Gold Hill Formation has been the most productive gold mineralized unit in the mine area. Locally in the district, the Gold Hill Formation has been overthrust by younger Ordovician sedimentary rocks including the Zanzibar limestone, argillite and quartzite units. The mines in the district are located along the southern margin of the Manhattan caldera, which formed about 25 million years ago.
Fluid inclusion data indicates homogenization temperatures of 200-235 degrees C at salinities of 0.3-0.8 wt % NaCl equivalent.

Economic information about the deposit and operations

Operation type	Surface-Underground
Development status	Past Producer
Commodity type	Both
Deposit size	Small
Significant	Yes
Discovery year	1868
Year of first production	1868
Year of last production	1993
Production years	1860s; 1905-1947; 1973-1993

Mining district

District name	Manhattan District

Land status

Ownership category	National Forest
Area name	Tonopah USFS Ranger District
Ownership category	BLM Administrative Area
Area name	Tonopah BLM field station
Ownership category	Private

Ownership information

Type Owner

Owner Smoky Valley Common Operation

Year 2004
Type Operator

Owner Round Mountain Gold Corporation

Year 2004

Type	Owner
Owner	Smoky Valley Common Operation
Year	2004

Type	Operator
Owner	Round Mountain Gold Corporation
Year	2004

Comments on the workings information

At the historic Nevada Manhattan/Nevada Consolidated Mine, workings consist of a 500 foot vertical shaft with five levels. The entire district is developed by numerous underground and surface workings, including several open pits. The currently described mine was developed by two open pits: the East Pit (1500 feet by 1000 feet) and the West Pit (1200 feet by 300 feet) developed in the 1980s by Echo Bay Mines Ltd.

Comments on other economic factors

Lode gold production for the Manhattan District through 1967 was about 193,000 ounces of gold. From 1987 through 1989, the current mine produced more than 62,000 ounces of gold, after which production for 1990-1993 was included with that of Round Mountain Gold Mine to the north.
In 1997, proven and probable reserves were reported at 1.7 million tons of ore grading 0.13 opt gold.

Comments on development

The central Manhattan Mining District has had a long and productive mining history. The area was first prospected for silver and copper in the 1860s with some small production of ore that was shipped to Belmont. The next phase of exploration began in 1905 when the rich lode and placer gold deposits were discovered and mined more or less continuously until 1947. Suma Corporation acquired the property in 1967 but did little exploration until 1972 when they launched a major mapping, sampling, and drilling program to delineate a bulk-mineable heap-leachable gold orebody in the district. By 1973, more than 200,000 tons of ore grading 0.10 opt gold had been delineated and 6500 tons of it was mined and heap-leached later that year, with poor recovery due to the coarseness of the gold. Continued drilling in 1974 and 1975 defined more ore in the East and West pit areas increasing the proven reserves to more than 400,000 tons grading 0.075 opt gold, of which 60,000 were heap-leached in 1974. In 1977, Summa sold the property to Houston Oil & Minerals Company ( later Tenneco/CanAm/ Echo Bay Minerals). More drilling in 1977-1979 increased reserves to 800,000 tons grading 0.09 opt gold, which was considered sufficient to justify construction of a 750 tpd mill from 1981 to 1983 during which time mining was suspended pending mill feasibility studies. In 1984,
Tenneco (Echo Bay) resumed mining from the East and the West Pits, which incorporated several smaller open pits from earlier Summa Corp. mining activity. They operated the two open pits for several years using a combination gravity circuit and flotation-cyanidation circuit in the mill. Heap leach operations were also in use from 1988 through 1990. Mining ceased in 1990, shortly after Round Mountain Gold Corporation acquired the site. Milling operations and tailings deposition stopped later that same year. Heap leaching and gold recovery continued until 1993 when heap closure activities started with biological detoxification of the spent ore. Reclamation of the Manhattan mine site from 1994 through 2001 earned Round Mountain Gold Corporation the BLM?s Hardrock Mineral Environmental award in 2004 for its innovative reclamation designs and new technique for treating water used in the mining process.
Both Calais Resources and Royal Standard Minerals are now exploring and developing nearby gold mining properties in the Manhattan District (2005).

Reference information

Bibliographic references

Deposit

Kral, V.E., 1951, Mineral Resources of Nye Co.: Nev. Bur. of Mines and Geol., Bull. 50, p. 125
Deposit

Ferguson, H.G., 1924, Geol. and ore deposits of the Manhattan District: USGS Bull 723, p. 151-153.
Deposit

NBMG, MI-1993-MI-2004.
Deposit

Shawe and others, 1986, Ages of igneous and hydrothermal events in the Round Mountain and Manhattan gold district, Nye County, Nevada, Econ. Geol., vol. 81, p. 388-407.
Deposit

Maddry and others, 1987, Geology of the Manhattan Gold deposit Nye County, Nevada, in Bulk Mineable Precious Metal Deposits of the Western US, GSN Symposium Proceedings.
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.

General comments

Subject category	Comment text
Deposit	In the main mined area, gold occurs in drusy quartz-adularia veinlets in brittle, fractured, faulted sandy phyllite of the Gold Hill Formation. Native gold is coarse-grained (.04-10 mm) and occurs on fractures as discrete free crystals and masses. Both the East and West Pit orebodies are characterized by a coarse stockwork of fractures lined by gangue minerals and free gold. Frctures generally range in thickness from 0.16 to 1.3 cm. At the historic Nevada Manhattan/Nevada Consolidated Mine workings, mineralization is localized along the Mud Fault. Ore is controlled by a small north-striking fault in the east part of the mine, and by small fault fissures in the west part of the mine. Gold occurs in solution channels forming rare specks of wire in a muddy matrix of iron and manganese oxides (western part). There is also some replacement along bedding, thinning out away from fissures.

Subject category

Comment text

Deposit

In the main mined area, gold occurs in drusy quartz-adularia veinlets in brittle, fractured, faulted sandy phyllite of the Gold Hill Formation. Native gold is coarse-grained (.04-10 mm) and occurs on fractures as discrete free crystals and masses. Both the East and West Pit orebodies are characterized by a coarse stockwork of fractures lined by gangue minerals and free gold. Frctures generally range in thickness from 0.16 to 1.3 cm.

At the historic Nevada Manhattan/Nevada Consolidated Mine workings, mineralization is localized along the Mud Fault. Ore is controlled by a small north-striking fault in the east part of the mine, and by small fault fissures in the west part of the mine. Gold occurs in solution channels forming rare specks of wire in a muddy matrix of iron and manganese oxides (western part). There is also some replacement along bedding, thinning out away from fissures.

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	01-NOV-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.

Current status (per MSHA)

Status	Intermittent since 09/12/2024
MSHA mine ID	2602658
Mine name (MSHA)	Manhattan Gulch
Current operator	Manhattan Gulch, LLC
Current controller (parent)	Manhattan Gulch Partners LLC
Mine type	Surface (Metal / non-metal)

Inferred by coordinate + name similarity (1818 m, 0.83 match). Confirm against MSHA if precision matters — non-USGS-curated cross-references may occasionally point at a neighbouring mine.

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Maps centered on this site

Authoritative Nevada resources

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