Hilltop-Slaven Gold Property

Producer in Lander county in Nevada, United States with commodities Gold, Silver, Copper, Lead, Zinc, Antimony, Tin

Geologic information

Identification information

Deposit ID	10310570
MRDS ID	M231404
Record type	Site
Current site name	Hilltop-Slaven Gold Property
Alternate or previous names	Independence Mine, Victoria Resource Corporation?s property, Hilltop Gold Mine
Related records	10044080

Comments on the site identification

The current record describes an area covered by the Hilltop historic mine deposits described in part by earlier MRDS records M231404 and W702077 from which all material has been incorporated into the current record, as well as additonal new material.

Geographic coordinates

Geographic coordinates:	-116.80621, 40.41574 (WGS84)
Elevation	2040
Relative position	The Hilltop Gold Mine is located about 18 miles SE of the town of Battle Mountain, Nevada.
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Geographic areas

Country	State	County
United States	Nevada	Lander

Public Land Survey System information

Meridian	Township	Range	Section	Fraction	State
Mount Diablo	029N	046E	04	NW, 04	Nevada

Comments on the location information

The Hilltop Gold Mine is located on the east side of Hilltop Ridge in the Northern Shoshone Range.

Commodities

Commodity	Importance
Gold	Primary
Silver	Secondary
Copper	Tertiary
Lead	Tertiary
Zinc	Tertiary
Antimony	Tertiary
Tin	Tertiary

Comments on the commodity information

Ore Materials: free gold, pyrite, chalcopyrite, sphalerite, galena, tetrahedrite, stibnite, auriferous pyrite, auriferous arsenopyrite, cassiterite
Gangue Materials: quartz, pyrite, barite, marcasite, , calcite, fluorite, jasper, iron oxide

Materials information

Materials	Type of material
Gold	Ore
Pyrite	Ore
Chalcopyrite	Ore
Sphalerite	Ore
Galena	Ore
Tetrahedrite	Ore
Stibnite	Ore
Pyrite	Ore
Arsenopyrite	Ore
Cassiterite	Ore
Pyrite	Ore
Barite	Ore
Marcasite	Ore
Calcite	Ore
Fluorite	Ore
Jasper	Ore
Quartz	Gangue

Alteration

(Local) There have been two main alteration episodes: one pre-ore consisting of pervasive quartz-sericite-pyrite, and one coeval with gold deposition pervasive silicification, bleaching, baritization, and alunitization. Hydrothermal alteration of the Valmy Formation is predominantly bleaching (removal of organic carbon) and recrystallization/silicification resulting from the emplacement of Tertiary igneous intrusions. Tertiary igneous units exhibit typical phyllic alteration with local argillic alteration.

Mineral occurrence model information

Model code	75
USGS model code	19c
BC deposit profile	E03
Deposit model name	Distal disseminated Ag-Au
Mark3 model number	18

Host and associated rocks

Host or associated

Host

Rock type

Sedimentary Rock > Chemical Sediment > Chert

Rock type qualifier

brecciated

Rock unit name

Valmy Formation

Stratigraphic age (youngest)	Ordovician

Host or associated

Host

Rock type

Sedimentary Rock > Clastic Sedimentary Rock > Argillite

Rock unit name

Valmy Formation

Stratigraphic age (youngest)	Ordovician

Host or associated

Host

Rock type

Sedimentary Rock > Clastic Sedimentary Rock > Siltstone

Rock type qualifier

minor

Rock unit name

Valmy Formation

Stratigraphic age (youngest)	Ordovician

Host or associated

Host

Rock type

Metamorphic Rock > Metasedimentary Rock > Quartzite

Rock type qualifier

minor

Rock unit name

Valmy Formation

Stratigraphic age (youngest)	Ordovician

Host or associated Associated

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

Rock type qualifier dacite porphyry intrusives
Host or associated Associated

Rock type Plutonic Rock > Porphyry

Rock type qualifier dacite porphyry intrusives
Host or associated Associated

Rock type Plutonic Rock > Granitoid > Quartz Monzonite

Rock type qualifier altered quartz monzonite porphyry
Host or associated Associated

Rock type Plutonic Rock > Porphyry

Rock type qualifier altered quartz monzonite porphyry

Host or associated	Associated
Rock type	Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Dacite
Rock type qualifier	dacite porphyry intrusives

Host or associated	Associated
Rock type	Plutonic Rock > Porphyry
Rock type qualifier	dacite porphyry intrusives

Host or associated	Associated
Rock type	Plutonic Rock > Granitoid > Quartz Monzonite
Rock type qualifier	altered quartz monzonite porphyry

Host or associated	Associated
Rock type	Plutonic Rock > Porphyry
Rock type qualifier	altered quartz monzonite porphyry

Nearby scientific data

(1)	-116.80621, 40.41574	ListMap

Geologic structures

Type	Description	Terms
Local	Hilltop Mine Fault
Regional	The Hilltop deposit falls within the Battle Mountain-Eureka mineral belt.

Ore body information

General form tabular

General form	tabular

Controls for ore emplacement

Two sub-parallel west-dipping faults served as conduits for mineralization. There has been brecciation of host rocks along a fault zone.

Economic information

Economic information about the deposit and operations

Operation type	Surface
Development status	Producer
Commodity type	Metallic
Deposit size	Small
Significant	Yes
Year of first production	1907
Year of last production	1919

Mining district

District name	Hilltop District
District name	Bateman Canyon
District name	Slaven Canyon

Land status

Ownership category	Private
Ownership category	BLM Administrative Area
Area name	Battle Mountain BLM administrative district

Ownership information

Type Owner-Operator

Owner Placer Dome

Year 2003
Type Owner-Operator

Owner Victoria Resource Corporation (surrounding area)

Year 2003

Type	Owner-Operator
Owner	Placer Dome
Year	2003

Type	Owner-Operator
Owner	Victoria Resource Corporation (surrounding area)
Year	2003

Comments on the workings information

The historic mine area was developed by numerous shafts, adits and prospect pits and trenches. The Hilltop Mine has been developed as an open pit, heap leach project.

Comments on other economic factors

There was a small amount of early production from 1907 until about . In 2003, the Hilltop Mine property of Placer Dome was estimated to contain nearly a gold resource of almost 2 million ounces in material with an average grade of approximately 0.028 ounces of gold per ton. There was an open pit heap leach operation begun on the property, but the amount of production, if any, is unknown.

Comments on development

In 1907, high-grade gold ore was discovered in Hilltop Canyon and the Hilltop Mine was located about the same time. Hilltop Mining and Reduction Company built a 10-stamp mill in 1910; in 1914 it was converted to a cyanidation mill. Gulf drilled the Hilltop Property from 1981 to 1983 on 200-ft spacings. Ruskin Developments acquired the property from Gulf Mineral Resources Co. in May, 1984 with intentions of proving up drill-indicated reserves and do a feasibility study based on findings. In summer of 1986, U.S. Precious Metals, Inc. of Vancouver decided to exercise its option to earn 50% of the Hilltop Property with an open pit heap leach project. Noranda became involved in the development in 1987 with an option to earn a 50% interest by drilling and producing a feasibility study over the next 12 months while U.S. Precious Metals, Inc. of Vancouver maintained a 25% ownership and Ruskin Developments a 75% interest. The Hilltop-Slaven property consists of 32 complete and 18 partial sections, plus 19 unpatented mining claims, which constitutes a large portion (approximately 45 square miles or 11,600 hectares) of Newmont's checkerboard private landholdings. Checkerboard refers to every odd-numbered section for 20 miles on either side of the original Central Pacific Railroad route, which traverses the state of Nevada generally east to west. These sections cover much of the NW trend of the Battle Mountain Gold Belt where it crosses the Northern Shoshone Range. Several sections of the Hilltop-Slaven property are adjacent to and partially surround the Hilltop Mine property of Placer Dome, which has a gold resource of almost 2 million ounces at approximately 0.028 ounces of gold per ton. The Battle Mountain Gold Belt is made up of a myriad of historic mines, which cover every section of the area. During 2003, Victoria will focus on structural mapping and mapping of the Eocene dikes that are abundant as N-S, WNW, and NW swarms within the Battle Mountain Gold Belt. These dike swarms are spatially, if not genetically, associated with gold concentrations at Hilltop, Cortez, Gold Acres, and other mines within the gold belt.

Reference information

Bibliographic references

Deposit

NBMG Mining District File 153, Numerous press clippings
Deposit

Lisle, R.E. and Desrochers, G.J., 1988, Geology of the Hilltop Gold Deposit, Lander County, Nevada in GSN Precious Metals Symposium Technical Volume.
Deposit

Bonham, H.F., 1986, NBMG Map 91
Deposit

Bonham, H.F., 1988, in NBMG MI-1987
Deposit

NBMG, 1994, MI-1993
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

Kelson, C.R., Keith, J.D., Christiansen, E.H., and Meyer, P.E., 2000, Mineral paragenesis and depositional model of the Hilltop gold deposit, Lander County, NV, in Cluer, J.K., Price, J.G., Struhsacker, E.M., Hardyman, R.F., and Morris, C.L., eds., Geology and ore Deposits 2000: The Great Basin and Beyond: Geological Society of Nevada Symposium Proceedings, Reno/Sparks, May 2000, p.1107-1132.
Deposit

http://www.arizonastar.com/337/Hilltop-Slaven_Property.htm
[http://www.arizonastar.com/337/Hilltop-Slaven_Property.htm]

General comments

Subject category	Comment text
Deposit	Gold mineralization is associated with sulfide minerals, which are hosted by a brecciated chert unit occupying the hanging wall of a fault. Deposit occurs in both concordant and discordant breccias and in narrow quartz veins. The deposit is distinguished by the occurrence of gold mineralization in quartz-carbonaceous matter-sulfide breccia matrix in a non-calcareous host rock. Veins strike N-S and dip steeply west. In the historic Hilltop workings, the deposit was described as shattered quartzite seamed with stringers of quartz and iron oxide carrying a large amount of free gold. Locally small bodies of pyrite and galena occur in the fracture planes of quartzite and minute stringers of a gray metallic mineral said to contain bismuth. Assays show silver equal by weight to gold. The quartzite near the ore is impregnated with pyrite and locally decomposed to a soft white claylike substance carrying high values in gold. Two sub-parallel west-dipping faults served as conduits for mineralization. Thrust faulting followed by Basin-and-Range style extension along both faults before and during mineralization created a highly permeable megabreccia (the main zone) which received later igneous intrusions and hydrothermal fluid deposition. A discordant quartz breccia pipe hosts both main zone and porphyry-related(?) mineralization. Initial weak porphyry-style Cu-Mo-Au mineralization throughout the Hilltop area was probably associated with a 41.2?0.5 Ma west-northwest trend of diorite-granodiorite intrusions. The porphyry mineralization is localized around the periphery of the intrusions. Precious metal mineralization within the main zone followed the porphyry event and consists of at least six temporally distinct but spatially overlapping events. Main zone mineralization exhibits characteristics of both high- and low- sulfidation epithermal systems. Gold is associated with silica and arsenopyrite in three of six main zone mineralization events and shows no affinity for a particular host rock type

Subject category

Comment text

Deposit

Gold mineralization is associated with sulfide minerals, which are hosted by a brecciated chert unit occupying the hanging wall of a fault. Deposit occurs in both concordant and discordant breccias and in narrow quartz veins. The deposit is distinguished by the occurrence of gold mineralization in quartz-carbonaceous matter-sulfide breccia matrix in a non-calcareous host rock. Veins strike N-S and dip steeply west. In the historic Hilltop workings, the deposit was described as shattered quartzite seamed with stringers of quartz and iron oxide carrying a large amount of free gold. Locally small bodies of pyrite and galena occur in the fracture planes of quartzite and minute stringers of a gray metallic mineral said to contain bismuth. Assays show silver equal by weight to gold. The quartzite near the ore is impregnated with pyrite and locally decomposed to a soft white claylike substance carrying high values in gold. Two sub-parallel west-dipping faults served as conduits for mineralization. Thrust faulting followed by Basin-and-Range style extension along both faults before and during mineralization created a highly permeable megabreccia (the main zone) which received later igneous intrusions and hydrothermal fluid deposition. A discordant quartz breccia pipe hosts both main zone and porphyry-related(?) mineralization. Initial weak porphyry-style Cu-Mo-Au mineralization throughout the Hilltop area was probably associated with a 41.2?0.5 Ma west-northwest trend of diorite-granodiorite intrusions. The porphyry mineralization is localized around the periphery of the intrusions. Precious metal mineralization within the main zone followed the porphyry event and consists of at least six temporally distinct but spatially overlapping events. Main zone mineralization exhibits characteristics of both high- and low- sulfidation epithermal systems. Gold is associated with silica and arsenopyrite in three of six main zone mineralization events and shows no affinity for a particular host rock type

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	01-FEB-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.