Three Hills Prospect

Site Name

Primary: Three Hills Prospect
Secondary: Tonopah Project
Secondary: part of Hasbrouck-Three Hills project

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Commodity

Primary: Silver
Primary: Gold

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Location

State: Nevada
County: Esmeralda
District: (Gold Mountain District)

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Land Status

Land ownership: Private
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

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Holdings

Not available

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Workings

Not available

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Ownership

Owner Name: Eastfield Resources, Ltd.
Info Year: 2002

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Production

Not available

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Deposit

Record Type: Site
Operation Category: Producer
Deposit Type: vein/lode
Operation Type: Surface-Underground
Year First Production: 1900
Years of Production:
Organization:
Significant: Y

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Physiography

Not available

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Mineral Deposit Model

Model Name: Epithermal vein, Comstock

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Orebody

Form: tabular

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Structure

Not available

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Alterations

Not available

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Rocks

Name: Rhyolite
Role: Host
Age Type: Host Rock
Age Young: Miocene

Name: Tuff
Role: Host
Description: silicic
Age Type: Host Rock
Age Young: Miocene

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Analytical Data

Not available

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Materials

Ore: Gold
Ore: Adularia
Gangue: Quartz

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Comments

Comment (Economic Factors): Reserves at the Three Hills deposit in 1997 were reported as 6.286 million tons of ore grading 0.023 ounces of gold per ton. In 2003, Vista reportedd that the Three Hills property has an indicated resource of 5.7 million tons at a grade of 0.023 ounces of gold per ton. Vista Gold in 2006 reported the following drill-indicated resources for Three Hills, based on an assessment by Mine Development Associates: 5,736,000 tons grading 0.023 ounces of gold per ton for 133,000 contained ounces.

Comment (Workings): surface, old underground

Comment (Commodity): Ore Materials: gold

Comment (Commodity): Gangue Materials: quartz, adularia

Comment (Deposit): The property hosts oxidized, epithermal gold-silver mineralization. It explores a disseminated epithermal, quartz-adularia-type precious metal deposit in the vicinity of historic bonanza-type gold-silver deposits mined in the early 1900s. Exploration work by Eastfield has shown that several targets remain unexplored, including the Ohio, Bermuda and Merton veins. The Ohio vein was mined at plus 50-foot widths up to a fault, which offsets the zone; this offset presents an enticing drill target. Drilling by Eastfield along the surface projection of the Merton vein encountered 10 feet of 0.21 oz/t gold and 8 oz/t silver within an interval of 100 feet of anomalous gold in quartz-adularia stockworks. The main controls on the bonanza mineralization have been traced for approximately one mile west of the historic production and this area is largely unexplored.

Comment (Development): The property was evaluated in 1991-93 at which time it was idle. A new phase of exploration on the property began in 1997. Eastfield owns (via direct ownership and agreement) a 100% interest in 25 patented claims. The Tonopah District, in which the property lies, was one of the preeminent silver producers in the U.S. In the first third of the 1900's 1.8 million oz. gold and 174 million oz. silver were mined at a recovered average grade of 0.21 oz/t gold and 19.7 oz/t silver. Exploration work by Eastfield has shown that several bonanza gold-silver targets remain unexplored, including the Ohio, Bermuda and Merton veins. The Ohio vein was mined at plus 50-foot widths up to a fault, which offsets the zone; this offset presenting a promising drill target. Drilling by Eastfield along the surface projection of the Merton vein encountered 10 feet of 0.21 oz/t gold and 8 oz/t silver within an interval of 100 feet of anomalous gold in quartz-adularia stockworks. the main controls on the bonanza mineralization have been traced for approximately one mile west of the historic production and this area is largely unexplored. In 2003, Vista Gold Corp. purchased both the Three Hills property in the Tonopah district the Hasbrouck property in the Divide district from Newmont Mining Corp. The Three Hills property is owned by Vista Gold Corp. (2004-2006). Vista also controls the Hasbrouck property a few miles south in the Divide District and reports on the two together as their ?Hasbrouck-Three Hills? project although the two deposits are separate and distinct and a few miles apart.

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References

Reference (Deposit): Amer. Mines (1997), 1996 thru Amer. Mines (2000), 1999.

Reference (Deposit): NBMG Map 91, 1st, 2nd, 3rd.

Reference (Deposit): Vista Gold Corp website 2006.

Reference (Deposit): Vista Gold Corp. press release, 3/20/2003, 7/31/2003.

Reference (Deposit): NBMG MI-95 through MI-99.

Reference (Deposit): NBMG OFR 83-11,83-12.

Reference (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.

Reference (Deposit): http://www.eastfieldgroup.com/eastfield/tonopah.html (2001).
URL: http://www.eastfieldgroup.com/eastfield/tonopah.html

Reference (Deposit): Tonopah Land Status, 1978

Reference (Deposit): GSN Spec. Pub. No. 26, 1997.

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Nevada Gold

Nevada has a total of 368 distinct gold districts. Of the of those, just 36 are major producers with production and/or reserves of over 1,000,000 ounces, 49 have production and/or reserves of over 100,000 ounces, with the rest having less than 100,000 ounces. Read more: Gold Districts of Nevada.