Mining Intelligence and News
United States

Lone Tree Mine

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Categories

Overview

Mine TypeOpen Pit
StageResidual leach
Commodities
  • Gold
  • Silver
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SnapshotThe Lone Tree Project consists of the past-producing Lone Tree mine and processing facility, as well as the nearby Buffalo Mountain deposit and the Brooks open pit mine, which is currently on care and maintenance. Processing infrastructure at Lone Tree includes an autoclave, carbon-in-leach mill, flotation mill, and heap leach facility.

Lone Tree will be the "hub" of the Corporation's Nevada operations as the central processing facility, operations office, assay lab, and warehouse for all sites. I-80 is planning to have minerals from Granite Creek, Ruby Hill, and McCoy-Cove feed the Lone Tree autoclave, once restarted, and minerals from the Buffalo Mountain open pit processed at the Lone Tree heap leach facility. To execute its "hub and spoke" development plan, I-80 is planning, subject to the making of respective positive construction decisions, to begin construction of four new mining operations, advance permitting, and restart the Lone Tree autoclave.

Owners

SourceSource
CompanyInterestOwnership
i-80 Gold Corp. 100 % Indirect
The i-80 Gold Corp. interest in the Lone Tree Project is held through its subsidiary, Dee LLC.

Deposit type

  • Sediment-hosted
  • Epithermal
  • Mesothermal

Summary:

The Lone Tree deposit is characterized as a pluton-related or distal-disseminated Ag-Au deposit. The Lone Tree deposit among others in the Battle Mountain district appears to be related genetically to porphyry systems, even though many deposits do not contain obvious near-surface features that would indicate this connection, mainly because the gold-silver mineralization in these deposits may be over one km away from the causative intrusions. This is why the deposit has been characterized as both “distal disseminated” (to intrusive center). Due to complex tectonic and extension in the region, the mineralization in these deposit types may have substantially different geometric relations to the intrusive centers and hosted in different stratigraphic horizons. The mineralization at Lone Tree occurs in intensely fractured three stratigraphic horizons which is similar in other deposits in the region; however, it is not the same in all deposits. Gold is associated with low Ag:Au (<2:1), As, Sb, Hg and Tl as well as elevated Bi, Mo and W. Gold is hosted in arsenopyrite indicating higher temperatures of ore formation in comparison to typical Carlin-type deposits where gold is hosted in arsenian pyrite.

Gold mineralization occurs as sub-micron sized inclusions within a distinct generation of very fine-grained pyrite and arsenopyrite in the sulfide zone. Evidence gathered to date suggests that the main gold deposition event occurred in a temperature range of 200° to 450° (epithermal to mesothermal). The ore mineralogy shows evidence of two overprinted assemblages reflecting at least two hydrothermal episodes at Lone Tree. Partial oxidation of the main stage mineralization occurred prior to a later, epithermal event characterized by open-space filling textures and weakly auriferous pyrite and marcasite. In the oxidized portions of the deposit, and particularly in the Havallah rocks, gold occurs as micron-sized particles in goethite and limonite. Post-mineral oxidation extends as much as 700 feet down major structures such as the Wayne Zone. No supergene effects or gold remobilization have been proven or documented at the Lone Tree Mine (K.C. Raabe, 1995. The Lone Tree Extension Project, Humboldt County, Nevada).

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

CommodityUnits202320222021202020192018
Gold oz  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe17,48324,253
All production numbers are expressed as metal in doré.

Production Costs

CommodityUnits2022
Credits (by-product) Gold USD  ....  Subscribe
Total cash costs (sold) Gold USD  ....  Subscribe
All-in sustaining costs (sold) Gold USD  ....  Subscribe
** Net of By-Product.

Financials

Units20232022
Revenue M USD  ....  Subscribe  ....  Subscribe

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNameProfileRef. Date
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EmployeesContractorsTotal WorkforceYear
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Aerial view:

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