United States

Granite Creek Project

Click for more information

Categories

Overview

Mine TypeOpen Pit & Underground
StageConstruction
Commodities
  • Gold
Mining Method
  • Truck & Shovel / Loader
  • Overhand Cut & Fill
  • Underhand Cut & Fill
  • Longhole stoping
  • Avoca
Production Start... Lock
Mine Life... Lock
ShapshotThe Granite Creek Project hosts both high-grade open pit and underground mineral resources that remain open for expansion. The underground mine at Granite Creek is permitted and is in development the goal of ramping up mining into 2024. Three deposits being developed with processing at the Lone Tree Facility (autoclave): Granite Creek Mine, Ruby Hill Mine, and Cove Mine.

The Granite Creek Project sold 1,745 ounces of gold and 83,933 tons of mineralized material which were processed by means of third-party ore sales and toll milling agreements, and by heap leaching at the Corporations Lone Tree facility. This material was provided by the project’s underground mining operations during the financial year ended December 31, 2023.

The water treatment plant has been completed and permit has been received in 2024. The installation of de-watering Well 6 is complete and the mobilization of the water treatment plant has started.

i-80 Gold expects to complete a Feasibility Study in 2024.

Owners

SourceSource
CompanyInterestOwnership
i-80 Gold Corp. 100 % Indirect
In April, 2021, i-80 Gold Corp (i-80) through its wholly-owned subsidiary, Premier Gold Mines USA (PGU), acquired Osgood Mining Company LLC (OMC) from Waterton Global Resources Management. OMC being the owner of the Granite Creek Mine Project.

Contractors

Lock

- subscription is required.

Deposit type

  • Carlin-type
  • Sediment-hosted

Summary:

The Property is located on the eastern flank of the Osgood Mountains within the Basin and Range tectonic province of northern Nevada. The Granite Creek Mine occurs within a northeast-trending structural corridor known as the Getchell gold trend. Gold mineralization at the Property is described as a Carlin-type, sedimentary-rock hosted system.

The Property geology comprises a sequence of Cambrian to Ordovician sedimentary rocks that form part of the Osgood Mountain Terrane and the Osgood Mountains. Much of the Property comprises shales, hornfels sedimentary rocks and limestone interbeds of the Preble Formation, and an overlying (or juxtaposed), alternating sequence of limestone, shale, and dolomite with tuffaceous shale and intraformational conglomerates belonging to the Comus Formation. The Preble and Comus Formations have been folded into a broad north-plunging anticline and have been intruded by large Cretaceous granodiorite stocks, resulting in irregular contact metamorphism.

Gold mineralization at the Property is strongly structurally controlled, occurring at favorable sites within a fault network occurring around the eastern edge of the Osgood granodiorite and predominantly within Comus Formation host rocks. Mineralization is commonly associated with the decarbonatization of carbonate rocks and the introduction of silica, fine grained pyrite, arsenian pyrite, and remobilized carbon. Continuity of mineralization is highly variable, ranging from 40 to 4,500 feet (12 to 1,372 meters) in strike extent, 250 to 1,800 feet (76 to 550 meters) in down-dip extent and 5 to 400 feet (1.5 to 122 meters) in thickness. The underground mineralization has a variable thickness between 5 and 30 feet (1.5 and 9 meters).

Oxidation reaches depths of up to 1,800 feet (550 meters) within shear zones. Oxide mineralization includes pervasive limonite, hematite, along with other iron and arsenic oxides. Historical production from the open pits was focused on the oxidized material. Underground mineralization displays pervasive argillization and decarbonatization of host lithologies, along with the formation of dissolution collapse breccias and intense shearing. Where the alteration is strongest, the altered zones consist of punky, spongy decarbonatized limestone in an argillically altered fine-grained, carbon-rich matrix (Gustavson, 2012). Silicification is minor and occurs as a broad overprint on the zone. Historical underground production included both sulfide and oxide material.

Reserves

Lock

- subscription is required.

Mining Methods

Lock

- subscription is required.

Comminution

Crushers and Mills

Lock

- subscription is required.

Processing

Lock

- subscription is required.

Production

CommodityUnitsLOM
Gold oz 1,245,900
All production numbers are expressed as metal in doré.

Operational metrics

Metrics
Daily ore mining rate  ....  Subscribe
Stripping / waste ratio  ....  Subscribe
Waste tonnes, LOM  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
Total tonnes mined, LOM  ....  Subscribe
* According to 2021 study.

Production Costs

CommodityUnitsAverage
Cash costs Gold USD  ....  Subscribe
All-in sustaining costs (AISC) Gold USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2021 study / presentation.

Operating Costs

Currency2021
Combined mining costs ($/t mined) USD 2.06 *  
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
* According to 2021 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Closure costs $M USD  ......  Subscribe
Total CapEx $M USD  ......  Subscribe
OP/UG OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 252.6
G&A costs $M USD 41.8
Total OpEx $M USD  ......  Subscribe
Mining Taxes $M USD  ......  Subscribe
Income Taxes $M USD  ......  Subscribe
Royalty payments $M USD  ......  Subscribe
Gross revenue (LOM) $M USD  ......  Subscribe
Net revenue (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax NPV @ 5% $M USD  ......  Subscribe
After-tax NPV @ 7% $M USD  ......  Subscribe
After-tax IRR, %  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment

Lock

- subscription is required.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required May 4, 2021
....................... Subscription required ....................... Subscription required Subscription required May 4, 2021
....................... Subscription required ....................... Subscription required Subscription required Apr 29, 2024
....................... Subscription required ....................... Subscription required Subscription required Apr 29, 2024

Total WorkforceYear
...... Subscription required 2021

Aerial view:

Lock

- subscription is required.