Projects

Prescott
Base Metals
Project

Overview

The Prescott Project consists of 52 licences covering 624 km2 that are predominantly located on Prince of Wales and Somerset Island and are interpreted to host an anticlinal repetition of the same geological formation hosting American West Metals Limited’s (ASX:AW1) Storm Copper Project (Figure 1). The Storm Copper Project is 100km east of the Prescott Project and hosts an Indicated & Inferred resource of 17.5 Mt @ 1.2% Cu and 3.4g/t Ag for 205kt of contained copper1. The Prescott Project also includes a significant land package which is directly along strike from the Storm Copper Project, these licences total ~130 km2.

Exploration at the Prescott Project will be principally targeting Sediment Hosted copper deposits, as well as Mississippi Valley-type (Zn-Pb) deposits. Sediment-hosted copper deposits are a globally significant source of copper, forming one of the two main types of copper deposits, the other being porphyry copper deposits. These types of systems present significant opportunity for a material mineral discovery.

The maiden geophysical campaign at the Prescott Base Metals Project commenced in late May 2024, and consists of both an Airborne Gravity Gradiometry (AGG) and Magnetic survey across the entire project area utilising a fixed-wing aircraft. AGG serves to provide a higher resolution than traditional gravity surveys and will be processed into a detailed 3D inversion to identify density anomalies.

Gravity is the preferred geophysical exploration method for this style of mineralisation and has a proven track record in the Resolute region. A previous gravity survey inversion served to positively identify copper mineralisation associated with the Storm deposit, and a gravity survey was also used to discover the Polaris Zn-Pb mine. AGG surveys offer advantages over electromagnetic (EM) surveys, as they are cheaper, quicker, and capable of detecting non-conductive ore minerals.

Figure 1: Interpreted anticlinal repetition of the same geological sequence hosting American West Metals, Storm Copper Project.

Location

The Prescott project is located in the Peel Sound area of the Polaris mineral district of Nunavut, Canada. The 624 km2 land holding lies across Somerset Island, Prince of Wales Island, Cornwallis Island, and some smaller islands within the Peel Sound area. The 100% owned belt-scale project spans a total strike length of over 244 km and is situated approximately 130 km south of Resolute Bay, a regional logistics and support hub located on the Northwest Passage. The region is familiar with large scale mining operations, having previously supported the world class Nanisivik and Polaris zinc-lead mines, and more recently exploration activities with the advancement of the American West Metals (ASX:AW1) Storm Copper project.

Located
adjacent to coast

Access to designated sealift route

Historical mining district with established logistics network and supportive local government

Year-round mining, with reliable shipping window

Figure 2: Location of the Prescott Project and surrounding settlements.

Regional Geology & Copper Mineralisation

The regional geology is dominated by an underlying Archean gneissic basement, overlaid by carbonate sediments such as dolostone, limestone and sandstone. The Caledonian orogeny, during the Silurian to early Devonian periods, resulted in east-west compression which formed the Boothia uplift, which is a 125km wide and 1000km long north-south trending exposure of Archaean basement, situated in between Prince of Wales Island and Somerset Island, and extending north in between Bathurst Island and Cornwallis Island to Devon Island. Later, north-south compression from the Ellesmerian orogeny caused earlier faults to reactivate and formed new strike-slip and normal faults, one of which the Storm deposit is situated on. This north-south compression event drove the migration of metal-rich fluids along fault structures, which resulted in the deposition of copper, silver, zinc, and lead in favourable stratigraphic horizons, such as the Allen Bay Formation.

The Boothia uplift hosts several important metal deposits in sedimentary carbonate rocks from the Proterozoic era. Notable among these are the historic Polaris zinc-lead mine on Little Cornwallis Island, and the Seal zinc and Storm copper deposits on Somerset Island. The Storm Copper deposit is a joint venture between American West Metals (80%) and Aston Bay Holdings (20%) and is situated on the eastern side of the Boothia uplift on Somerset Island. Geologically, the Storm Copper deposit consists of high-grade structurally-controlled feeder structures, and large, stratiform replacement-style copper mineralisation hosted in the Allen Bay formation. The Allen Bay Formation is a porous carbonate unit which provides a reducing environment for the precipitation of copper sulphides.

The Storm Copper Project currently hosts a JORC (2012) resource of 17.5 Mt at 1.2% Cu and 3.4 g/t Ag, for a total of 205 kt Cu and 1.9 Moz Ag2. The main minerals found in the deposit are chalcocite, bornite, and chalcopyrite, with copper mineralisation being hosted in the upper 80 m of the Allen Bay formation.

The Polaris and Seal deposits are Mississippi Valley-Type deposits, with very high zinc concentrations of 13.4% and 10.2% Zn, respectively3. The presence of base metals in economic concentrations over hundreds of kilometres of apparent strike suggests a regional scale base metal district with world-class potential.

Figure 3: Prescott Project licence area and surrounding landholders.

Mineralisation Model

The geology of the Prescott Project area is interpreted to contain these essential elements required to host either a sedimentary-hosted copper deposit or a Mississippi Valley-type (Zn-Pb) deposit, due to its geological similarities in terms of host rocks and structural architecture to the opposite side of the anticline, where the Storm and Seal deposits are located (Figure 1).

Planned exploration activities across the Prescott Project area will be principally targeting sedimentary-hosted copper, similar to Eastern Europe’s Kupferschiefer deposits and Central Africa’s Copperbelt deposits like Kipushi in Zambia and the DRC. Typically, sedimentary-hosted copper deposits form when oxidised copper-bearing brines are mobilised along permeable lithologies or faults, and then encounter a reducing environment such as carbonaceous shales or carbonates. This interaction causes the copper-bearing fluids to precipitate copper sulphides.

Figure 4: Overview of sedimentary copper deposit model for the Prescott Project (adapted from Aston Bay Holdings, TSX:BAY 28/09/2022)

The storm deposit hosts two styles of mineralisation:

  1. High grade, fault-hosted breccia feeder structures that transported the copper-bearing fluid from its source
  2. Large, flat, stratiform sediment-hosted copper located in the upper 80 metres of the Allen Bay formation.

During the Ellesmerian Orogeny, north-south compression forced meteoric water through the Aston Formation’s red beds, scavenging copper. These oxidised, copper-rich fluids are then interpreted to have moved southward through permeable lithologies, rising to the surface via secondary normal and strike-slip faults, and reactivated thrust faults. These fluids then encountered the porous carbonate units of the Allen Bay Formation, where the presence of the overlying impermeable Cape Storm Formation helped focus these oxidised copper-rich fluids to be reduced within fractures and porous zones of the Allen Bay formation. This process led to the formation of high-grade fracture fill and lower-grade replacement style copper mineralisation, as observed in the Storm Deposit (Figure 4). This geological model will be employed across the Project area to guide future targeting of other prospective locations which exhibit similar structural and lithological characteristics.

Footnotes

  1. Refer to AW1’S ASX Announcement on 30/01/2024 – Maiden JORC MRE for Storm. There is no certainty that further work by the Company will lead to achieving the same size, shape, grade, or form of the comparison resource. The Company’s project is in a different stage of development and that further exploration needs to be undertaken to further prove or disprove any comparison. ↩︎
  2. Refer to AW1’S ASX Announcement on 30/01/2024 – Maiden JORC MRE for Storm. There is no certainty that further work by the Company will lead to achieving the same size, shape, grade, or form of the comparison resource. The Company’s project is in a different stage of development and that further exploration needs to be undertaken to further prove or disprove any comparison. ↩︎
  3. Polaris historical production of 20.1 Mt at 13.4% Zn and 3.6% Pb (Reid, S., Dewing, K. and Sharp, R. (2013) ‘Polaris as a guide to northern exploration: Ore textures, Paragenesis and the origin of the carbonate-hosted Polaris Zn–PB Mine, Nunavut, Canada’, Ore Geology Reviews, 51.); Seal inferred mineral resource of 1.0 Mt at 10.24% Zn and 46.6 g/t Ag (P&E Mining Consultants Inc., 2017. NI-43-101 and 43-101F1 Technical Report titled ‘Initial Mineral Resource Estimate and Technical Report for the Seal Zinc Deposit, Aston Bay Property, Somerset Island, Nunavut)’. ↩︎