Stillwater West PGE-Ni-Cu (Montana)

HIGHLIGHTS:

  • 100%-owned, large, brownfields project in Montana’s Stillwater District; one of the world’s largest and highest-grade PGE-Ni-Cu regions
  • Inaugural 2021 mineral resource estimate total 2.4 million ounces palladium, platinum, rhodium, and gold (“4E”) plus 1.1 billion pounds of nickel, copper and cobalt in a constrained model totaling 157 million tonnes at an average grade of 0.45% total nickel equivalent (“NiEq”) (equal to 1.20 g/t palladium equivalent, or “PdEq”) using a 0.20% NiEq cut-off grade1
  • Assays pending from 2021 drill program with results expected to form basis of mineral resource update
  • Adjacent to high-grade Sibanye-Stillwater’s PGE Mines¹ with over 14Moz past Pd+Pt production2
  • The Stillwater District has a rich mining history for PGEs, Ni, Cu, Cr, and other commodities
  • The project features an extensive database –– including almost 12,000 m of core –– to which Group Ten is applying modern geological models developed in South Africa at Ivanhoe’s Platreef and Anglo American’s Mogalakwena mines
  • Compilation and analysis by Group Ten shows the potential for much larger mineralized systems than have been previously recognized
  • Existing road access and power infrastructure with three operating mines

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OVERVIEW

The Stillwater West PGE-Ni-Cu Project consists of 14 multi-kilometer-scale exploration target areas along a 32 km strike length adjoining and adjacent to Sibanye-Stillwater’s high-grade Stillwater (Stillwater, East Boulder, and Blitz) mines in the Stillwater Igneous Complex of Montana, USA. Located in one of the top regions in the world for PGE-Ni-Cu mineralization, the producing J-M Reef deposits operated by Sibanye-Stillwater is the highest-grade major PGE project in the world and the largest outside South Africa and Russia. In June 2017, one month after South African producer Sibanye announced the completed takeover of Stillwater Mining company for USD 2.2 billion, Group Ten Metals announced the closure of the Stillwater West project acquisition deal, which positions the Company as the second largest landholder in the district. In addition to the land package, the Stillwater West acquisition included an extensive historic database of soil and rock geochemistry, geophysical surveys, geologic mapping, and historic drilling with nearly 12,000 metres of preserved core.

The Stillwater Complex is a 2.7 billion-year-old layered intrusive mafic-ultramafic complex with geology similar to South Africa’s Bushveld Complex. Mining in the Stillwater District currently occurs along the J-M Reef, a PGE-enriched sulphide horizon that shares many similarities with the highly-prolific Merensky and UG2 Reefs in the Bushveld Complex, particularly very high PGE grades along narrow seams. In addition to these narrower “reef-type” deposits, the Bushveld also hosts much larger-scale disseminated and high-sulphide PGE-nickel-copper-type deposits, including Anglo American’s world-leading Mogalakwena Mine and Ivanhoe’s developing Platreef Mine. Similarly, the lower part of the Stillwater Complex, which hosts the majority of Group Ten’s 54 km² holdings, also shows the potential for these broadly-disseminated deposits that can range well beyond 100 metres in thickness. 

In October 2021, Group Ten announced its inaugural mineral resource estimate on the Stillwater West project. Prepared by SGS Geological Services, the Inferred mineral resource consists of a constrained model totaling 157 million tonnes at an average grade of 0.45% total nickel equivalent (“NiEq”) (1.20 g/t palladium equivalent, or “PdEq”) using a 0.20% NiEq cut-off grade for total contained metal including 1.1 billion pounds of nickel, copper and cobalt with 2.4 million ounces palladium, platinum, rhodium, and gold (“4E”)1. The estimate incorporates starter deposits at five target areas within the central area of the project which covers just 8.7 kilometers (“km”) of the overall 32km strike length. The Company’s 2021 drill campaign was designed based on the demonstrated strong correlation of drill-defined mineralization with both geophysical and geochemical anomalies with the goal of resource expansion and enhancement.

CIM (2014) definitions were followed for Mineral Resources Reporting. The constrained Mineral Resources are reported at a base case cut-off grade of 0.20% NiEq. Cut-off grades and metal equivalents are based on metal prices of $7.00/lb Ni, $3.50/lb Cu, $20.00/lb Co, $900/oz Pt, $1,800/oz Pd and $1,600/oz Au, with assumed metal recoveries of 80% for Ni, 85% for copper, 80% for Co, Pt, Pd and Au, a mining cost of US$2.20/t rock, and processing and G&A cost of US$12.75/t mineralized material. Rhodium modeled but not included in equivalency calculations. All figures are rounded to reflect the relative accuracy of the estimate.

The current Mineral Resources are not Mineral Reserves as they do not have demonstrated economic viability. The quantity and grade of reported Inferred Resources in this Mineral Resource Estimate are uncertain in nature and there has been insufficient exploration to define these Inferred Resources as Indicated or Measured. However, based on the current knowledge of the deposits, it is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.

A total of 14 exploration target areas ranging from 3 to 8 km in length and defined by major high-level electro-magnetic conductors with broad coincident soil geochemical anomalies have been identified on the Stillwater West property. Each of these are further divided into eight ‘Platreef-style’ bulk tonnage PGE-Ni-Cu sulphide exploration target areas and six ‘Reef-type’ higher-grade PGE areas. While Group Ten’s Stillwater West property hosts both styles (the “reef-type” Picket Pin in the upper portion of the Complex and the larger “Platreef-type” deposit located in the lower portion), the Company has prioritized exploration of the lower Stillwater Complex where work to date demonstrates strong potential for very large, world-class mineralized systems. Each of the major conductor targets on the main claim is as large as Ivanhoe’s Platreef deposit and drilling data from the 1960s, 1970s, and 2000s confirms the presence of significant intervals of platinum group elements (PGE) and cobalt with nickel and copper sulphides associated with at least six (6) of the 15 identified geophysical exploration target areas. 

The eight ‘Platreef-style’ PGE-Ni-Cu exploration target areas occur within the ultramafic and basal part of the Stillwater Complex and are highlighted by strong electro-magnetic conductive signatures that are characteristic of large bodies of massive to extensively disseminated sulphides. These geophysical exploration targets have overlapping highly elevated palladium, platinum, gold, nickel, copper, and chromium values in soils and rock sampling. Individual target areas have from a few drill holes to as many as 30 wide-spaced holes that have intercepted significant levels of platinum, palladium, and gold along with nickel, copper, cobalt, rhodium, vanadium, and chromium.

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PRIORITIES FOR 2021:

  • Convert mineralized zones to formal resources (announced October 21)
  • Expand known mineralization into untested areas
  • Identify and prioritize new targets

UPCOMING NEWS:

  • Inaugural mineral resource estimate (announced October 21)
  • Initial assays from 2021 drill program
  • Updates regarding secondary projects
  • Potential mineral resource estimate update (2022)

 

¹CIM (2014) definitions were followed for Mineral Resources Reporting. The constrained Mineral Resources are reported at a base case cut-off grade of 0.20% NiEq. Cut-off grades and metal equivalents are based on metal prices of $7.00/lb Ni, $3.50/lb Cu, $20.00/lb Co, $900/oz Pt, $1,800/oz Pd and $1,600/oz Au, with assumed metal recoveries of 80% for Ni, 85% for copper, 80% for Co, Pt, Pd and Au, a mining cost of US$2.20/t rock, and processing and G&A cost of US$12.75/t mineralized material. Rhodium modeled but not included in equivalency calculations. All figures are rounded to reflect the relative accuracy of the estimate.

The current Mineral Resources are not Mineral Reserves as they do not have demonstrated economic viability. The quantity and grade of reported Inferred Resources in this Mineral Resource Estimate are uncertain in nature and there has been insufficient exploration to define these Inferred Resources as Indicated or Measured. However, based on the current knowledge of the deposits, it is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.
 

2References to adjoining properties are for illustrative purposes only and are not necessarily indicative of the exploration potential, extent or nature of mineralization or potential future results of the Company’s projects.

J-M Reef Deposit (Sibanye-Stillwater)

Reserves:    25.6 Moz P&P at 13.4 g/t Pd and 3.8 g/t Pt

Resources:  34.1 Moz M&I at 12.8 g/t Pd and 3.6 g/t Pt

                     45.9 Moz Inf at 12.75 g/t Pd and 3.6 g/t Pt.

Mineral Resources based on Sibanye-Stillwater’s 2018 Mineral Resources and Mineral Reserves Report. These resource and reserve estimates were prepared by Sibanye-Stillwater based on the South African Code for the Reporting of Mineral Asset Valuation and the South African Code for the Reporting of Mineral Asset Valuation, which differ from the requirements of NI 43-101 and SEC Industry Guide 7. The Company does not have access to such project or underlying information and has not independently verified any of the scientific, technical or exploration information related to such third-party project.

2Based on publicly disclosed production statistics of Sibanye-Stillwater including most recent CPR.

 

 

 

 

 

 

 

*References

Mineralization identified on adjacent properties does not necessarily indicate that mineralization will be identified on Group Ten Metals projects.

Report on Montana Platinum Group Metal Mineral Assets of Sibanye-Stillwater, November 2017, Measured and Indicated Resources of 57.2 million tonnes grading 17.0 g/t Pt+Pd containing 31.3 million ounces and 92.5 million tonnes grading 16.6 g/t containing 49.4 million ounces.

Public production records from Stillwater Mining Company from 1992 to present.

Magmatic Ore Deposits in Layered Intrusions—Descriptive Model for Reef-Type PGE and Contact-Type Cu-Ni-PGE Deposits, Michael Zientek, USGS Open-File Report 201

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