2022 Mineral Resource Estimate & Preliminary Economic Assessment

In June 2022 Benchmark released a Mineral Resource Estimate (MRE) for the Lawyers Gold-Silver Project and subsequently, a Preliminary Economic Assessment (PEA) later that year.

With the recent completion of the Benchmark and Thesis merger, the company sees many opportunities to add additional ounces to a future MRE and to materially improve the economics of an updated PEA. As such, both the MRE and PEA presented below are very much base-case scenarios. See our plans for 2023/24 for a detailed update on how we plan to achieve these goals.

Preliminary Economic Assessment

In the fall of 2022, a Preliminary Economic Assessment was conducted to explore the economics and resource potential at the Lawyers project. The PEA defined a 12-year mine life for an open pit operation focused on bulk-tonnage material. None of the identified underground mineral resources were utilized in the mining scenario provided.

2022 PEA Highlights (Open pit Only):

  • Pre-tax NPV 5% of C$939M, with an IRR 31.4%, and 2-year payback
  • Pre-tax Net Operating Income of C$2,157M
  • Base case metal price parameters of US$1,735 per ounce of gold and US$21.75 per ounce of silver
  • After-tax NPV5% of C$589M, IRR 24.1%, and 2.8-year payback

Capital Development

  • Initial capital of C$484M (including C$72.8M in contingency)
  • Life of Mine capital of C$626M
  • Strong 1.9:1 Pre-tax NPV5% to Initial Capex ratio
  • Minimal pre-strip limited to TSF starter dam construction

Low All-In Sustaining Costs (AISC)

  • US$ 786/Au oz (net of by-products)1

Long Mine Life with Expansion Opportunity

  • Total resource production of 46.7 M tonnes over 12-year mine life
  • Average annual Au average production of 136 KozAu/year and 2.124 Moz Ag/year for a total of 163 Koz AuEq (at 80:1 Ag:Au ratio)2
  • LOM production 1.95M payable AuEq ounces
  • Average AuEq Head Grade of 1.41 g/t
  • Average gold recovery of 92.4%

Mineral Resource Estimate

In June 2022 the Company released a Mineral Resource Estimate (MRE) for the Lawyers Gold-Silver Project that includes recently delineated bulk-tonnage material and potentially mineable higher grade underground material. Drilling in 2021 and winter 2022 defined an indicated mineral resource of 3.14 million ounces (Moz), with approximately 95% of the estimated, open pit-able resource classified as Measured & Indicated (see Table 1 for details). The Mineral Resource is amenable to both open pit and underground mining methods and shows excellent continuity and consistency in mineable gold and silver grades. Zones included within the PEA remain open and are being tested as part of the 50,000 metre drill program in 2023.

Table 1. Lawyers Expanded Mineral Resource Estimate (1-9)

Notes:

1. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

2. The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.

3. The Inferred Mineral Resource in this estimate has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of the Inferred Mineral Resource could potentially be upgraded to an Indicated Mineral Resource with continued exploration.

4. The Mineral Resources were estimated in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM), Standards on Mineral Resources and Reserves, Definitions (2014) and Best Practices Guidelines (2019) prepared by the CIM Standing Committee on Reserve Definitions and adopted by the CIM Council.

5. Historical mined areas were removed from the block modelled resources.

6. Metal prices used were US$1,750/oz Au and US$20/oz Ag and 0.78 US$ CDN$ FX with process recoveries of 90% Au and 83% Ag. A C$14.50/t process cost and C$5/t G&A cost were used. The Au:Ag ratio was 80:1 for the purposes of calculating AuEq.

7. The constraining pit optimization parameters were C$3.15/t mineralized and waste material mining cost and 50° overall pit slopes with a 0.40 g/t AuEq cut-off.

8. The Out-of-Pit Mineral Resource blocks were quantified as those blocks above the 1.5 g/t AuEq cut-off, below or outside the constraining pit shell and within the constraining mineralization wireframes. Out-of-Pit Mineral Resources selected exhibited continuity and reasonable potential for extraction by the long hole underground mining method. Differences may occur in totals dues to rounding.

9. Source: JDS Energy and Mining Inc. and the PEA (2022)

PEA – Identified Opportunities – Underground Mining Inclusion

The PEA for the Lawyers Gold-Silver Project has pinpointed several pivotal opportunities for project optimization. Central to these opportunities is the inclusion of underground mining methods. The assessment indicates that “there is a strong opportunity to enhance the Base Case economics with supplemental feed from underground operations.”

Specifically:

  • Adjacent to and beneath the Cliff Creek Pit lies a significant potential for underground operations. The mineralized zones in this area are sub-vertical and have a thickness ranging from 4 to 15 meters, making them suitable for underground mining. (See Figure 26-1)
  • The PEA outlines three potential scenarios for integrating underground mining:
    1. Merging underground with open pit operations, which could elevate the grade of the mill feed and prolong the project’s lifespan.
    2. Initiating underground operations post the completion of open pit activities, offering a further extension to the project’s operational life.
    3. Evaluating the cost-effectiveness of underground mining for the deepest pit phases, potentially prioritizing it over surface mining.
  • It’s also emphasized that future analyses should be comprehensive, taking into account all deposits and not just focusing on the Cliff Creek area.

Quality Assurance and Control

Results from samples were analyzed at ALS Global Laboratories (Geochemistry Division) in Vancouver, Canada (an ISO/IEC 17025:2017 accredited facility). The sampling program was undertaken by Company personnel under the direction of Rob L’Heureux, P.Geol., and a secure chain of custody was maintained in transporting and storing of all samples. Gold was assayed using a fire assay with atomic emission spectrometry and gravimetric finish when required (+10 g/t Au). Analysis by four acid digestion with 48 element ICP-MS analysis was conducted on all samples with silver and base metal over- limits being re-analyzed by atomic absorption or emission spectrometry. Rock chip samples from outcrop/bedrock are selective by nature and may not be representative of the mineralization hosted on the project.


Michael Dufresne, M.Sc., P.Geol., P.Geo., serves as a Technical Advisor and is the Qualified Person, as defined by National Instrument 43-101, responsible for reviewing and approving the technical content of all materials publicly disclosed by the Company, including the contents of this website.

Figure 1-Mine site plan for the Lawyers Property

Figure 2-High-grade mineralization continues 4-15 metres beyond the pits and remains open at depth, leaving significant expansion potential for the resource by underground mining.

Figure 4-2022 Mineral Resource Estimate displaying Cliff Creek, Dukes’s Ridge, and AGB Zones and Starter pit locations. All resource zones remain open at depth and near surface.

Exploration in the Toodoggone Mining District began in the 1960s by prospectors drawn to the area by prominent rusty colored ridges and waterways. By the 1980s, numerous precious metal occurrences, prospects, and deposits were defined and discovered including porphyry gold-copper mineralization at Kemess, and epithermal style mineralization at Ranch and Lawyers.

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