Follow Us! Like Our Page!

Seabridge Gold Reports Updated Mineral Resource Estimates for Mitchell and East Mitchell Deposits

Press Release

Toronto, Ontario–(April 14, 2022) – Seabridge Gold (TSX: SEA) (NYSE: SA) reported today updated mineral resource estimates for its Mitchell and East Mitchell (formerly Snowfield) deposits which incorporate drilling completed in 2021. These resource estimates will be used in an updated KSM Preliminary Feasibility Study (PFS) expected in June 2022 that will, for the first time, incorporate the East Mitchell deposit into KSM’s mine plans. The Mitchell and East Mitchell are two of five deposits in Seabridge’s 100%-owned, district-sized KSM project in the Golden Triangle region of northwestern British Columbia, Canada. The East Mitchell deposit was acquired by Seabridge in 2020 from Pretium Resources.

The updated mineral resource estimates for Mitchell and East Mitchell are as follows:

Undiluted Open Pit Constrained Mineral Resources as of March 31, 2022

Deposit Resource
Average Grades Contained Metal
Mitchell Measured 691.7 0.68 0.19 3.3 52 15.1 2,876 72.8 79
Indicated 1,667.0 0.48 0.14 2.8 66 25.9 5,120 149.2 241
Inferred 1,282.6 0.29 0.14 2.4 47 11.8 3,832 102.2 133
East Mitchell Measured 1,012.8 0.65 0.11 1.8 89 21.1 2,514 59.2 198
Indicated 746.2 0.42 0.08 1.7 79 10.1 1,390 41.8 130
Inferred 281.1 0.37 0.07 2.3 61 3.4 403 21.1 38
Totals Measured plus Indicated 4,117.7 0.54 0.13 2.4 71 72.2 11,900 323.0 648
Inferred 1,563.7 0.30 0.13 2.5 50 15.2 4,235 123.3 171


  1. The Mineral Resource estimate has been prepared by Henry Kim P.Geo., an independent Qualified Person.
  2. Resources are reported using the 2014 CIM Definition Standards and were estimated in accordance with the CIM 2019 Best Practices Guidelines.
  3. Mineral Resources are reported inclusive of Mineral Reserves.
  4. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
  5. Net Smelter Return (NSR) Cut offs are $10.75/t for Mitchell and $11.20/t for East Mitchell using the following assumptions: metal prices of US$1300/oz Au, US$3.00/lb Cu, US$20/oz Ag, and US$ 9.7/lb Mo at a currency exchange rate of 0.79 US$ per C$; Copper concentrate terms are 96% payable Cu; 97.8% payable Au; 90% payable Ag. Offsite costs (smelting, refining, transport, and insurance) are $281 per tonne of concentrate; doré terms are $2/oz Au offsite costs (refining, transport and insurance), 99.8% Au payable, and 90% Ag payable; metallurgical recovery projections vary depending on metallurgical domain and metal grades and are based on metallurgical test work.
  6. The Mineral Resource has been constrained by a “reasonable prospects of eventual economic extraction” pit using the following assumptions: metal prices of US$1820/oz Au, US$4.20/lb Cu, US$28/oz Ag, and US$ 13.5/lb Mo at a currency exchange rate of 0.83 US$ per C$; Pit slopes range between 32-51 degrees in the Mitchell area and 25-43 degrees in the East Mitchell area; $2.20/t mining costs; $10.75/t process + G&A costs for Mitchell; $11.20/t process + G&A costs for East Mitchell; offsite terms and metallurgical recoveries are the same as Note 5.
  7. “Moly” = “Molybdenum”
  8. Numbers may not add due to rounding.
  9. Unless noted, dollars reported herein are Canadian dollars.

Seabridge Chairman and CEO Rudi Fronk noted that, “We are very eager to see how this new resource estimate folds into our revised PFS. We expect the combination of East Mitchell and Mitchell to create a single very large open pit mining opportunity with improved economic projections including a likely increase in proven and probable gold reserves, better grades in the early years of production and deferral of the need to pay for capital intensive underground block-cave development. These expected gains, along with higher metal prices, should help offset the impact of inflation on materials and labor costs in the updated PFS.”

Fronk also noted that, “With these resource additions, we have once again met our annual corporate objective of increasing our gold ownership on a per share basis. Since our last published resource estimate in December 2020, we have added 12.0 million ounces of gold in the measured and indicated categories, reduced inferred gold resources by about 0.2 million ounces and increased shares outstanding by approximately 5.6 million for new financings. Enhancing shareholder ownership of gold resources remains a governing objective for our Company and we were able to continue to achieve it over the past 15 months.”

Gold, copper, silver and molybdenum grades in the Mitchell and East Mitchell resource were estimated by Wood PLC (“Wood”) using ordinary kriging methods. Geological domains for lithology, structure and alteration were created in 3-dimensions to constrain models independently derived for gold, copper, silver, and molybdenum. An ordinary kriging estimation with 7.5 meter assay composites and outlier restrictions was used to select eligible composites for block grade estimation. Orientation of search ellipses was developed from updated variography studies and designed to honor structural orientations of the deposits.

Drill hole data from Mitchell and East Mitchell were evaluated and consolidated into a single dataset. The Mitchell mineral resource database is 96% from Seabridge drilling using consistent and robust procedures for drilling, collar surveying, downhole surveying, sampling, assaying and assay quality control. East Mitchell drilling was checked in detail by Seabridge and Wood prior to incorporation in the dataset including a check sampling program carried out on 76 drill core intervals from 14 legacy drillholes and multiple assay procedures completed on confirmation holes drilled in 2021. This work assures that the East Mitchell and Mitchell datasets are consistent and reliable.

Validation of the estimation models was carried out separately for gold, copper, silver and molybdenum using a combination of:

  • visual inspection of estimates and assay composites,
  • comparison of estimated grades and nearest neighbor validation model grades by domain,
  • checks on the impacts of outlier restrictions on metal reduction by domain
  • construction and inspection of swath plots to check grade trends in estimated block grades
  • reconciliation to previous resource models

Bench plans of gold, silver copper and molybdenum were reviewed individually by plotting assay composite grades and estimated block grades. During inspections of bench plans areas of block grades were identified as potentially over-projections of high-grade composites and outlier restrictions were refined. Additionally, the influence of estimation domain boundaries in controlling grade trends was confirmed. Interpolated block grades match local composites well and the trends in block grades between drillholes are reasonable.

Net smelter return values (“NSR” values) were calculated by Moose Mountain Technical Services using metal recovery projection formulae developed by Tetra Tech from metallurgical test work on the deposits. This NSR value, stated in terms of Canadian dollars, reflects metal prices of US$3.00 per pound of copper, US$1300 per ounce of gold, US$20 per ounce of silver, US$9.70 per pound of molybdenum, a US$/C$ currency exchange rate of 0.79, estimated metal recoveries and offsite transportation, smelting, and refining charges. Resources are tabulated inside a hypothetical constraining pit shapes using an NSR cut-off value of $10.75/t for the Mitchell deposit and $11.20/t for the East Mitchell deposit.

Resource estimates included herein were prepared by Wood under the supervision of Henry Kim, P.Geo., who is independent of Seabridge, and a Qualified Person as defined by National Instrument 43-101. Mr. Kim has reviewed and approved this news release.

An ongoing and rigorous quality control/quality assurance protocol is employed in all Seabridge drilling campaigns. This program includes blank and reference standards; in addition, all copper assays exceeding 0.25% Cu are re-analyzed using ore grade analytical techniques. Random cross-check analyses are conducted at a second external laboratory on at least 10% of the drill samples. Samples are assayed at ISO and ASTM certified laboratories in Vancouver, B.C., using fire assay atomic adsorption methods for gold and ICP methods for other elements.

Seabridge holds a 100% interest in several North American gold projects. Seabridge’s assets include the KSM and Iskut projects located near Stewart, British Columbia, Canada, the Courageous Lake project located in Canada’s Northwest Territories, the Snowstorm project in the Getchell Gold Belt of Northern Nevada and the 3 Aces project set in the Yukon Territory. For a full breakdown of Seabridge’s mineral reserves and mineral resources by category please visit the Company’s website at

“Rudi Fronk”
Chairman and C.E.O.

For further information please contact:
Rudi P. Fronk, Chairman and C.E.O.
Tel: (416) 367-9292 • Fax: (416) 367-2711
Email: [email protected]


 122 total views,  2 views today

NationTalk Partners & Sponsors Learn More