IAMGOLD Corporation (TSX: IMG) (NYSE: IAG) is pleased to announce results from its 2021 exploration infill drilling program completed at the Diakha deposit on its wholly owned Diakha-Siribaya Gold project located in western Mali along the borders with Senegal and Guinea.

Highlights include:

Diamond Drill Holes (refer to Table 1 below)

• 12 meters at 9.32 grams per tonne gold in drill hole SRD21-284 from 284 m including
  • 3 m at 27.15 g/t Au from 284 m
• 13 m at 11.20 g/t Au in drill hole SRD21-303 from 277 m including
  • 2 m at 67.98 g/t Au from 279 m
• 10 m at 11.70 g/t Au in drill hole SRD21-305 from 164 m including
  • 4 m at 27.63 g/t Au from 169 m
• 17 m at 2.17 g/t Au in drill hole SRD21-300 from 177 m, followed by a separate interval of:
  • 20 m at 5.47 g/t Au from 269 m including
  • 7 m at 11.74 g/t Au from 282 m
• 20 m at 5.40 g/t Au in drill hole SRD21-308 from 108 m including
  • 1 m at 69.34 g/t Au from 114 m
• 13 m at 4.12 g/t Au in drill hole SRD21-307 from 224 m including
  • 1 m at 17.40 g/t Au from 225 m and
  • 2 m at 13.40 g/t Au from 233 m
• 15 m at 3.91 g/t Au in drill hole SRD21-311 from 242 m including
  • 3 m at 13.06 g/t Au from 246 m and
  • 1 m at 11.40 g/t Au from 251 m

Reverse Circulation (“RC”) Drill Holes (refer to Table 2 below)

• 16 m at 14.00 g/t Au in drill hole SRD21-891 from 89 m including
  • 3 m at 41.95 g/t Au from 99 m
• 20 m at 1.97 g/t Au in drill hole SRD21-883 from 43 m, including
  • 1 m at 21.89 g/t Au from 48 m, followed by a separate interval of:
  • 27 m at 2.12 g/t Au from 75 m including
  • 3 m at 6.52 g/t Au from 76 m and
  • 1m at 21.31 g/t Au from 101 m
• 12 m at 4.19 g/t Au in drill hole SRD21-889 from 108 m including
  • 2 m at 18.84 g/t Au from 117 m
• 32 m at 1.97 g/t Au in drill hole SRD21-907 from 88 m including
  • 1 m at 16.40 g/t Au from 89 m
• 11 m at 4.96 g/t Au in drill hole SRD21-848 from 55 m including
  • 1 m at 39.80 g/t Au from 65 m
• 24 m at 2.23 g/t Au in drill hole SRD21-882 from 43 m including
  • 2 m at 17.01 g/t Au from 54 m

Craig MacDougall, Executive Vice President, Growth for IAMGOLD, stated: “We are very pleased with the results of our 2021 exploration program, which have helped to demonstrate continuity of mineralization between previously completed drill holes and better delineate the distribution and controls on high grade mineralized structures within the known resource.”

“The data from this program will help improve the current deposit model and support the completion of an updated mineral resources estimation as we continue to advance towards our objective of increasing total indicated resources to above 1.5 million ounces.”

In 2021, the Company completed a combined 19,952 meters in 131 diamond and RC drill holes with 22,328 assay samples (including QA/QC samples) submitted for analysis. The main objective of the drilling program was to infill and increase confidence in the current resources estimate for the Diakha deposit.

Diakha-Siribaya Gold Project

The Diakha-Siribaya project is wholly-owned by IAMGOLD and consists of eight contiguous exploration permits which cover a total area of 596.5 square kilometres, located in the Kédougou-Kéniéba inlier of the West African Craton region of western Mali along the borders with Senegal and Guinea.

Gold mineralization is hosted within highly prospective, Birimian-aged metasedimentary, volcanic and intrusive rocks proximal to the Senegal-Mali Shear Zone. At Diakha, the largest deposit discovered to date, gold mineralization occurs within an albitized sandstone unit similar to that hosting IAMGOLD’s Boto Gold deposit located approximately 10 kilometres to the north along strike.

The current mineral resources estimate for the Diakha deposit (on a 100% basis using a $1,500 per ounce gold price) comprises 15.9 million tonnes of indicated resources averaging 1.20 grams of gold per tonne for 615,300 ounces of gold and 18.2 million tonnes of inferred resources averaging 1.62 grams of gold per tonne for 947,500 ounces (see news releases dated January 30, 2019 and February 17, 2021).

Next Steps

The drilling data from the 2021 exploration program is currently being incorporated into a revised deposit model to support the completion of an updated mineral resources estimate targeted for completion in the first half of 2022.

Figure 1 – Diakha-Siribaya – Diakha deposit drill hole surface plan and highlighted 2021 assays

Figure 2 – Diakha-Siribaya – Diakha deposit longitudinal section and highlighted 2021 assay results

Notes:

1. The true widths of intersections are unknown at this time, but are interpreted to approximate the reported downhole lengths.
2. Drillhole intercepts are calculated using a minimum downhole length of two meters, a cut-off grade of 0.5 g/t gold, and may include up to four metres of internal dilution.
3. Assays are reported uncut, but high grade sub-intervals are highlighted.

Notes:

1. The true widths of intersections are unknown at this time, but are interpreted to approximate the reported downhole lengths.
2. Drillhole intercepts are calculated using a minimum downhole length of two meters, a cut-off grade of 0.5 g/t gold, and may include up to four metres of internal dilution.

Assays are reported uncut, but high grade sub-intervals are highlighted

About IAMGOLD

IAMGOLD is a mid-tier gold mining company operating in three regions globally: North America, South America and West Africa. Within these regions the Company is developing high potential mining districts that encompass operating mines and construction, development and exploration projects. The Company’s operating mines include Essakane in Burkina Faso, Rosebel (including Saramacca) in Suriname and Westwood in Canada. A solid base of strategic assets is complemented by the Côté Gold construction project in Canada, the Boto Gold development project in Senegal, as well as greenfield and brownfield exploration projects in various countries located in the Americas and West Africa.

IAMGOLD employs approximately 5,000 people. IAMGOLD is committed to maintaining its culture of accountable mining through high standards of Environmental, Social and Governance practices, including its commitment to Zero Harm®, in every aspect of its business.