Results continue to drive the first ever detailed geological model of the lower Stillwater Igneous Complex. Informed by senior in-house expertise from similar geology in the Bushveld Igneous Complex, the Company's 3D geologic model demonstrated a very high success rate during the 2023 campaign, intersecting the following mineralization style: Platreef-style Ni-PGE-Cu-Co mineralization - The Stillwater West project covers the lower Stillwater Igneous Complex stratigraphy immediately adjacent to Sibanye-Stillwater's mining operations on the J-M Reef deposit, a 40km-long reef deposit that contains the highest palladium-platinum grades in the world, hosted within nickel-copper sulphide. Recognizing the geologic parallels with South Africa's Bushveld Igneous Complex, the Company has successfully defined large-scale deposits in Montana'sStillwater Igneous Complex that are directly analogous to the giant mines of the Platreef. Production on the northern limb of the Bushveld, or Platreef, started in 1993 at Anglo American's Mogalakwena mines and will be joined by Ivanhoe's Platreef mine later this year. Although known primarily as a platinum group element mine, Mogalakwena is one of the largest nickel sulphide mines in the world and is the largest nickel producer in South Africa, in addition to producing a significant amount of copper. Ivanhoe's Platreef mine is projected to become the second largest nickel producer in South Africa. The mines of the Platreef are attractive because they are among the largest and most profitable mines in the world. Their scale and grade allow the application of mechanized bulk mining methods with resulting economies of scale and low operating costs. These deposits also contain significant quantities of nickel, copper, and platinum group metals in a polymetallic combination that is globally very rare. To date, the Company has modeled five deposits of Platreef-style mineralization in the lower Stillwater Igneous Complex, hosting a total of 1.6 billion pounds of nickel, copper and cobalt, and 3.8 million ounces of palladium, platinum, rhodium, and gold, as announced January 2023. Expansion drilling in 2023 confirmed Platreef-style mineralization in the first ever drill tests of an EM geophysical anomaly that forms part of a string of anomalies extending over 12 kilometers along strike associated with sulphide-bearing hornfels and banded iron formation proximal to the Stillwater Igneous Complex footwall contact. Drill core contains significant evidence of assimilation textures and high sulphide contents reminiscent of incorporation of crustal sulphur into the magma from the footwall sediments. Additional drilling is planned to further expand this discovery. N-Series Structures - N-series mineralization consists of north-south trending structures that crosscut the broadly layered nature of the Stillwater Igneous Complex. As announced on December 5, 2023, the N structures contain high-grade nickel sulphide mineralization that was first discovered by the Company in drill holes CM2020-04 and CM2021-05. First reported on March 3, 2021 and later re-interpreted, hole CM2020-04 returned 8.5 meters of 1.11% Ni, 1.10 g/t 4E (Pd+Pt+Au+Rh), 0.19% Cu, and 0.053% Co for 1.50% NiEq. Hole CM2021-05, first reported May 3, 2022, returned 13.2 meters of 2.31% Ni, 1.51 g/t 4E, 0.35% Cu, and 0.115% Co, for 2.85% NiEq. These structures represent an important addition to the Stillwater West project as they appear to upgrade the broader Platreef-style mineralized zones where they crosscut. Modeling has now identified eight N-series structures in the Chrome Mountain area and confirmed the existence of similar N-structures more broadly across Stillwater West. A high-resolution ground magnetic survey early in the 2023 field season enabled a more detailed geologic model, leading directly to the intersection of the N1 and N2 structures in holes CM2023-01 to 05. Assays from holes CM2023-01 to 03 are pending with results expected over the coming weeks. Reef-type PGE-Ni-Cu Mineralization - Stillwater West contains another mineralization style that is common in layered magmatic systems, the narrower but higher-grade Reef-type deposits. Historically, the majority of the world's supply of platinum group elements ("PGE") has been sourced from mines of this type, and the close proximity of Sibanye-Stillwater's world-class J-M Reef deposit makes Stillwater West highly prospective for high-grade PGE-Ni-Cu reef deposits.
Drilling in 2023 confirmed continuity of the stratiform pegmatoidal reef-type "A-B" chromitite zone discovered on Chrome Mountain, providing an important foundation for follow-up drill campaigns. Drillhole CM2023-05 also intersected two chromite-rich high-grade PGE horizons towards the bottom part of the hole. These zones returned significant PGE+Ni-Cu mineralization characteristic of the stratiform reef-type high-grade "A-B" chromitite, containing a high-grade zone of 2.79 g/t PGE+Au, plus also 0.31% Ni, 0.20% Cu, and 0.018% Co over 4.8 meters in hole CM2023-05.