The Samapleu-Grata-Yepleu Ni-Cu-PGE deposits, Yacouba Intrusive Complex
Western Côte d’Ivoire
Samapleu-Grata-Yepleu project: 2023 Technical Studies
In 2023, Ivanhoe Electric and Sama Resources through his subsidies Sama Nickel Corporation (SNC) have launched the process for a revised mineral resource at the Samapleu and Grata deposits combined with the engineering firm BBA International Inc. Additional technical studies are currently ongoing with the engineering and environmental firm Knight Piésold Consulting. It is the intention to update mineral resources in 2023 including both sectors: Samapleu and Grata.
Figure 1: Sama Nickel Corporation; exploration permits in Côte d’Ivoire.
Figure 2: Samapleu, Zérégouiné, Zoupleu and Grata Exploration Permits showing 2013-18 Airborne EM targets remaining to be explored (shown by blue circles).
Figure 3: Newly discovered sector at Grata property located 5 km East of Samapleu. A total of 45 holes for 14,995m were drilled at Grata since the discovery in June 2021.
Samapleu Property (PR 838 & 839)
SNC entered into a Syndicate Agreement (“SA”) with SODEMI, a parastatal organization, under which SNC is responsible to finance, on behalf of the SA, exploration work programs during the exploration phase through completion of a Bankable Feasibility Study (“BFS”) on the exploration permits Samapleu East (PR 838) and Samapleu West (PR 839) held by SODEMI.
SODEMI will not contribute to work conducted under the SA. Both PRs expire on June 17, 2023, with possible renewal periods totaling up to 12 years. SNC was required to complete an exploration program before the term of the exploration permit. This exploration program was completed on time and on March 1, 2023, SNC filed the required documentation with the Department of Mines in Côte d’Ivoire, for the renewal of PR 838 and PR 839 which should expire on June 17, 2026.
Upon completion of the BFS, the Advisory Committee (“AC”), which consists of two SNC representatives and two SODEMI representatives, will conclude on the feasibility of the project. If the AC decides to proceed with the project, an Exploitation Entity (“EE”) will be established whereby future funding will be split between SNC and SODEMI at 66.7% and 33.3%, respectively.
The EE will reimburse SODEMI for all costs associated with previous exploration work conducted until January 15, 2009 up to a maximum of F CFA 834,999,457 (approximately $1,714,085 as at December 31, 2022) and will reimburse SNC for costs associated with exploration work conducted between the signature of the SA and the approval of the BFS subject to the approval of the AC which represents a total amount of $25,632,093 as at December 31, 2022.
The ownership of the EE on (PR 838 and PR 829 only), shall be allocated as follows:
SNC | 60% |
SODEMI | 30% |
Government Côte d’Ivoire | 10% |
| 100% |
The Samapleu Property is subject to a 1% net smelter return royalty.
Figure 4: Hole SM44-428267 intersected 54 m of mineralized pyroxenite, grading 0.96% nickel, 0.76% copper and 0.74 gpt palladium, including a combined 8.0 m of massive sulphide grading 4.08% nickel, 2.43% copper & 2.92 gpt palladium at the Samapleu Main deposit.
Samapleu-Grata Nickel-Copper Type Mineralization
Since 2009, the Company’s regional exploration work highlights the prospective potential of the entire Sama’s prospective areas. In addition to the Samapleu Main deposit and the nickel-cobalt rich laterite Sipilou South deposit, there were several mineralized sectors that have been identified within the PR 838 (formerly old PR123) area, including the Company’s discovered Samapleu Extension 1 deposit, the Yorodougou and Bounta occurrences. as well as numerous massive chromite showings, all part of the newly discovered Yacouba Intrusive Complex.
The Samapleu and Grata deposits mineralization and their geological characteristics are typical of a Pipe like intrusion or conduit‐hosted nickel deposits. These rare types of intrusions host the world’s largest nickel‐copper deposits such as: Jinchuan, Voisey Bay, Kabanga, Eagle, Eagle Nest, Kalatongke and N’komati.
The Yacouba Intrusive Complex’s mafic and ultramafic hosts were intruded within the older gneissic assemblage of the West Africa’s craton. It is interesting to note that the age (2.1Ga) of the Yacouba Intrusive Complex is almost the same as that of the large and mineral rich South-African Bushveld Complex (host of the Ivanhoe’s large Flatreef palladium-Nickel deposit and numerous other chromite+ Platinoid Group Elements deposits as well as the nearby N’Komati nickel-copper-palladium deposit).
Samapleu and Grata deposits are typical magmatic nickel‐copper Platinum group elements (“PGE”) deposits with common metallurgical characteristics. Nickel and copper mineralization (pentlandite, chalcopyrite, combined with pyrrhotite, rarely pyrite) correspond to sulphide disseminations ranging from trace to 40% and semi-massive to massive (40% to 100% sulphides – Figure 4) sulphide rich lenses commonly spatially associated with a strong brecciated texture in mostly pyroxenites.
The semi-massive and massive sulfide veins display a number of characteristics suggesting that they are part of a larger mineralizing system:
- Extreme variations in nickel/copper ratio indicative of fractionation of sulphides.
- Association with varied textured and brecciated facies.
- Presence of an unusual texture called loop texture. Large pyrrhotite crystals (5 centimeters in diameter) are rimmed by smaller chalcopyrite and pentlandite that define a loop that encloses the pyrrhotite. These textures are seen at Norilsk and Voisey’s Bay nickel-copper-PGE deposits.
- Abundant sulfide inclusions (globules) within pyroxene crystals indicating that sulfur (S) saturation took place before pyroxene crystallization (at depth).
It is to be noted that the mineralization is open at depth at the Samapleu and at Grata deposits and remains mostly untested below 200 m from the surface. The mineralization is also open along strike at the Samapleu Extension 1 as per recent drilling outlined. The Company’s regional compilation and exploration work highlights the highly prospective potential of the whole area surrounding these known intersections, including the Yepleu discovery located 18 kilometers SW in the PR 300 (Figure 1) and numerous prospective targets/zones with SNC’s property package.
In the past years, the Company completed a 13,500 line-kilometer airborne magnetometer and radiometric survey over the Samapleu Property in 2012; a 3,900 line-kilometer of airborne helicopter time domain electromagnetic and magnetic survey (“HTEM”) in 2013; a 60 line-kilometer of InfiniTEM ground geophysical survey over Samapleu Main and Extension 1 deposits and the Yepleu Complex in 2013 and an additional 2,889 line-kilometer of airborne helicopter time domain electromagnetic and magnetic survey (“HTEM”) in 2018.
More than 30 priority targets representing a potential for additional nickel-copper-platinum group elements mineralization have been outlined. Strong conductors were identified at the Samapleu Main and Samapleu Extension 1 deposits as well as along a corridor of more than 40 km oriented north-east (Figures 2 & 5).
In 2013, the Company purchased its first Cortech track mounted CSD1300G wire line drill rig. A second drill rig was purchased in 2014 and was sold in 2016. A second-hand Boart Longyear DB525 drill rig was purchased in 2019 replacement of the drill rig sold in 2016. A new drilling rig (Cortech 3000) has been purchased and arrived on site in February 2020. This new rig is able to reach depth in excess of 1,500 m. Table 1 summarizes drilling programs since July 2010.
Table 1: Drilling programs from July 2010 to November 2022.
Near surface exploration at the Samapleu Project (< 150 m deep) returned centrally located massive sulphide vein stock works encased in a thick halo of disseminated sulphide. Tenors of up to 4-5% Ni and 6-8% Cu, respectively, were obtained in massive sulphide material.
In January and February 2018, Geotech Ltd., completed a 2,889 line-kilometer HTEM survey over the Samapleu and Yepleu areas (PR 300). The HTEM Survey was flown over the area at 200-meter line spacing, using their Versatile Time-Domain Electromagnetic geophysical system. The survey was completed in February 2018.
Figure 5: Samapleu Project: Magnetic inversion showing several feeders of the Yacouba complex: more than 20 targets zones remaining to be investigated (blue circles).
Mineral Resource update May 27, 2020
On December 22, 2015, the Company filed a revised NI 43-101 compliant mineral resource estimate on the Samapleu Property. The revised mineral resource estimate includes an indicated mineral resource of 14.1 Mt grading 0.24% Ni and 0.20% Cu and containing 74.5 Mlb of Ni and 61.2 Mlb of Cu, together with an inferred mineral resource of 26.5 Mt grading 0.24% Ni and 0.18% Cu and containing 134 Mlb of Ni and 107.2 Mlb of Cu (Table 2).
The engineering group DRA/Met-Chem produced a technical study for a possible open pit operation at Samapleu. The processing treatment included concentration via flotation process with further processing to nickel and iron powders using CVMR’s processing technology. On May 27, 2020, the Company announced the positive preliminary economic assessment for the development of the Samapleu Ni-Cu surface mineralization. The study includes a revised mineral resource using all boreholes drilled at the Samapleu deposit.
The Company is currently investigating the possibility to fast tracking detailed technical studies for a possible open pit type of exploitation at Samapleu and the newly discovered Grata deposits.
Table 2: Samapleu Project Mineral Resources Summary (Cut-Off Grade of 0.1% NiEq) May 2020.
Category | Resources (Mt) | NiEq (%) | Ni (%) |
Measured 1,2,3 | – | – | – |
Indicated 1,2,3 | 33.18 | 0.269 | 0.238 |
Meas. + Ind. | 33.18 | 0.269 | 0.238 |
Inferred 1,2,3,4 | 17.78 | 0.248 | 0.224 |
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Zérégouiné Property (PR 300)
SNC owns the exploration permit No. 300 (“PR 300”) which covers 290 square kilometers of property in Côte d’Ivoire and expired on December 17, 2023. In accordance with PR 300, SNC was required to complete an exploration program before the term of the exploration permit. This exploration program was completed on time and on September 20, 2021, SNC filed the required documentation with the Department of Mines in Côte d’Ivoire, for the exceptional renewal of PR 300 which should expire on December 18, 2023. As of today, there is no indication that the exploration permit will not be granted.
Yepleu Occurrence
On June 6, 2013, the Company announced the discovery of mineralized surface outcrops grading up to 1.39% nickel and 2.26% copper (tested using a hand-held Niton XRF analyzer) located 18 km southwest of the Samapleu nickel-copper deposit.
The occurrence, named Yepleu, covers an area of 24 km2 in the NE corner of the Zérégouiné Exploration Permit. Outcrops with up to 25% disseminated sulphide mineralization in mafic and ultramafic rocks and strong mineralization are seen at surface along a NW-SE strike length of 1.7 km, with some of them showing continuous mineralized horizon of up to 25 m in strike length.
The sector shows a strong HTEM conductivity covering an area of 6 km by 4 km with extension to the SW over more than 17 km (Figure 2).
The disseminated mineralization is typically characterized by fine isolated grains to large granular aggregates of nickel, copper and iron sulphides. Sulphide phases observed so far include pyrrhotite, chalcopyrite, pentlandite and minor pyrite. Pentlandite occurs as inclusions in pyrrhotite. Disseminated sulphide occurs as fine grains of 0.5 to 1 millimeter in diameter, showing a high ratio of pyrrhotite versus chalcopyrite. Sulphide veinlets and fine filaments are also present. Composite grains of sulphide material are dominant, forming sulphide masses of odd shapes ranging from a few millimeters up to several centimeters in any one dimension. The semi-massive mineralization lenses show between 30% to 70% sulphide minerals.
The Company performed a first phase of Typhoon survey in August 2018 and began the phase 2 Typhoon survey on April 1, 2019. Five holes for 4,191 m were drilled by Capital Drilling in the first half of 2019 and have intersected new mineralization at the Yepleu Sector 1 (Figure 6).
The hole YE29-556043 returned results with a combined 5.2 m of semi-massive sulfides grading 1.16% Ni, 0.62% Cu, 0.24 gpt Pd and 0.21 gpt platinum (using a cut-off-grade of 0.8% Ni) within a larger interval of 37 m of disseminated sulphide mineralization grading 0.41% Ni, 0.31% Cu, 0.23 gpt Pd and 0.17 gpt platinum. A second hole drilled at the Yepleu Sector 1 as follow-up on the mineralized zone intersected on the first deep hole (YE29-556043) returned a mineralized zone of 54 m of disseminated to semi-massive and massive sulfide material from 585 m to 639 m from the surface.
Two additional holes were drilled subsequently as follow-up on the mineralized zone intersected on the first deep hole. Hole YE29-553044 returned a mineralized zone of 54 meters of disseminated to semi-massive and massive sulfide material from 585 m to 639 m from the surface. The second hole, YE22-225440 intersected 30 meters of disseminated to semi-massive and massive sulphide, including 1.7 m of massive sulphide (> 70% sulphide).
- The Company’s discovered mineralization at 600 m at depth at the Sector 1 within the Yepleu license and within the newly discovered Yacouba Intrusive Complex (dated as the same age as the Bushveld Complex in RSA (2.1 Ga) which host the large nickel-palladium Platreef deposit) is another evidence that the Yacouba intrusion system has the potential to host a significant amount of high-grade nickel-copper-cobalt and palladium in reservoirs and pods that are yet to be discovered. Sama’s have outlined a strike length for the Yacouba Intrusive Complex of more than 66 km. The Yepleu area appears to be the center of the intrusion from where it seems to have “radiated” in all directions. This observation suggests that the Yepleu area is as proximal as we can get to the hot spot.
Figure 6: Sector 1 at the Yepleu property: The first deep drill hole (YE29-556043) intersected semi-massive sulfide mineralization with a combined 5.2-meter intersection grading 1.16% Ni, 0.62% Cu, 0.24 gpt Pd and 0.21 gpt Pt within a larger interval of 37 m of disseminated sulphide mineralisation grading 0.41% Ni, 0.31% Cu, 0.23 gpt Pd and 0.17 gpt Pt. Down-Hole EM survey, June 2019, return a very strong off-hole EM anomaly, 50 to 60 m SW and lower down from the YE22-225440.
Yepleu is the center of the intrusive feeder system with evidence of multiple magma injections generating a large volume of host rock assimilation (Figure 7).
Figure 7: Schematic visualization of the Yacouba intrusive complex showing proposed targets at Samapleu, Grata and Yepleu
Grata property (PR 604)
SNC owns the exploration permit No. 604 (“PR 604”) which covers 92 square kilometers of property in Côte d’Ivoire and expired on December 7, 2025.
The property is located adjacent to the north-eastern boundary of the former Samapleu exploration permit. Sama believes that ultramafic sequences of the recently outlined large Yacouba Intrusive Complex which hosts the Samapleu Nickel-Copper-Palladium deposits, are extending within the Grata Permit and as such represent a prime target for nickel-copper-palladium mineralization.
In September 2021, Sama announced the Grata discovery located 5 km east of the Samapleu deposit. The discovery hole, GR-03, drilled in June 2021, returned a 310 m sequence of pyroxenite and gabbro containing a 147 m interval of disseminated sulfides and several intersections of semi-massive sulphide mineralization. The following are highlights: Hole GR-25 which intersected a combined 179.85 m of mineralization including 37.40 m at 0.24% Ni, 0.45% Cu and 0.54 gpt Pd and 116.95 m at 0.23% Ni, 0.23% Cu and 0.32 gpt Pd and hole GR-28 returning 194 m of combined mineralized zones including 97.85 m grading 0.30% Ni, 0.34% Cu and 0.24 gpt Pd. GR-11 drilled in January 2022 along the same section returned 212 m of combined mineralized zones including 8.20 m at 0.84% Ni, 1.10% Cu and 1.24 gpt Pd, with several narrow massive and semi-massive stringers scattered through the mineralized intervals. Holes GR-32 and GR-35 which intersected 138 m and 132 m of combined mineralized zones, respectively. Hole GR-35 included 12.40 m grading 0.39% Ni, 0.53% Cu and 0.44 gpt Pd and 78.50 m grading 0.27% Ni, 0.42% Cu and 0.25 gpt Pd. These two holes confirm the extension of mineralization toward the north-east.
Figures 8 and 9 are showing hole locations and a longitudinal cross section at the Grata occurrence.
Figure 8: Grata new discovery: drill holes location and geology.
Figure 9: Grata discovery: SW-NE longitudinal cross section
- Reported widths are “combined drilled widths at cut-off grade,” not true widths.
- NickelEq%=((nickel%/100)*17,632)+((copper%/100)*8,155)+((cobalt%/100)*52,896)+((Pt ppm)/31.1)*1,200)+((Pd ppm/31.1)*1,400)))/(US$ Nickel/t*100) using the following metal prices of US$ 17,632/t nickel, US$8,155/t copper, US$1,200.00/oz Pt and US$1,400/oz Pd. Assuming 100% recovery rates of sulphides to concentrate.
The mineralization at Grata is similar in composition to the Samapleu deposit but shows a larger proportion of chalcopyrite and therefore a higher copper to nickel ratio.
The Company is looking at increasing mineral resources at Samapleu and Grata for a future surface mining operation as well as searching for massive sulphide veins and lenses that could have accumulated at depth in traps and embayment’s along the feeder system of the Yacouba Intrusive Complex.