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Mawson Gold recently announced that they have doubled the NI 43-101 resource estimate at their Rajapalot Au-Co project (See NR 14.9.20) (Figure 1) in Finland. The previous estimate was produced in late 2018. Since then Mawson have cracked the code of the geological model at Rajapalot allowing them to explore more strategically and to great effect, as evidenced by the new resource estimate. I caught up with Mike Hudson to get into the nitty gritty of the geology, and how Mawson will continue to advance the strategic project.
Inferred mineral resources have increased to 9 million tonnes at 2.1 g/t Au and 570ppm Co. This equates to 716,000oz @ 2.5 g/t AuEq. Approximately 70% of the resource is planned to be mined open pit, at a cut off grade of 0.3 g/t AuEq. The estimate is a combined total of three resource areas Raja, Palokas, and Rumajärvi.
Located in the Peräpohja Greenstone Belt, Rajapalot has undergone significant multi-phase deformation and metamorphism to upper amphibolite facies. This complexity of the structural history is common the Peräpohja with many debates in the literature over the exact number of deformation phases. At Rajapalot, gold is found to be post peak deformation (~1.78Ga) and potentially associated with 1.78Gyr tourmaline bearing granites. Mike cites the tag line for Rajapalot as “We get excited in the dark” owing to the association of scheelite with gold and its fluorescent nature.
The host rock package containing the stratabound hosted but structurally controlled deposit begins from surface and is approximately 100m thick. Mineralised bodies are present at multiple levels within the package. Multiple bodies are 5-20m thick, up to 100m wide and are found to continue for over 800m down plunge. Geophysical methods suggest however the down-plunge extent may actually be over 1km. Host lithologies vary from potassium to magnesium-rich endmembers and overlap between the two distinct signatures can be found.
A tentative association is drawn between the prospectivity at Rajapalot and the presence of fold hinges. In fact, modelling of the deposit implies that resource-defined areas may lie on opposing fold limbs and that mineralisation continuity is therefore likely between them (Figure 2). Although not a specific target at Rajapalot, the possible association will hopefully become apparent as work continues and have implications for other synchronous orogenic gold deposits in the Peräpohja.
Gold is associated with but not contained in pyrrhotite and is variably associated with cobalt; generally, gold is less abundant on the margins of the deposit where pyrite is present over pyrrhotite but cobalt can remain in high concentrations. Where gold and cobalt are found together they are intimately associated owing to their synchronous enrichment. You may wonder what the processing implications are of this but the full answer is pending. Gold is free and liberates well with gravity separation and cyanide, and also via flotation with very good recoveries. Cobalt, which is present as cobaltite and linnaeite, can be extracted using gravity, and then either magnetic or float separation with subsequent leaching. Work remains to fine tune this process and make the most of the excellent grades at Rajapalot.
It is gaining in-depth understanding of the geology and mineralisation that has allowed Mawson to define several targeting parameters and the upcoming drill season is the first time they will be able to apply their understanding to new targets to (hopefully) great effect. Geological targets include an iron-rich host, a late gold overprint and the confluence of late structural controls. The latter is particularly important as it increases the interconnectedness of gold-associated sulphides, giving a more continuous conductive signature. Sort of like follow the variably bronze-coloured brick road. Such geophysical responses are key for exploration in areas with extensive overburden cover, at Rajapalot glacial till covers 99% of bedrock.
Mawson still have their work cut out for them to realise the true potential of Rajapalot but work is certainly what they will do. They currently have 1 drill rig on site and operating and are commencing a 20km, 5 rig program over the property in December to further expand their mineral resources. Current drilling is testing two areas (Figure 3): the 3km long Hirvimaa area 500m north of the Palokas resource, and the 2km long East Joki area 1km northeast of the Raja resource. Targets were generated from an extensive base-of-till (BoT) survey as well as airborne VTEMplus data and ground TEM electromagnetic data, as well as their geological and lithogeochemical models.
The 20km program will test high grade mineralisation trends as well as investigate the extent of mineralised bodies which to date are all open at depth. It is hoped this will increase near-surface tonnage that can be incorporated into the open pit-able resource. Using geophysical and BoT data, the Company will generate further targets fitting the geological model for incorporation into the drill program.
The nearby operating Kittila mine (Agnico Eagle) has an estimated 29Mt at 4.4 g/t Au, and Mike can see Rajapalot potentially growing a similar way. As well as testing new targets this winter, Mawson have a 10x10km area left to explore which extends back to Rompas where they have defined a different style of gold mineralisation, formed during the same geological event, that includes Mawson drill results of 6 metres @ 617 g/t gold including 1 metre @ 3,540 g/t gold. Mawson has tested about 5% of the total 65km of host stratigraphy.
The presence of cobalt in Rajapalot is more than economically significant. It is one of the only compliant cobalt resources in Europe, and production would offset some of the supply currently required from the DRC. Mawson have joined the European Raw Material’s Alliance as a result of this. The new alliance aims to help stabilise and de-risk Europe’s critical and raw material supply chain in the face of a technologically intensive future. Rajapalot has been recognised as important to this goal, and for Mawson this represents a great deal of support for their project and their presence in Europe.
All information in the above article is sourced from Mawson Resources’ website and materials within, as well as personal communications with Mike Hudson (CEO & Chairman).
 - Resource update NR: https://bit.ly/2Fo70FC
NI43-101 Technical Report: https://bit.ly/34RVbQH
European Raw Materials Alliance: https://erma.eu/
https://bit.ly/2GWHtns (Mawson NR on alliance)