Mustajärvi Gold Project
The Mustajärvi Gold Project hosts gold-bearing drill intercepts striking over 2.1 kilometres, including multiple bonanza grade intervals, reaching up to 93g/t gold over 1.35 metres. Mineralization is open along strike and at depth.
The project consists of an exploration permit covering 1.5km2. The area is flat, glacial till-covered terrain in the Lapland region of northern Finland, 17 km east of the town of Kittilä, with a highway and power line crossing the property.
The project is situated in the Central Lapland Greenstone Belt, which hosts several recent gold discoveries. The observed gold mineralization, structural setting and work to date support the potential for a high-grade orogenic gold deposit on the Mustajärvi property.
The historical “Central Zone” of gold mineralization at Mustajärvi was the first of the zones to be identified. During the 2019 and 2020 seasons, exploration drilling by FireFox advanced to the northeast from the Central Zone and resulted in the identification of the Northeast Target. In 2021, the predictive 3-d modeling of the dilatant zones identified the East Target, which was first confirmed by gold intercepts in two holes drilled 650 metres further to the northeast.
The project now hosts gold-bearing drill intercepts over 2.1 kilometres. In addition, FireFox has now drilled six holes that returned > 90 gram-metres of gold mineralization from three different target areas at Mustajärvi. These intercepts occur along more than 1.5km strike of the shear zone. Examples of bonanza intervals include:
Hole 22MJ006 in the East Target returned a 13.85-metre interval averaging 14.39 g/t gold. Expressed in terms of grade-thickness, this interval measures 199 gram-meters of gold, the strongest mineralized interval yet drilled at Mustajärvi.
Hole 21MJ001 in the Northeast Target hosts visible gold and cut 1.35m averaging 93.88 g/t gold, including 0.65m at 129.5 g/t gold. Including two additional high-grade gold intervals of 5.27 g/t and 26.9 g/t, this drill hole returned a total grade thickness of more than 150 gram – metres of gold.
On-going drill programs continue to test for new mineralization along strike and at depth.
Location, Access and Infrastructure
Highway 80, which is part of the paved Finnish national highway grid, passes through the northern part of the Mustajärvi claim between the towns of Sodankylä and Kittilä. Both towns have populations ranging from 6,000 to 9,000.
Kittilä, which is 17 km west of Mustajärvi, is a winter travel destination with daily flights to Helsinki and other European cities in the winter, with fewer flights in other seasons.
A high-voltage power-line also cuts through the property. There is abundant water in the area and water rights could likely be obtained for milling.
The gold potential of the Mustajärvi property was first recognized in a late 1980’s governmental till survey. From 1990-1992, Outokompu Oy carried out till, magnetic and IP surveys on the Mustajärvi prospect, following up with trenching and diamond drilling.
The geophysics highlighted a NE-SW striking shear zone and the gold mineralization was found to be spatially associated with magnetic, IP, and chargeability anomalies.
Outokompu drilled 12 short holes within a 100 x 175 metre area of the east-west mineralized fault or shear to a vertical depth of less than 40 metres; 11 of their holes reported intersections exceeding 1 g/t gold with the best interval averaging 14.58 g/t gold along 2.70 metre core-length. Their drilling indicated that the east-west mineralized fault or shear dips at ~35° to the south and tested only a small portion of it. (The drilling suffered from significant core loss due to faulting and fracturing; widths may not represent true thickness.)
Outokompu allowed their mineral tenure to lapse in 1995.
In the early 2000’s, small-scale miners excavated a 20 x 70 metre pit, 2-5 metre deep, along the surface trace of the main mineralized zone (the Central Zone). Samples of gossanous material were reported from this pit by the property vendor with up to 17.4 and 79.8 g/t Au (Aurora, 2017). Well-mineralized boulders reportedly from the pit consisted of quartz-carbonate-pyrite±tourmaline veins with abundant goethite.
In 2017, Aurora geologists collected grab samples from trenches and boulders; one sample of sulfide-rich quartz vein material assayed 79.8 g/t gold.
While the Company believes the preceding historical drilling and sampling data are reliable, readers are cautioned that a “qualified person” (as defined by National Instrument 43-101) has not yet completed sufficient work to be able to verify the historical information, and therefore the information should not be relied upon. Outokumpu data retrieved from the Geological Survey of Finland (GTK) database. Aurora data provided by Aurora Exploration Oy.
Work Completed by Firefox through to January 2022
- Magnetic and Electromagnetic geophysical surveys outline potential deep structures on property
- Base of Till program outlined anomalous gold that was potentially related to interpreted structure
- Chip and channel sampling identified intersecting mineralized structures in the Central Zone
- Phase 1 Drill Program confirmed historic drill results and discovered new style of mineralization at depth.
- Encountered first mineralization coincident with Induced Polarization (IP) anomalies.
- Central zone outlined along 400 metre strike length and remains open along strike and at depth.
- Phase 2 Drill Program hit gold in two step-out holes, 500 metres northeast of the Central Zone
- Trenching and detailed sampling of key structures and alteration
- 9-hole Phase 3 Drill Program
- The Phase 4 drill program of 11 drill holes totalling 2,364 metres hit the first bonanza grades at the Northeast Zone
- The Phase 5 drill program identified high-grade at the East target and continued to expand the Northeast zone
Geology and Mineralization
The Mustajärvi property is located within the Central Lapland Greenstone Belt (“CLGB”), a poorly-explored package of Paleoproterozoic-age mafic volcanic and sedimentary rocks which underwent three ductile compressional events around 1.79-1.92 Ga followed by one or more brittle stages.
The Mustajärvi property is located between the Venejoki and Sirkka thrust zones. A NE-trending magnetic low passes along the axis of the Mustajärvi property for 2.6 km, possibly representing a second-order structure like that which hosts the Suurikuusikko deposit 33 km to the north.
The geology in the Mustajärvi area is dominated by the contact zone between the Sodankylä Group siliciclastic metasediments and the Savukoski Group ultramafic and mafic volcanics. This contact is usually gradational with mafic-ultramafic interlayers in the siliciclastic metasediments close to the contact zone. Black schists interlayered with mafic tuffs have been observed near the contact zone. The contact zone is thought to provide a major control for the gold mineralization due to the competency contrast between the lithologies, auriferous veins generally following the contact zones between mafic-ultramafic volcanics and siliciclastic metasediments. The oriented drill core, combined with the surface mapping in trenches, has provided much more insight into the structural controls on mineralization.
High-grade gold intervals are commonly hosted within quartz-carbonate-tourmaline (QCT) vein with abundant pyrite. The strongest mineralization to date at Mustajärvi has occurred in the footwall Sodankylä Group rocks, which are to the north of the shear zone. In this area, the Sodankylä Group includes metamorphosed sedimentary and volcaniclastic rocks. Along the alteration zone associated with the shear zone, these rocks have been made brittle by pre-gold pervasive alteration, including albite, silica, and sericite. Where these altered rocks are shattered, brecciated, and veined, high grade veins have been reported.