Mustajärvi Gold Project
The Mustajärvi Gold Project consists of a single exploration permit covering 146.53 hectares (1.47 km2) of flat, glacial till-covered terrain in the Lapland region of northern Finland, 17 km east of the town of Kittilä, with road and power on the property. The project is situated in the Central Lapland Greenstone Belt, which hosts several recent gold discoveries.
- With a total reported gold endowment of only 9.1 million ounces, The Central Lapland Greenstone Belt (CLGB) remains severely underexplored for orogenic gold deposits.
- Studies suggest there could be as much as 30 times the currently known gold resources in the CLGB1
- The observed gold mineralization, structural setting and work to date support the potential for a high-grade orogenic gold deposit on the Mustajärvi property.
- A detailed program including percussion drill till sampling followed by diamond core drilling is underway for the fully-permitted Mustajärvi area.
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. 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.
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 earliest two phases of ductile compression produced thrust faults, the most important of which are the Sirkka (STZ) and Venejoki (VTZ) thrust zones, both of which have been traced for >100 km. A third phase of ductile compression (D3) produced NE-striking strike-slip shear zones and reactivated or displaced the earlier thrusts.
Orogenic gold occurrences in the CLGB are associated with the STZ, the VTZ and the D3 shear zones. Suurikuusikko (Agnico-Eagle’s Kittila mine), with current reserves of 4.5 Moz Au and the most significant gold deposit found to date within the CLGB, is related to one of these NE-striking D3 shear zones (www.agnico-eagle.com; 07/2018).
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.
Most of the Mustajärvi property is covered by a few metres of glacial till and outcrop is scarce or non-existent. Regional mapping, which is largely based on geophysical interpretation, is not that accurate at the scale of the Mustajärvi property. The current regional interpretation suggests that most of the property is underlain by quartzite with a tongue of tholeiitic basalt that extends easterly from the southwestern end of the property.
This geophysical interpretation, at least with respect to the quartzite, does not appear to be correct. In the area outlined by Outokumpu’s drilling program, the dominant lithology appears to be a volcaniclastic rock as opposed to a quartzite.
Within these volcanic rocks the style of gold mineralization identified at Mustajarvi includes gold associated with pyrite-bearing quartz and quartz-tourmaline veins, which is typical of orogenic gold deposits. Combined with a favourable structural setting and good initial drill results, this makes the Mustajarvi property a good exploration prospect for identifying a significant orogenic gold deposit. The area of historic drilling is open in all directions, and the small size of the property allows FireFox to conduct a detailed program over most of the permitted area.
FireFox is conducting systematic exploration work in 2018, starting with mapping, geophysics and base of till (BOT) sampling to define drill targets. A drill campaign is expected to follow. For details on the program in progress please refer to the News Releases or the latest Presentation.
1Niiranen,T., I. Lahti, I., Nykanen, V.(2015) The Orogenic gold potential of the Central Lapland Greenstone Belt, Northern FennoscandianShield. In W.D. Maier, R. Lahtinen, H. O’Brien, Eds., Mineral Deposits of Finland (pp733-752). Elsevier Inc.