Projects
Peräpohja Schist Belt (PSB) Project
The PSB Project consists of one granted Exploration Licence, two Exploration Licence applications and one Reservation License within northern Finland, proximal to the Rovaniemi city in the Lapland region. The project is accessible by a robust infrastructure network consisting of road and rail, with Rovaniemi airport located just 40 km northwest from the project areas. All locations within the exploration tenements are within 2 km from the nearest gravel road (Figure 1).
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The Peräpohja Schist Belt is historically underexplored for orogenic gold but recent and historical Au discoveries indicate high discovery potential.
The PSB project is located adjacent to the Mawson Finland Limited Rajapalot project with published resources of 9.78 mt @ 2.8 g/t gold and 441 pm cobalt (Refer to figure 2).
Geology
The Peräpohja Schist Belt is a Paleoproterozoic supracrustal sequence deposited during rifting on top of Archaean basement. The northern and eastern part of the belt is bounded by the younger Central Lapland granitoid complex. At the southern border of the belt the basement contact is relatively intact with exposing the 2.44 Ga old layered intursions that are interpreted as being intruded during the onset of rifting. The S-N tending Pajala shear zone separates the Peräpohja belt from the Norbotten craton in the west. The Pajala shear zone is interpreted as a divergent plate boundary (Lahtinen et al. 2015).
The supracrustal sequence comprises of quartzites, mafic volcanics and volcaniclastics, carbonate rocks, black shales, mica schist and greywackes that were deposited ca. 2.44 to 1.88 Ga. The lowernmost stratigraphical unit in the project areas is the Sompujärvi formation conglomerate-quartzites followed by mafic volcanic rocks of the Pisaravaara formation. The main quartzite sequence is interpreted as belonging to the Palokivalo formation. There are also inferred evaporitic unit the Petäjäskoski formation within the sequence (Kyläkoski et al 2012). The sedimentary-volcanic sequence has been intruded by mafic intrusive rocks of the Koli sill suite, which are circa 2.2 Ga.
After initial deposition the belt has undergone multiple deformation stages with Lahtinen et. Al (2015) describing up-to five different deformation events. The earliest deformation stage D1 (≤1.91 Ga) generated a NS-trending S1 fabric and recumbent folds due to east-directed thin-skinned thrusting. NS-directed shortening in stage D2 (1.90–1.89 Ga) produced EW-trending folds and a pervasive, steeply dipping foliation. Stage D3 (1.88–1.87 Ga) is represented by NNW- and WNW-trending, heterogeneously developed structural trends. Traces of the D4 deformation (1.83–1.81 Ga) are most prominently seen as NNE-trending lineaments in aeromagnetic images. The last deformation stage (D5, 1.79–1.77 Ga) is characterized by WSW-shortening (Tapio et al 2021. direct citation).
There are at least nine known gold occurrences within the Peräpohja Schist Belt. Five of these are located along the Sihtuuna fault structure. The largest known Au-Co deposit is the Rajapalot located the northern part of the belt which was discovered in 2012. The belt has been under systematic gold exploration for relatively short time span with only a limited proportion of the belt being explored in detail.
Prospects
Petäjäinen and Reutu Prospects
Petäjäinen and Reutu prospects are located along the Sihtuuna structure, with the targeting hypothesis being that the Sihtuuna structure (Figure 3) is a deep reverse fault which is a multiply reactivated during tectonic events and it is inherited from a structure from the Archaean basement below (Piippo et al 2019).
LAT interpretation suggests that the Sihtuuna structure is an analogous structure to the Sirkka shear zone located in the similar age Central Lapland Greenstone Belt 150 km north (Figure 4). The age of the host rocks 2.05 – 2.3 Ga and deformation stages in Peräpohja schist belt link both areas into same orogenic event that formed the multi-million ounce deposits in the Central Lapland Greenstone Belt. Previously there were multiple smaller Au occurrences discovered along the Sirkka shear-zone before the discovery of 4.39 moz Au Ikkari deposit in 2020. The Sihtuuna Fault is at the state right now where smaller Au occurrences along the structure have been discovered.Peräpohja Schist belt has the right framework to host multi-million ounce gold deposits and only lacks systematic exploration.
LAT field work between 2020 and 2024 has returned a clear 16 km long Au-Cu anomaly from bedrock rock-chips and boulder samples (Figure 5). If historical Au occurrences to the west are taken into account, the structure seems to be auriferously active for at least 46 km (Figure 5). LAT has defined two key project areas along this structure where the exploration work will focus on interpreted structural traps that could host large economic orogenic Au deposits. In additional to gold, a strong pathfinder enrichment is evident in the rock-chip samples from bedrock and boulders including Co, As, W, Te, Ag, Mo; with Co being a specific pathfinder for orogenic Au at Peräpohja Schist Belt and Kuusamo Schist Belt.
In 2021 LAT conducted a SkyTEM survey on the northern part of the area covering Reutu prospects completely. This survey identified strong SkyTEM electrical conductors along the Sihtuuna fault and associated 2nd and 3rd order structures. These conductors remain untested by drilling with overburden covering the projected surface position of the anomalies. Only boulders have been recorded on top of conductors. The Sihtuuna fault is mostly unexposed which could be explained by weathering of the sheared rock along the fault and deposition of glacial sediments on the weathered depression.
Reutu targeting information
The Reutu prospect is interpreted as being coincident with the continuation of the Sihtuuna Fault. The fault structure itself is not exposed. LAT skyTEM survey (2021) shows two conductive targets along interpreted fault structures (Figure 5). The Reutu 1 target, located along the main Sihtuuna Fault, is associated with a strong north-dipping conductor with dimensions of 800m x 500m, and is coincident with a local flexure in the Sihtuuna fault where the mafic intrusive rocks to the north, show potential demagnetisation. The Reutu 2 target is a 4.4km long string of SE-NW trending conductors along an interpreted 2nd or third order fault that is offsetting mafic intrusive units. These conductors do not appear to be stratigraphic, as their orientation is perpendicular to the regional geological trend. The defined conductors at Reutu 1 and Reutu 2 remain unresolved as to their origin.
Petäjäinen targeting information
The Petäjäinen prospect is defined by a strong Au-Cu anomaly footprint in quartz-sulphide and hydrothermal Au-Cu veins at an isoclinally folded mafic intrusive and sedimentary rock package on the NE side of the Sihtuuna Fault (Figure 6). The isoclinal fold hinges of the mafic unit are the main focus for current exploration activities, with historical drilling having intersected a previous intersection of 1m @ 19.6 g/t.
Vinsa Prospect
The Vinsa Prospect is located approximately 10km to the north-west of the Petäjäinen Prospect and is a vein hosted orogenic Au-Cu target, located within a SE-NW trending fold hinge (Kyläkoski 2022). The tenement is located 8 km south of the Mawson Finland Ltd Rajapalot Project. The Vinsa Au-Cu vein was discovered in 1966, and during the following decades numerous exploration efforts were made, but all the exploration work has been focused on relatively small area around the vein or south from it. LAT field work and data compilation work has shown that the Au-Co vein system spans over an area at least 1.25 km long and 0.4km wide with most samples being taken from bedrock. The targeting hypothesis is that these veins are distal manifestations of a hydrothermal system that lies west from the known outcropping area. West from the known vein outcrops, the bedrock is not exposed and covered by forest and swamps.
The historical Vinsa vein is a 1-1.5 m wide SE-NW trending and steeply NE dipping vein, filling a fracture or shear with a sinistral sense of movement. Further field work in the partially exposed eastern area (dark brown in Figure 7) area has revealed that there are two main orientations of Au-Co mineralised quartz (SW-NE striking veins and SW-NE striking veins).
LAT aims to focus exploration in the western area where there are apparent GTK airborne EM conductors and coincident demagnetisation of a large mafic intrusive unit. Planned next steps are ground based fixed loop EM survey to pin-point sulfidic veins followed up by geochemical sampling (BOT/RC).
