The AT 2 occurrence comprises copper-nickel mineralization, and is located 2 kilometres south of Ottarasko Mountain, 44 kilometres south of the community of Tatla Lake. Interest in the area began in 1983 with the discovery, during a regional geochemical survey, of an igneous boulder train containing disseminated copper-nickel-cobalt mineralization, including values of up to 1.5 per cent copper (Assessment Report 16688).
The area is underlain by a complex of imbricated thrusts involving volcanic and sedimentary rocks of Late Triassic and/or Lower Cretaceous Overlap assemblage rock. Rocks present include andesitic breccia, tuff and flows, and minor shale and limestone. These rocks and the thrusts are cut by a quartz diorite intrusion of the Jurassic to Tertiary Coast Plutonic Complex, dated at 68 million years (Late Cretaceous) by the uranium-lead method on zircon (Geological Survey of Canada Paper 88-1E).
Intrusive rocks occur mainly at lower elevations on the AT 2 claim and consist of mafic diorite and ultramafic rocks (Assessment Report 16688). Most pertinent to this occurrence are two zones of massive sulphide mineralization, each exposed over 5 to 10 square metres, comprising pyrite, pyrrhotite, chalcopyrite, pentlandite and unspecified associated cobalt minerals. These zones have been interpreted as magmatic segregations in the intrusive. Samples were analysed at up to 0.5 per cent copper, 0.4 per cent nickel and 0.1 per cent cobalt (Assessment Report 16688). Minor amounts of gold, silver, platinum and palladium were also recorded. However, these outcrops were thought not to be the source of the original boulder train of interest.
Near or at the contact with the volcanic rocks, there are zones or structures marked by pyritization, unspecified alteration and quartz or calcite veining. In particular, seven quartz-carbonate veins were located in the intrusive rocks, which are up to 150 by 40 metres, and which generally trend northwest and dip steeply. Mineralization is present but is not significant.
Other veins were located in volcanic rocks, one containing small amounts of sulphides and realgar and calcite. Up to 0.73 per cent copper occurs in one subcrop sample (Assessment Report 16688).
In 2018, Avalon Acquistion carried out prospecting and rock sampling from an approximately 400 metres by 600 metre area mainly within the intrusive rocks on the AT 2 claim, in the area of, and topographically above, the original discovery. Sampling was concentrated north and east of the exposed massive sulphide, magmatic segregation zones, as retreating glacial ice had exposed new bedrock in the mafic to ultramafic complex. Forty-five samples were sent for multi-element analyses. Assay values from outcrop reached as high as 0.058 per cent copper, 0.035 per cent nickel and 0.0074 per cent cobalt from ultramafic rocks; one ultramafic float sample yielded 0.012 copper, 0.051 per cent nickel and 0.0083 per cent cobalt (Assessment Report 39432). Some quartz plus/minus carbonate veins from within the Triassic volcanic units yielded anomalous results such as one sample assaying 0.065 per cent copper and 17.4 grams per tonne silver from a quartz vein (Assessment Report 39432).
The main feature of the UAV magnetic surveying is that it showed the government-flown aeromagnetic anomaly in much greater detail which resulted in a superior interpretation. The broad government anomaly is revealed to consist of three strong linear-shaped magnetic highs that are thought to have been caused by a gabbroic phase of the underlying intrusive. It also revealed exploration targets to consist of possible magmatic nickel- copper mineralization:
1) to occur within the magnetic highs. One of the highs contains rock samples with anomalous values in nickel,
2) to occur on the boundaries with the highs. A gossanous zone with a rock sample highly anomalous in copper occurs along the northern edge of one of the highs,
3) to occur along magnetic lineations that are indicative of structural zones such as faults,
4) to occur within weaker highs which is quite common. A weaker high occurs to the north of the float at the AT 2 showing and may be its source.
WORK HISTORY
In 1983, prospector Louis Berniolles located a mineralized boulder train trending west-south-west from the south-facing glacier of Mount Ottarasko. The mineralization was mostly disseminated chalcopyrite in a medium-to-dark grey igneous rock. The tenor was reported to be approximately 1.5 per cent copper, with minor quantities of nickel and cobalt. In 1984, Berniolles staked the AT 2 claim to cover the area to the east of the boulder train, the presumed source of the boulder train. Little work was done on the claim until 1987.
In 1987, claim owner Louis Berniolles and crew prospected all accessible areas of the 100 hectare AT 2 claim for a total of 46 man/days. A total of 18 samples were sent for analysis. The purpose of the prospecting was to find the source of the mineralized boulder train that had been found by Berniolles in 1983. The source of the boulders was not found in 1987.
In 2017, the AT Property (consisting of the AT 2, AT 5, AT 6 and AT 7 claims) was staked by in 2017 by Ron Fischer and George Nicholson.
In 2018, a regional geophysical study was carried out commissioned SJ Geophysics on behalf of owner Ronald Fisher which resulted in the observation that the property was largely underlain by a government aeromagnetic anomaly that closely correlated with the tonalite intrusion. Inversion modelling determined that the source of the high was a nearly cylindrical (slightly elongated NE-SW) core, approximately 3 kilometre in diameter, centred near the middle of the AT Property. This core approaches to within approximately 300 metres of the surface. This interpreted core is smaller than the mapped tonalite indicating that it is a different rock-type, thought to be a phase of the broader intrusive. Later in 2018, a 3-man crew carried out prospecting and rock sampling over an area of about 400 metres by 600 metres. Forty-six samples were collected and sent for analyses.
In 2020, operator Avalon Acquisitions Corp. completed a program of UAV drone photogrammetry over 500 hectares and a UAV hexacopter (drone?) airborne magnetic survey over 68.7 line-kilometres.
