A northwest trending, 1830 by 1340 metre intrusive-extrusive acidic complex of the Tertiary Sloko Group is cored by quartz feldspar porphyry and includes plagioclase porphyry, felsite and breccia. The complex appears to have intruded the contact between pre-Upper Triassic metasediments and volcanics, and porphyritic andesite, rhyolite and tuff of the Upper Triassic Stuhini Group.

The acid complex, its few satellites and peripheral rocks are extensively pyritized, hydrothermally altered and locally mineralized. Alteration minerals include sericite, epidote, saussurite, muscovite, jarosite, kaolinite, hematite and carbonate minerals.

Mineralized shear zones in the intrusion contain tetrahedrite, enargite, pyrite and stibnite, occurring as disseminations and in narrow quartz veins.

An east trending silicified and pyritized breccia zone, up to 250 metres wide and about 600 metres long, is associated with the altered porphyry. Within the breccia zone, tetrahedrite, enargite and pyrite occur as disseminations and in narrow quartz veins. The zone includes the Main target or Stringer Zone, to the west, and the East Zone and East Extension. Later the Main target name was not used, and the area included the E zone and the Tamdhu and Catto veins. The historical entanglement of names is not easily separated in this area.

The original Main Target zone contains a 15 centimetre wide tetrahedrite veins. A sample from the vein assayed 33.71 per cent copper, 868 grams per tonne silver and 7.54 grams per tonne gold (Assessment Report 2512). Nearby, a 7 metre wide area contained 1 to 15 centimetre wide veins with tetrahedrite, enargite, pyrite and quartz. A 1 metre chip sample across the area assayed 4.75 per cent copper, 164 grams per tonne silver and 2.0 grams per tonne gold (Assessment Report 11923). A drill hole to the southeast of the mineralized area intersected 3.78 per cent copper, 152.6 grams per tonne silver and 2.0 grams per tonne gold over 2.58 metres (Assessment Report 15892).

The East Zone, which lies 300 metres east of the drilled area on the Main Target Zone, consists of several parallel silicified and brecciated vertical structures, over a 30 metre width, within the altered porphyry. The silicified structures contain massive quartz with large pockets of pyrite and minor enargite or tetrahedrite. The zone strikes 070 degrees for 1200 metres.

A 3.7-metre sample from a trench assayed 0.03 per cent copper, 312 grams per tonne silver and 8.6 grams per tonne gold (Assessment Report 2512). A drill hole intersected 35.3 grams per tonne silver, 0.07 per cent copper, and 2.7 grams per tonne gold over 10.29 metres (Assessment Report 15897).

The East Extension Zone lies 200 metres east of the East Zone and may be the same zone offset by a fault. It consists of silicified porphyry carrying some pyrite, arsenopyrite and minor tetrahedrite and chalcopyrite.

Northwest of the Main Target Zone is a 30 metre halo of altered andesite, adjacent to the porphyry. The andesite contains massive blebs and stringers of chalcopyrite, pyrite and pyrrhotite. Epidote and minor magnetite are associated with this alteration. Minor sporatic exploration since 1963 identified numerous zones of mineralized veining exposed over a 2 by 1.5 kilometre area.

The Catto vein comprises massive pyrite, enargite and tetrahedrite in a matrix of white sericite, located within fine-grained FQB porphyry (uKPO2) a few metres east of its fault contact with Stuhini Group andesite. Hole 86-6 probably hit the Catto Vein about 50 metres north along strike and 80 metres downdip from its surface exposure, intersecting 2.8 metres (about 1.7 metres true width) grading 4.0 per cent copper, 1.9 grams per tonne gold and 156 grams per tonne silver (Assessment Report 26433).

The Tamdhu vein is exposed on the jarosite bluffs across from the junction of Camp and La Jaune Creeks. The main exposure of the vein trends 080 degrees and dips 50 degrees south, consisting of 90-centimetres of semi-massive pyrite-enargite-tetrahedrite and 120-centimetre of chalcedonic quartz with lesser sulphides. A second quartz-pyrite vein, located 5 metres to the south, strikes roughly parallel, but dips steeply to the north and appears to form part of the Tamdhu vein zone. Petrographic analysis has identified the presence of minor to trace amounts of stannite, stibnite, acanthite-argentite, pearcite-polybasite, hübnerite, galena and a Ag-telluride, mainly associated with tetrahedrite and enargite. The Tamdhu was discovered in 2000 (Assessment Report 26433, 27120). Gold-rich pyrite-enargite-tetrahedrite-quartz boulders found beside La Jaune Creek were traced upslope to a 2.1 metre wide quartz-sulphide vein which was thought to be their source and which was drilled in 2002. Sample 206997 was taken from one of these boulders, assaying 20.2 grams per tonne gold, 2261 grams per tonne Ag and 9.84 per cent copper (Assessment Report 27120).

The E Zone, located in Gelb Creek, was described by Anaconda as a northerly-trending shear zone mineralized with chalcopyrite, pyrite and quartz, located within andesite near its contact with the FQB porphyry. Their chip sampling graded 0.95 per cent copper, 0.28 gram per tonne gold and 15.5 gram per tonne silver across 6.7 metres (Assessment Report 26433). They reported that the zone was exposed 30 metres further down Gelb Creek.

The Jarosite Bluffs zone, located across from the junction of Camp and La Jaune Creeks, hosts several narrower veins and systems of sheeted veinlets in addition to the Catto and Tamdhu veins. The veins and veinlets comprise quart-clay-pyrite-enargite-tetrahedrite and scorodite-stained fault slips.

The MP vein is a 50-centimetre-wide pyrite-enargite-tetrahedrite vein exposed in a small outcrop “island” surrounded by the boulders of Camp Creek, just above its junction with La Jaune Creek. It may form part of a wider vein system, covered by the creek alluvium. The MP vein is composed of massive medium-grained pyrite cut by irregular 1- to 10-millimetre-wide enargite-tetrahedrite seams and containing pockets of quartz. Petrographic analysis shows the presence of diaspore with the quartz, and minor chalcopyrite, galena, stannite and covellite as inclusions within tetrahedrite. Precious and base metal values do not extend into the vein’s sericitized porphyry wallrock.

The B Zone is exposed on surface as a resistant 1- to 3-metre-wide zone of quartz breccia and coalescing quartz veinlets, which outcrops along 40 metres on the northeast side of La Jaune Creek, south of the creeks’ junction with Camp Creek. Wallrock fragments of FQB porphyry within the quartz breccia have been altered to vuggy silica with remnant quartz phenocrysts or have been argillized and alunitized. Sulphide content in the main showing and in the drill holes under it is generally less than 1 per cent, although sub-crop and trench samples from its eastern extension contain up to 15 per cent pyrite, enargite and tetrahedrite. The B Zone can be traced intermittently for 260 metres along strike, trending 070 degrees and dipping 85 degrees south, with several right-lateral offsets of a few metres.

In 1986, a drill hole (86-3) drilled under the eastern end of the main outcrop, intersected 1.013 grams per tonne gold, 22.2 grams per tonne silver and 0.16 per cent copper over 41.50 metres (approximately 29.4 metres true width), including 7.8 metres (approximately 5.5 metres true width) grading 3.619 grams per tonne gold, 44.3 grams per tonne silver and 0.18 per cent copper (Baker, D. (2010-10-28): 2010 Technical Report on the Thorn Property).

The D zone was first identified by Julian Mining who had reported gold-bearing massive sulphide boulders west of La Jaune Creek approximately 100 metres southeast of the Tamdhu Vein. In 2003, a 15-centimetre wide pyritetetrahedrite-enargite vein hosted by strongly sericitized porphyry exposed along the southeastern bank of La Jaune Creek was identified. The vein is oriented at 087 degrees with a dip of 38 degrees south, roughly parallel to, and along strike of, the B Zone which is exposed on the opposite side of La Jaune Creek.

During 2000 through 2004, sampling of the veins and zones yielded values of up to 1.06 grams per tonne gold, 132 grams per tonne silver and 3.05 per cent copper over 2.25 metres from the Catto vein, 0.75 gram per tonne gold, 224 grams per tonne silver, 8.73 per cent copper and 0.249 per cent zinc over 0.5 metres from the MP vein, 4.17 grams per tonne gold, 320 grams per tonne silver and 1.25 per cent copper over 2.1 metres from the Tamdhu vein, 3.12 grams per tonne gold and 93.1 grams per tonne silver over 4.5 metres from the B zone, 7.22 grams per tonne gold, 418 grams per tonne silver and 0.496 per cent copper over 0.15 metre from the D zone and 0.13 gram per tonne gold, 696 grams per tonne silver, 1.85 per cent copper, 2.73 per cent lead and 0.295 per cent zinc over 0.4 metres from the E zone (Baker, D. (2010-10-28): 2010 Technical Report on the Thorn Property).

In 2002 and 2004, drilling on the veins and zones yielded intercepts including 3.10 grams per tonne gold, 454 grams per tonne silver and 3.65 per cent copper over 1.65 metres in hole 02-13 and 5.27 and 1.59 grams per tonne gold, 54.0 and 83.9 grams per tonne silver, 0.16 and 1.32 per cent copper, 0.67 and 0.02 per cent lead with 1.69 and 0.03 per cent zinc over 1.01 and 3.95 metres, respectively, in hole 04-31 from the Tamdhu vein and 1.70 and 1.11 grams per tonne gold, 89.6 and 368.9 grams per tonne silver, 1.40 and 2.96 per cent copper and 0.14 and 0.61 per cent zinc over 0.62 and 0.37 metres, respectively, in hole 04-30 on the MP vein (Baker, D. (2010-10-28): 2010 Technical Report on the Thorn Property).

Work History

Early exploration on the property was concentrated over a 6 square kilometre area and resulted in the discovery of more than 20 mineralized showings. The majority were found within the Camp Creek Structural Corridor, a 1.5 kilometre-long, northeast-trending structural zone easily identified by its large, bright gossans. Within the Camp Creek Corridor, high-grade gold-silver-copper occurs in vein-hosted massive sulphide mineralization, ranging in composition from pyrite-enargite + tetrahedrite (e.g. MP and Catto Veins) through quartz-pyrite-enargite-tetrahedrite + alunite veins and veinlets (e.g. Tamdhu Vein, 'F' Zone, 'I' Zone, 'L' Zone) to sulphide-poor quartz + alunite breccia and stockwork veins with clasts of vuggy silica (e.g. 'B' Zone). High-grade gold and silver mineralization is also associated with sulphides and sulphosalts (boulangerite-sphalerite-galena-pyrite) in the matrix between breccia clasts of a sericite-pyrite-ankerite altered heterolithic breccia (Oban Breccia Zone).

The earliest known work on the Thorn property was carried out by Kennco Explorations Western) Limited in 1959 during a regional exploration program. Kennco took a copper anomalous silt sample from the mouth of Camp Creek and followed it 1000 metres upstream, where they took a 37-metre chip sample across a silicified zone thought to be the A Zone.

Julian Mining Company, the Canadian arm of Anaconda, staked the Thorn property in 1963. They carried out three field seasons of mapping and prospecting, discovering 17 mineral showings of three main types: quartz-pyrite-tetrahedrite-enargite veins (Zones B, C, D, F, I, L and M). Limited diamond drilling was carried out in 1963 (4 holes; 71m) and 1965 (4 holes; 179m) on the A Zone, a quartz-barite-chalcopyrite-pyrite vein immediately south of the Thorn Stock.

The porphyry-style Cirque Zone, on the current Thorn 3 and 4 claims, was discovered in 1964. Following magnetic, IP and soil geochemical surveys, it was drilled in 1965 (8 holes; 889 metres). The remaining zones were evaluated by hand-trenching, chip sampling, limited soil sampling and reconnaissance magnetic and induced polarization survey lines. In 1969, American Uranium Limited carried out work on two small claim groups: the Ink, which covered the Thorn enargite-pyrite-tetrahedrite veins near the mouth of Camp Creek and the Lin over the Cirque Zone.

The Thorn showings were re-staked as the Daisy claims in 1981 by J. R. Woodcock, who carried out limited silt sampling and collected rock samples for geochemical and petrographic analysis. In 1983, Inland Recovery Group Ltd. acquired the Daisy claims and carried out mapping, soil sampling and VLF-EM surveying near the junction of Camp and La Jaune creeks. In 1986, Inland Recovery and American Reserve Mining Corp. drilled eight holes from three drill sites within the soil geochemical anomaly extending west from the B Zone. In 1989, the Daisy claims were optioned to Gulf International Minerals who carried out poorly documented chip sampling of some pyrite-enargite-tetrahedrite showings. No assays are available from this work and the claims were allowed to lapse.

The Thorn showings were re-staked in 1993 as the Check-mate claim by Clive Aspinall of Atlin. The following year, he split an addition 31 core samples from the 1986 drilling, commissioned petrographic analysis of six core specimens and a float boulder and re-interpreted the 1986 drill sections. An additional 11 core samples were taken from the 1986 drilling and 84 PIMA readings were taken from holes 86-1, 86-3 and 86-6, showing the predominance of illite, pyrophyllite and dickite in altered core.

Chevron Canada Limited staked the Outlaw 14 claims immediately southeast of Woodcocks Daisy claims in 1981. In 1982, Chevron ran soil lines up ridges and over a rough grid at 200 by 100 metre spacings, indicating the presence of a strong soil geochemical anomaly over an area of 400 by 1600 metres. The following year, a 50 by 50 metre soil grid was sampled over the heart of the anomaly. Five trenches were blasted across an easterly trending quartz-arsenopyrite-tourmaline. In 1985, five more trenches were blasted further east in a zone of intense clay alteration. In 1987, four holes were drilled along one section from two sites within this clay alteration zone.

In 1988, Shannon Energy Ltd. optioned the Outlaw property and carried out heavy mineral analysis of talus and silt samples, but no work was filed. Glider Developments Inc. acquired the property in 1991 and laid out 12.4 line-kilometres of soil grid over the heart of Chevron’s soil geochemical anomaly. Glider may also have drilled four holes on the Outlaw, but this work was never recorded and has not been confirmed.

Rimfire Minerals Corporation optioned the Check-mate and Stuart claims in February 2000, carried out an airborne magnetic/EM geophysical survey in July and staked the Thorn l-7 claims in August to extend the property over the Outlaw soil geochemical anomaly, the Cirque copper porphyry prospect and geophysical targets. Resistivity lows outlined the alteration flanking the high-sulphidation veins and extended them out under till blankets, while 26 weak EM conductors were identified in covered areas near altered porphyry and known veins. Fieldwork later that summer focused on the high-sulphidation veining within the Thorn Stock, resulting in the location and sampling of several previously reported zones and the discovery of two major new veins (Tamdhu and Catto). Soil samples were collected over an area measuring 1500 by 1600 metres across the Thorn Stock. All remaining unstamped core from the 1986 diamond drilling was split and analysed (Awmack, 2000).

Diamond drilling in 2002 by First Au Strategies Corp. and Rimfire Minerals tested 3 zones including the I zone. One vein assayed 9.3 grams per tonne gold, 760 grams per tonne silver and 0.3 per cent copper over 70 centimetres (Press Release, First Au Strategies Corp., October 10, 2002).

The Oban breccia zone was discovered in 2002 and is reported to be a 200 metre wide hydrothermal breccia that can be traced 160 metres along a north-south trend. An intensely sericitized breccia grab sample, containing interstitial sulphides, assayed 1260 grams per tonne silver, 5.32 grams per tonne gold, 5.8 per cent lead and 5.83 per cent zinc. Another 2002 discovery, west of the Oban zone, was the Glenlivet zone that is a 3-metre-wide quartz-pyrite-sericite vein that can be traced for 210 metres along strike. An assay highlight is reported at 2580grams per tonne silver, 20.39 grams per tonne gold and 23.9 per cent copper from a grab sample (PR REL Rimfire Minerals Corp., December 5, 2002). 2002 drilling targeted the I and Tamdhu zones as well as the Oban zone. Sulphosalts are reported to occur in the veins.

In 2003, Rimfire Minerals Corp. and Cangold Limited (formerly First Su Strategies) performed a trenching and drilling program. Trenching in the Oban breccia with a helicopter-transported excavator was unable to expose mineralized bedrock but helped select drill targets in a strong multi-element soil anomaly. Eight holes totaling 874 metres were completed.

In 2004, Cangold Limited and Rimfire Minerals drilled the Oban Breccia polymetallic zone, as well as several other untested anomalies on their Thorn property. Drilling comprised 12 holes and totaled 1810 meters. Four holes tested the Oban zone along strike and at depth and five holes tested new IP anomalies. In 2004, Cangold Limited and Rimfire Minerals discovered the Balvenie and Cragganmore zones (MINFILE 104K 131, 132 and 133) and drilled one hole at the Balvenie in 2005.

In 2005, Cangold Limited and Rimfire Minerals Corporation continued exploration by a program of geological mapping, geophysics and drilling. Five holes were completed, totaling 656 metres. Hole THN05-37 intersected 4.44 gram per tonne gold, 407.9 gram per tonne silver and 2.95 per cent copper over 4.2 metres in the Talisker zone, discovered in 2004. The host rock in the Talisker zone is strongly sericitized, quartz and biotite porphyritic Thorn stock.

In April 2008 Rimfire purchased Cangold's interest in the Thorn Property.

In 2009 Rimfire and Geoinformatics combined to become Kiska Metals Corporation. In 2010 Kiska optioned 51 per cent of the Thorn property to Brixton Metals Corporation. In 2010, Brixton commissioned an airborne geophysical survey, extending magnetic coverage over the Windy Table volcanic rocks to the northeast of the 2000 airborne survey and using (VTEM time-domain EM) to attempt to see through the Windy Table rocks to hypothesized high-sulphidation alteration zones in the underlying Thorn Stock. Two previoiusly known corridors of alteration and veining, Camp Creek and Talisker, are marked by broad conductive zones in the 2010 VTEM survey; these conductive zones are confined to the area underlain by the Thorn Stock. A similar conductive zone (Conductor B) is centred approximately 2 kilometres northwest of the Talisker corridor and parallel to it.

Highlights from Brixton's 2011 program include hole THN11-60 at the Oban Breccia Zone which returned 95.08 metres of 628.3 grams per tonne silver, 1.71 grams per tonne gold, 0.12 per cent copper, 3.31 per cent lead and 2.39 per cent zinc including 9.25 metres averaging 2,984.4 grams per tonne silver, 3.04 grams per tonne gold, 0.53 per cent copper, 11.60 per cent lead and 3.42 per cent zinc. The 2011 program consisted of 21 holes (5,682 metres) which tested multiple targets over a 1900 by 1750 metre area (http://www.kiskametals.com/s/Thorn.asp).

The 2012 program focused on the gold-silver-copper-lead-zinc Oban Breccia Zone to follow up 2011 drilling. A total of 2,889.67 metres were drilled in 26 NQ core holes. The depth of the holes ranged from 30 metres to 153 metres. Consistent with previous drilling, mineralization is comprised of pyrite, galena, sphalerite, sulphosalts and chalcopyrite hosted in a hydrothermal breccia matrix. The breccia that hosts Oban mineralization is thought to be at least 300 metres in diameter with its eastern extent buried under glacial till (Kiska Metals Corporation News Release September 4, 2012). Three hundred and sixty two soil and talus samples were collected from the Amarillo creek area. Mapping alteration minerals using Multi-spectral ASTER data was acquired and analyzed in 2012 over the Thorn project.

In 2020, Brixton Metals Corporation completed a program of geochemical (rock and soil) sampling, a 12.5 line-kilometre ground induced polarization survey, a 715 line-kilometre airborne magnetic and electromagnetic survey and 19 diamond drill holes, totalling 5292 metres, on the area of as part of the Thorn property. Drilling was performed on the Outlaw (MINFILE 104K 176) occurrence area.

See also Drill Creek (MINFILE 104K 018), Talisker (MINFILE 104K 133), Cragganmore (MINFILE 104K 132) and Camp Creek (MINFILE 104K 116).