The area of the Griz showing is underlain by stocks, dikes and sills of quartz monzonite and quartz-feldspar porphyry of the Paleocene to Eocene Sloko-Hyder Plutonic Suite which have intruded Lower Jurassic sediments of the Takwahoni Formation, Laberge Group and volcanic rock of the Upper Triassic Stuhini Group. Both effusive and hypabyssal varieties of the feldspar porphyry are present. The rock varies from pink to green in colour, aphanitic to medium-grained, containing feldspar phenocrysts of varying sizes. Minor disseminated pyrite is common. Small quartz veins, commonly drusy and up to 1 centimetre wide cut the porphyry. Larger quartz veins also crosscut the porphyry. In 1981, petrographic analyses of the porphyry classified it as tracyandesitic in composition. A large north-northwest trending fault forms the southern contact between the porphyry and the Takwahoni sedimentary unit.
Several occurrences of galena and sphalerite are found within crosscutting quartz veins within the porphyry. On the southeast side of a main valley which cuts the claims, galena mineralization occurs in small blebs, ranging from 1 to 5 millimetres in size, within highly silicified feldspar porphyry host rock. The silica is almost black in the well mineralized areas. Rusty, calcite-sphalerite veins, quartz veinlets and manganese staining are also associated with the mineralization. Veinlets of galena and sphalerite, up to 8 millimetres in width, were also found on the northwest bank of the main valley. Abundant pyritic and silicified zones and calcite veins are associated with the mineralization. In the southern part of the property pyritic quartz breccia and pyritic seams occur within the porphyry.
In 1981, several chip samples were collected from trenches. Two chip samples from Trench 1 in silicified porphyry assayed 4.73 grams per tonne gold, 1.03 grams per tonne silver, and 1.3 grams per tonne gold, 1.71 grams per tonne silver, respectively (Assessment Report 9824, part 1). Chip samples from galena-sphalerite-calcite veins and lenses in Trenches 2 and 4 assayed 0.1 gram per tonne gold, 76.46 grams per tonne silver, 1.78 per cent lead, 3.05 per cent zinc, and less than 0.1 gram per tonne gold, 115.88 grams per tonne silver, 0.48 per cent lead, 0.77 per cent zinc respectively (Assessment Report 9824, part 1). The gold values do not appear to be associated with the galena-sphalerite mineralization but with the highly silicified feldspar-porphyry and with rusty breccia fragments of feldspar porphyry.
WORK HISTORY
The area was first staked in 1981 as the Griz 1-3 by Newex Syndicate with prospecting, mapping soil sampling and trenching completed in the same year. Four trenches were excavated and mapped in 1981 on the Griz 1 and total of 9 chip samples and 62 soil/talus samples were collected.
In 1991, Omega Gold Corporation conducted a geochemical sampling program consisting of 79 rock samples, 47 soil samples and 7 silts on their A 1-8 claims which covered the Griz (104K 073), Griz 3 (104K 114) and Emu (104K 115) occurrences. Two soil lines were established, with one oriented to test the downslope extent of the Griz 1 showing. The other line was laid out perpendicular to the structural trend on the property (over 3.5 kilometres northwest of the Griz) to evaluate the geological contacts and the major northwest trending fault zone. In the area of the Griz showing a maximum value of 1.27 grams per tonne gold was obtained (Assessment Report 21908). This sample consisted of a sheared, brecciated, and silicified feldspar porphyry with iron carbonate alteration and containing 5 per cent pyrite.
In 2016 to 2019, Brixton Metals Corporation expanded their Thorn property through staking and acquisition of claims including those covering all the Griz (104K 073), Tardis (104K 112), Griz 3 (104K 114) and Emu (104K 115) showings. Refer to Thorn (104K 031), Chivas (104K 180), East Outlaw (104K 083), Oban (104K 168), Trapper (Inlaw) (104K 078) and Metla (104K 161) for details of the work history of the greater Thorn property.
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.
As of early 2021, no work had been done on the Griz (104K 073), Griz 3 (104K 114) and Emu (104K 115) since 1991 and the Tardis (104K 112) since 1987.