The Blue showing is underlain by andesitic volcanic rocks of the Unuk River Formation, Hazelton Group. Contact with granodiorite of the Early Jurassic Texas Creek Plutonic Suite occurs to the immediate west.

The showing occurs near the contact of graphitic argillite and overlying andesitic tuff. A 1.2-metre-wide rusty fault zone occurs within the argillite and is oriented at 163 degrees strike and 70 degrees dip southwest. A 1-metre-wide fine-grained diorite dike occurs along the argillite-andesite contact.

Mineralization is associated with a 1-metre-wide silicified zone in the argillite which contains quartz veins up to 5 centimetres wide. This zone parallels the fault. Within the quartz vein are pyrite (5 per cent), sphalerite (2 per cent), galena and arsenopyrite. Sample 30338 which represents this silicified and quartz-veined argillite assayed 0.024 per cent copper, 0.064 per cent lead, 0.96 per cent zinc, 8.0 grams per tonne silver and 0.24 gram per tonne gold (Assessment Report 19294). Pods of massive pyrite with 5 per cent black sphalerite also occur within the silicified zone. These pods are at least 5 by 30 centimetres.

The Blue showing was first reported by Homestake Mining in 1989 (Assessment Report 19294). Westmin examined the area from 1990 to 1992 but does not report on this showing. See Extreme (MINFILE 104B 475) for further details.