The Blue occurrence consists of copper-molybdenum-silver mineralization in mountainous, glacier-covered terrain 25 kilometres south of the southern end of Tatlayoko Lake.

The Blue area is underlain by a foliated biotite granodioritic intrusion of the Late Cretaceous to Paleocene Bendor suite (no longer correlated with the Paleocene Tiedemann pluton) on the northeastern margin of the Jurassic to Tertiary Coast Plutonic Complex. Numerous, variably oriented dikes are widespread in the area, comprising lamprophyre, and less commonly felsite, aplite and pegmatite. Quartz veins are also abundant.

A narrow belt (varying from about 200 to 600 metres in width on surface) of the Late Triassic to Cretaceous Eastern Waddington thrust belt imbricate zone extends along surface some 10 kilometres from the Blue area to the northwest. The northeastern boundary of this belt is a formed by intrusive contact with the Bendor granodiorite, and the northwestern boundary is formed by a thrust fault which has placed tonalitic orthogneiss metamorphic rocks onto the imbricate zone rock to the northeast.

The Blue occurrence is centred on an area 600 by 300 metres, covering the Blue 33 to 36 claims, containing many mineralized quartz veins (Assessment Report 2669). The granodiorite is fractured and silicified and contains disseminated pyrite. Oxidation has produced zones of gossan. Molybdenite occurs in quartz-filled fractures up to 10 or 20 centimetres thick. Molybdenum values are not high, ranging from 0.001 to 0.05 per cent.

Other quartz veins contain bornite, chalcopyrite and locally molybdenite. A composite grab sample taken across a copper-rich zone 23 by 3 metres assayed 0.75 per cent copper and 6.8 grams per tonne silver. Another sample assayed 1.22 per cent copper (Assessment Report 2669).

Minor showings of molybdenite also occur 900 metres to the southwest, in the Blue 32 claim (Assessment Report 2669).

In 1970, geological mapping on the Blue prospect by Pacific Petroleum Ltd outlined an area of molybdenum mineralization some 600 metres by 300 metres. The mineralized area is estimated (not substantiated) to grade 0.02 per cent molybdenum sulphide (MoS2) (Assessment Report 2669). Geological mapping was done on scales of 1 inch to 1000 feet and 1 inch to 200 feet.