The area is underlain by two Upper Triassic Vancouver Group formations consisting of Karmutsen volcanic rocks overlain on their north-eastern margin by a northwest trending belt of Quatsino limestone, known historically as the "lime-belt". These are in fault and/or intrusive contact to the northeast with Jurassic to Tertiary intrusive rocks of the Coast Plutonic Complex.

The Anaconda occurrence is probably located along the lower half of Stramberg Lake's western shore about 180 metres southwest of the intrusive contact.

A fractured mineralized zone, 4 to 6 metres in width, occurs along the contact between limestone and finely textured, greenish andesitic rocks, the contact having a general strike of about 125 degrees. Throughout this zone, the volcanic rocks are much altered and iron-stained, and include, in places, some disseminated pyrrho- tite, pyrite, chalcopyrite, garnet, epidote and other silicates. Quartz also occurs within this zone, either irregularly distributed or in the form of narrow veinlets up to 15 to 20 centimetres in thickness, the quartz of the veinlets being characterized by long, interlacing, interlocking crystals (Geological Survey of Canada Summary Report 1913, page 74-75).

A 0.6 metre sample of pyritic matter taken along the limestone- andesite contact assayed 6.86 grams per tonne gold and 6.86 grams per tonne silver (Minister of Mines Annual Report 1913, pages 284-286).