The Adda occurrence is situated on the west side of the northwest arm of Takla Lake, approximately 29 kilometres south of Takla Landing.

The area is underlain by andesitic to basaltic volcanics and minor sediments assigned to the Lower Jurassic undivided Telkwa/Nilkitkwa formations of the Upper Triassic-Middle Jurassic Hazelton Group, west of a large pluton of the Late Triassic-Early Jurassic Topley intrusions. The north-striking Takla fault separates the Hazelton Group rocks from Cretaceous sediments to the west.

A few veins of chalcopyrite, 5 to 7.6 centimetres in width, and some narrow calcite seams were observed in andesite just above the lakeshore. Selected portions of the chalcopyrite assayed 5.49 grams per tonne silver and 10.6 per cent copper, with trace gold (Minister of Mines Annual Report 1930, page 149).

No recent information concerning this occurrence is available.