The Calder occurrence is located in a roof pendant of Lower Cretaceous Gambier Group rhyolite and dacite flows, 200 metres east of the contact with diorite and tonalite of the Jurassic to Tertiary Coast Plutonic Complex. The volcanic rocks strike 350 degrees and dip 80 to 85 degrees east.

Mineralization has been observed over a 4.0 metre wide zone in thin veinlets and pods that range from 1.5 to 8.0 millimetres in width, and consist of chalcopyrite and sphalerite with associated silver values. The veinlets parallel bedding attitudes. A few metres north of the trench that exposed this mineralization, no mineralization is present, while 15 metres to the south only a single veinlet is reported. A grab sample from the trench assayed 19.2 per cent copper, 2.63 per cent zinc and 88.81 grams per tonne silver (Assessment Report 11230, following page 8).

Assessment Report 14272 (page 20) casts some doubt on the loca- tion of the trench.