The D11 occurrence is located on the northeastern slopes of Mount Flannigan at an elevation of approximately 1,220 metres.

The area is underlain by basaltic volcanic rocks of the Upper Triassic Karmutsen Formation (Vancouver Group). These have been intruded by granodioritic intrusives of the Jurassic Island Plutonic Suite to the east.

Locally, quartz-bornite veins with epidote-chlorite alteration are hosted in shallow north- dipping basaltic agglomerates and massive flows. Mineralization is in the form of 1 to 2 centimetre thick, discrete veins, widely spaced and traceable for a few meters in logging road outcrops. The vein filling is largely massive bornite inter-veined with white quartz, but varies to bornite and or chalcocite dispersed in white quartz and some carbonate. Malachite forms 2 millimetre crystalline masses replacing the bornite in the more dispersed style of vein filling and also botriodal crusts on more massive bornite. The bornite comprises up to 50 per cent of the vein filling.

In 2011, select grab samples yielded up to 20.76 per cent copper and 40.1 grams per tonne silver (sample D11-1; Assessment Report 32897).

In 1996, high-grade copper-bearing float, assaying 13.8 per cent copper and 16 grams per tonne silver, was found in the area by W. Crombie (Assessment Report 30383). In 2007, the area was staked as the Dass claim and prospected through 2011.