The Iron Duke occurrence is located on the south side of Elsul Creek, a tributary of Tranquil Creek, at an elevation of approximately 620 metres.

Diorite to quartz-diorite of the Early to Middle Jurassic Island Plutonic Suite or the pre-Jurassic Westcoast Complex intrude Paleozoic Sicker Group volcanics and Buttle Lake Group sediments. Magnetite- copper skarns and veins located along the igneous/volcanic contact, are localized by calcareous sediments and limestone, which likely belong to the Upper Pennsylvanian to Lower Permian Mount Mark Formation (Buttle Lake Group). The volcanics include porphyritic andesite.

The Iron Duke showing occurs along a north west trending, 70 degree south east dipping contact between diorite and limestone. A skarn containing chalcopyrite and magnetite, with garnet and epidote, occurs in limestone. An average sample taken assayed 2.0 per cent copper and 13.7 grams per tonne silver (Minister of Mines Annual Report, 1916-331).

In 1985 and 1987, West-Mar Resources Ltd. completed programs of rock, silt and soil sampling on the area. In 1991, the area was prospected by K.E. Hicks.