The Mark occurrence is located on a small creek flowing into the south eastern corner of Fair Harbour. This lies 1.0 kilometre east of the Mica quartz-sericite occurrence (MINFILE 092L 277).

The region of the Mark occurrence lies within northwest striking Lower Jurassic Bonanza Group volcanic rocks, intruded several kilometres to the south and east by the Amai and Zeballos intrusions respectively. The intrusions range from quartz-diorite to quartz- feldspar porphyry and belong to the Jurassic Island Plutonic Suite.

Mineralization consists of sparsely disseminated chalcopyrite in dark crystal tuffs that exhibit strong epidote, chlorite and calcite alteration near a granodiorite intrusion. Boulders containing coarse clots of chalcopyrite and bornite within irregular K-feldspar-quartz stock-work are also reported.

In 1980, the area was explored as the Mica property by J.T. Shearer.