The area is underlain by metamorphic rock of the Mesozoic and/or Paleozoic Wark Gneiss and greenstone of the Lower Jurassic Bonanza Group. A discontinuous limestone horizon extends along a northwest trend and is thought to be correlative with the Upper Triassic Quatsino Formation, Vancouver Group. The Wark Gneiss comprises mainly massive and gneissic metadiorite, metagabbro and amphibolite (see Willoron 1-3,9,10 - 092B 056). The Wark Gneiss is possibly the metamorphic equivalent of a mafic unit of the Paleozoic Sicker Group, the latest metamorphism having taken place in the Jurassic.

Numerous magnetite showings occur in the area as lenses and fracture-fillings in all rock types, but mainly in association with limestone lenses. Associated skarn minerals are reported to be garnet, epidote and diopside.

On the Willoron 6 showing (Showing 13), massive magnetite occurs overlying skarn having a steep southward dip. About 30 metres to the south, magnetite is exposed and is overlain by skarn. It is thought that the intervening distance between the showings is underlain by magnetite. Minor pyrite and pyrrhotite are associated with the magnetite. A 1.5-metre channel sample across one of the exposures graded 66.5 per cent iron, 0.43 per cent sulphur and a trace of phosphorous (Aho, 1961, page 13).

The magnetite outcrop is reported to lie at the base of a slope with greenstone outcrops to the northeast and diorite outcrops on the other side to the west. About 50 metres to the west of the magnetite outcrop are exposures of alaskite, greenstone, limestone and minor skarn with a few inches of magnetite.