The area of the Marcasite Gossan occurrence is underlain by Middle Jurassic rocks of the Hazelton Group.

Mapping of the mafic package above the Marcasite and South gossans shows a package of alternating pillow basalt and basalt breccia. The breccias consist of bomb tuffs and rubble breccias overlain by mafic crystal tuff. About 70 metres of elastic sediments, including graphitic argillite with semimassive pyrite beds, lies between the Upper Marcasite Gossan and the “hanging wall” pillow basalt. An altered felsite sill, chemically identical to the Eskay Rhyolite, intrudes these clastics, which are at a stratigraphic position equivalent to the Eskay Creek stratiform orebodies.

Two holes were drilled at the Marcasite Gossan showing in 2004. Neither hole at the Marcasite Gossan yielded any geochemical results of significance. Anomalous mercury is associated with sulphidic sections and locally, crackle brecciated and veined sections containing sparse blebs of sphalerite along with disseminated pyrite return weakly anomalous silver, lead and zinc values in both holes.

Similarly, no significant assays resulted from 2 holes drilled on the zone in 1999.

Refer to RDN (104G 144) for details of a common work history.