The area is underlain by rocks of the Cambrian to Ordovician part of the Eagle Bay Formation consisting of limestone, argilla- ceous limestone, greenstone schist, quartz sericite schist, quartz- ite and phyllite.

Replacement zones of mineralization occur within the meta- volcanics and metasediments. The minerals include sphalerite, galena, pyrrhotite, arsenopyrite, chalcopyrite, tetrahedrite and argentite with minor quartz, epidote, chlorite, calcite and mica.