The area is underlain by the Lower Cambrian part of the Eagle Bay Formation consisting of siliceous and graphitic phyllites, phyllitic limestone and greenschist. The metavolcanics and meta- sediments generally strike northeast and dip 10 to 40 degrees north- west. The rocks are cut by Late Cretaceous or Early Tertiary quartz- feldspar porphyry and mafic dykes with northerly trends.

Mineralization comprises sulphides of silver, lead and zinc within metasedimentary rocks on the north limb of the Nitwikwaia synform. The showings occur within a dominantly metasedimentary succession (EBGs) of siliceous and/or graphitic phyllite, calcareous phyllite, streaky banded calc-silicate rock, limestone and quartzite. The metasediments are stratigraphically underlain by chloritic schists and greenstone (EBG). (Preto, et al in preparation).

The Big Ben showing, 500 metres south of Lucky Coon (082M 012), is underlain by graphitic and chloritic phyllites cut by several rhyolite dykes.

Mineralization, consisting of galena, sphalerite and chalco- pyrite, occurs along a shear zone within quartz veins measuring 2.5 to 56 centimetres in width. The shear zone, 15 metres long and 30 centimetres wide strikes northeast and dips 65 degrees west.