The Good Friday Crown Grant is underlain by siltstone, argill- ite and hornfels, and breccia complex of the Pennsylvanian and poss- ibly Permian Mount Roberts Formation. The succession is thought to have been thrust over augite porphyry of the underlying Rossland sill of the Elise Formation (Rossland Group) prior to the intrusion of the Middle to Late Jurassic Trail pluton (Nelson Intrusions). The silt- stone is also intruded by the Early Jurassic Rossland monzonite and monzonite breccia as well as by the syenitic Middle Eocene Coryell Intrusions and associated syenite dykes. Lenticular masses of andes- ite and late, steeply dipping, north-trending lamprophyre and diorite dykes have also invaded the siltstone.

By 1915, an adit had been driven on a wide band of mineralized agglomerate similar to that on the Coxey claim (082FSW110). The band strikes southwest, in the direction of the Jumbo mine (082FSW111), and contains pyrite, galena and sphalerite. Outcrops of diorite porphyrite, thought to be a marginal facies of the Rossland monzonite, occur in the area.

The Northern Belle claim, situated east and adjacent to the Good Friday claim, contains two east-striking veins and a third one which cuts the first two at right angles. The latter had been opened up between the east-striking veins but the type of mineralization was not reported.