The area of the Silica Cap zone is underlain by the contact of a quartz dioritic intrusion of the Late Cretaceous Wind Table Complex with intermediate (andesitic) volcanics of the Lower Jurassic Takwahoni Formation (Laberge Group).

The Silica Cap zone was identified in 1982 and is found to the southwest of the Slope zone along the lower reaches of Copper and Moly creeks (Assessment Report 21687, Figure 3). This zone has been considered to represent a high temperature skarn feature by virtue of characteristic alteration mineralogy of: silica, actinolite, epidote, garnet, pyrite, magnetite, tourmaline, and pyrrhotite, plus sulphides of chalcopyrite, galena, sphalerite, molybdenum and arsenic. Samples were anomalous for gold and strongly anomalous in silver. The highest value from a rock sample taken from a broken quartz-copper-lead-zinc-molybdenum vein in the Moly Creek shear, was 16.55 grams per tonne gold and 214.5 grams per tonne silver (Assessment Report 18803, Figure 4). Davis and Jamieson (Assessment Report 25970) suggest that the presence of a silica cap on the property would indicate that a late-staged epithermal gold system may have overprinted porphyry mineralization once the intrusion had been unroofed by erosion.

The Slope (104K 010), Ridge (104K 085) and East Cirque zones are considered by Wilkins and MacKinnon (Assessment Report 18803) to be part of one large porphyry system with the Slope representing the stockwork and sheeted vein-hosted copper and molybdenum mineralized core. The Ridge and East Cirque zones to the northeast of the Slope and possibly “Moly and Copper creeks” (Silica Cap) to the southwest may represent structurally controlled conduits for sulphide bearing hydrothermal solutions.

Please refer to the Slope occurrence (104K 010) for details of the area geology and a common work history.