The property area is within the Precambrian-Paleozoic(?) Monashee Complex (Group) near the eastern edge of the Shuswap Metamorphic Complex, and underlain by a sequence of quartzite, calcsilicate and pelitic gneiss, marble and amphibolite that trends generally northward and dips at various angles to the east. A pronounced foliation, essentially parallel to layering, suggests that the apparently simple homoclinal sequence that hosts the mineral occurrence is, in fact, part of a complex, isoclinally folded metasedimentary package.
Mineralization at the Sherpa occurrence includes disseminated to massive pyrrhotite and sphalerite with minor amounts of pyrite and galena in a generally impure calcareous quartzite unit within pure to siliceous marble. The unit trends northeastward and dips moderately steeply to the southeast into the hillside; its exposed length is in excess of 500 metres.
Diamond drilling intersected a mineralized interval that ranges in thickness from 17 to 27 metres. It is dominated by calcareous to relatively pure quartzite with thin interlayers of unmineralized marble, quartzite and gneiss. Mineralization consists dominantly of rounded, disseminated grains and irregular blebs of pyrrhotite and sphalerite in a medium grained diopside-phlogopite quartzite and also of highly irregular, composite grains interstitial to the quartz grains. Locally, pyrite forms rounded, composite grains within massive pyrrhotite, and galena occurs in trace amounts. As well, pyrrhotite and sphalerite are disseminated in coarse, granular marble units that are within or along the edge of mineralized quartzite layers. Total sulphide content in both quartzite and marble ranges from trace amounts to 30 to 40 per cent. Highest assay values across variable widths from the mineralized intervals were 4.26 per cent zinc, 0.18 per cent lead, 4.6 grams per tonne silver and 0.41 gram per tonne gold (Assessment Report 13727).
Drilling also cored rare sillimanite garnet gneiss, sillimanite gneiss, quartz feldspar gneiss, graphitic quartz feldspar gneiss and biotite quartz feldspar gneiss.
