The Sulphurets map area lies along the western margin of the Intermontane Tectonic Belt and lies within Stikinia Terrane. The area is underlain by Lower Jurassic Unuk River Formation, Hazelton Group, volcanic and sedimentary rocks that have been folded, faulted and weakly metamorphosed, mainly during Cretaceous time. Strata are cut by at least three intrusive episodes.

The Kerr Copper mineral occurrence is reported to lie entirely within a "tectonic shear zone". This zone contains all the signifi- cant gold anomalies. The zone covers an elongate northern trending area, 800 to 900 metres wide and two kilometres long. The zone is flanked by comparatively unaltered or weakly altered, fine-grained, brownish green clastic sediments and submarine volcanics on the east, and by a thick unit of basaltic andesite on the west. The tectonic zone is typically composed of moderately to strongly altered and sheared rocks interpreted to be of volcanic, subvolcanic, or plutonic origin. Most of the altered zone can be described as a sericite schist, however andesitic tuffs and flows, feldspar porphyry dykes and possibly flows can be recognized in less altered zones. A later formed "swarm" of fine-grained weakly altered andesite dykes cut across the schistosity. Both the altered zone and dykes have been cut by faults. Minor sections of silty shale and siltstone occur on the western and eastern margin of the altered zone.

Rock types within the D zone are likely andesitic tuffs altered to sericite schist. Within the sheared zones quartz and/or pyrite veins occur and strike in a west to northwest direction. One 4 metre wide pyrite vein occurs in one such shear zone.

The D zone is located within the same fault-bounded block as the A zone (104B 194). The West Fault marks the western boundary, the A zone Fault marks the eastern boundary.

The D zone is one of the soil geochemical anomalies outlined in September 1985. Results of more detailed follow-up work in 1986 were not encouraging. Most rock chip samples contained between 0.1 and 0.5 grams per tonne gold with only one greater than 0.5 grams per tonne gold (0.85 grams per tonne) (Assessment Report 15493). Some trenching has been completed on nearby mineralized outcrops. No work was carried out here in 1987 or 1988.