The Steep property is located on the west side of Adams Lake, approximately 55 kilometres northeast of Kamloops.
The regional geology is described by Okulitch (1979) (Geological Survey of Canada Open File 637), and by Schiarizza and Preto (Preliminary Map 65, Paper 1987-2). The mineralization is hosted by northeast-dipping argillaceous limestones and black calcareous phyllites of the Sicamous Formation, close to their contact with the structurally overlying Eagle Bay assemblage. The Sicamous Formation was assigned a Late Triassic age by Okulitch (1979), but is now though to be of Paleozoic age (Okulitch, 1985). It is inferred to be a facies equivalent of part of the Early Cambrian to Mississippian Eagle Bay assemblage (Schiarizza and Preto, 1984, 1987). Eagle Bay rocks, which sit structurally above the Sicamous Formation in the vicinity of the Steep property, comprise Devonian felsic metavolcanics and associated metasediments together with Devonian orthogneiss presumed to be comagmatic with the metavolcanics. Quartz porphyry schists which occur locally within the skarn-altered Sicamous Formation are thought by Schiarizza and Preto (1987) to be feeder sills related to the overlying metavolcanic rocks.
Pyrrhotite average 5 per cent and is the dominant sulphide. Layers of massive pyrrhotite and minor magnetite occur together locally. Other sulphides include pyrite, chalcopyrite and rare sphalerite and galena which may form fine intergrowths with the pyrrhotite. Miller et al (1988) reports that the gold forms minute grains, 5 to 15 microns in diameter, which generally occurs with the pyrrhotite. The gold is also associated with minute grains of native bismuth and bismuth tellurides. Mineralization tends to be found close to the outer margin of the skarn zone.
Soil sampling suggests that the areas of higher gold values coincide with anomalous values of arsenic and copper, and to a lesser extent with lead and zinc. The best drillhole intersection recorded 3 metres of 5.8 grams per tonne gold. However maximum assay values for other elements were 22 grams per tonne silver, 2000 parts per million arsenic, 272 parts per million bismuth, 3830 parts per million copper, 6910 parts per million lead, 1.5 per cent zinc and 173 parts per million antimony (Miller et al, 1988). A visual examination of the assay results suggests that gold has a relatively poor correlation with silver, arsenic, antimony and lead but a strong positive correlation with bismuth. Copper, lead, zinc, arsenic and antimony all exhibit a good positive correlation with each other.
The age and origin of the Steep property mineralization is unknown, and it is uncertain whether it represents an intrusion-related, epigenitic skarn, or a syngenetic, exhalitive "stratiform skarn" deposit.
Recent exploration work on the property, including some diamond drilling, has been conducted by National Resources Explorations Limited, and a summary of the skarn mineralization and geochemistry has been presented by Miller et al (1988). A concordant zone of skarn alteration that reaches several hundred metres in width is traceable for a least 10 kilometres along strike. It includes calc-silicate and garnet-rich skarn; the former is up to 80 metres thick, and mainly comprises fine-grained amphibole, plagioclase, and epidote with lesser amounts of biotite, sphene, chlorite, apatite, plagioclase and potassium feldspar. Minor amounts of pyroxene have been identified in thin section although it is mainly altered to chlorite and epidote (D. Miller, personal communication, 1989). A complete exploration history can be found in Assessment Report 32427.
