The Silver Tusk occurrence is located on a south flowing tributary of Red Tusk Creek, at an approximate elevation of 900 metres. The area has been explored in conjunction with the nearby Red Tusk Discovery (MINFILE 092GNW051), South, North and North Extension occurrences.
The area occurs in the Clowhom pendant, an elongate pendant of Lower Cretaceous Gambier Group volcanic and sedimentary rocks. The pendant is surrounded by quartz diorite/diorite of the Cenozoic-Mesozoic Coast Plutonic Complex and appears to have undergone local hornfelsing, folding and faulting.
The occurrence is underlain by a series of marine sediments and volcanics in a relatively undisturbed sequence of north to northwest-trending and moderately to steeply west-dipping units. Stratigraphic tops also face west. The sedimentary units are composed of cherts and argillites and do not constitute a large portion of the stratigraphy volumetrically, but are important as marker horizons. The cherts are generally massive but occasionally are well laminated. The argillites are frequently hornfelsed, uniformly fine-grained, black pyritic rocks, occasionally containing narrow (10 centimetres or less) beds of semi-massive pyrite/pyrrhotite and rarely sphalerite. The dominant pendant rocks are andesites and include agglomerates, flows and tuffs. The intrusive rocks are diorite to quartz diorite in composition with minor differentiated zones of granodiorite and gabbro.
The volcanic rocks are variable in composition and include basalts, dacites, rhyodacites, rhyolites, massive andesite porphyries and laminated tuffs, and a distinctive fragmental unit. Late mafic dikes cut the stratified sequence and usually strike northeast and dip vertically. Some folding is evident and faulting is randomly distributed, with little or no movement. An altered siliceous horizon trends north across the property and is comprised of a light grey to grey massive, aphanitic, siliceous, rhyolitic unit with a characteristic chalky white weathering. Prominent foliation and shearing accompanied by quartz veining is present along the entire length of the unit.
Intermediate to felsic volcanics occupy the central portion of the property. The rocks are dacite to rhyodacite in composition and include flows, gritty lapilli tuffs and finely laminated ash tuffs. A fragmental volcanic rock unit (polymictic volcanic breccia) occurs and is composed of crowded, angular to sub-angular, mixed pebble to cobble sized clasts of tuffs, flows, chert and argillite in a fine-grained, dusty matrix. This unit generally overlies two thin units of andesite agglomerate and tuff, which in turn overlie andesite flows.
Locally, a mineralized quartz-carbonate vein, measuring up to 18 metres wide and striking 15 degrees west with a dip of 70 degrees south west, is hosted in a fault contact zone between chloritized diorite of the Coast Plutonic Complex and hornfelsed tuffaceous andesite of the Gambier Group. A wide band of sericite schist forms on the east footwall next to the andesite and contains disseminated sulphides.
Mineralization is concentrated towards the center of the vein and consists of galena, sphalerite and pyrite occurring as small veins and pods accompanied by secondary quartz, feldspar, chlorite and epidote. Small quartz veins hosting pyrite cut both the diorite and andesite for a short distance.
In 1981, a select grab sample (3) assayed 2.7 grams per tonne gold, 363.6 grams per tonne silver, 5.5 per cent lead, 4.7 per cent zinc, 0.03 per cent copper, 0.07 per cent antimony and 0.02 per cent cadmium,; while a 3.0 metre combined chip-grab sample (4) assayed 17.2 grams per tonne silver, 0.25 per cent lead, 0.50 per cent zinc, 0.08 per cent copper and 0.015 per cent molybdenum (Assessment Report 10279).
In 1982, a grab sample (20230A) assayed 0.185 per cent copper, 0.370 per cent lead, 1.0 per cent zinc, 62.0 grams per tonne silver and 3.3 grams per tonne gold (Assessment Report 11180).
In 1981 and early 1982, the area was prospected and sampled as the Silver Tusk claims. During late 1982 through 1985, Newmont Exploration of Canada completed programs of geological mapping, rock, silt and soil sampling and 12 diamond drill holes, totalling 647.7 metres, on the area as the Red Tusk property. In 1988, Schellex Gold completed a program of prospecting, rock sampling and trenching on the area. In 1995 and 2000, limited programs of heavy mineral stream sediment sampling were completed. In 2003, Red Tusk Resources, on the behalf of Gambier Mining, completed a program of geological mapping and rock, silt and soil sampling. In 2005, the area was prospected as the Iota claim. In 2009, a petrographic analysis was completed on samples collected in 2005.
