The Kevin occurrence is located at an elevation of approximately 1300 metres on a northeast-facing slope, southwest of the Toodoggone River and approximately 4.6 kilometres west-northwest of the rivers’ junction with Bronlund Creek.
Regionally, the area is situated within a Mesozoic volcanic arc assemblage, which lies along the eastern margin of the Intermontane Belt, a northwest-trending belt of Paleozoic to Paleogene sediments, volcanics and intrusions bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins.
Permian Asitka Group crystalline limestones are the oldest rocks exposed in the region. They are commonly in thrust contact with Upper Triassic Stuhini Group andesite flows and pyroclastic rocks, and marine sedimentary and volcanic rocks of the Lower to Middle Jurassic Hazelton Group. These rocks have been intruded by plutons and other bodies of the mainly granodiorite to quartz monzonite Early Jurassic Black Lake Suite and are in turn unconformably overlain by or faulted against Lower Jurassic calc-alkaline volcanics of the Toodoggone Formation (Hazelton Group).
The dominant structures in the area are steeply dipping faults that define a prominent regional northwest structural fabric trending 140 to 170 degrees. In turn, high-angle, northeast-striking faults (approximately 060 degrees) appear to truncate and displace northwest-striking faults. Collectively these faults form a boundary for variably rotated and tilted blocks underlain by monoclinal strata.
The occurrence area is underlain by reasonably undivided volcanics of the Hazelton Group. On a property scale, four units have been delineated from the volcanic stratigraphy. These consist of light-grey to green plagioclase and hornblende plagioclase tuffs and breccias; grey-green, orange and brown, fine to coarse-grained plagioclase porphyry, including minor quartz-eye porphyry; felsic tuffs and breccias; and thin-bedded, well-cleaved rhyolite. Indications are that this stratigraphy is continuous with the Toodoggone Formation rocks immediately to the west. These rocks have been intruded by three varieties of plutonic rocks: syenite to syenodiorite, granodiorite and quartz diorite, that has been subject to moderate to intense kaolinite and pyrite alteration (up to 40 per cent) and silicification. The silicification is commonly so intense that all primary textures are obliterated. Three major fault systems intersect just north of the occurrence.
Locally, two zones of silicification and pyrite alteration are hosted in granodiorite. The zones trend between 160 and 175 degrees and contain between 25 and 40 per cent pyrite with lesser sphalerite and galena. A 1-centimetre wide chalcopyrite vein is also reported in the area. The altered and mineralized zones are considerably more foliated than the host granodiorite.
Another zone of mineralization, located approximately 450 metres south of the main zone at an elevation of 1500metres, comprises a silicified zone with pyrite occurring at the contact between feldspar porphyry and feldspar breccia.
In 1986, two 1-metre long chip samples (JS-86-P2001 and JS-86-P2002) from the main zone yielded 4.9 and 10.1 grams per tonne silver with 0.09 and 0.14 per cent barium, respectively (Assessment Report 15599). Also at this time a sample (JS-86-P2005) from the southern zone analyzed 4.5 grams per tonne silver (Assessment Report 15599).
In 2004, a rock sample (148565) of a 1-centimetre wide chalcopyrite vein assayed 0.09 gram per tonne gold, 39.4 grams per tonne silver and greater than 1.00 per cent copper and zinc, respectively, whereas float samples from the area yielded up to 0.88 gram per tonne gold and 47.4 grams per tonne silver (Assessment Report 27790).
Work History
In February 1986, an airborne VLF-EM and magnetometer survey was flown over the claims by Western Geophysical Aero Data Ltd. on behalf of Peralto Resources Corp. The close association of magnetometer highs and lows was interpreted as fault related.
In October, 1986, Hi-Tec Resource Management Ltd., on behalf of Peralto Resources, carried out a program of soil, rock, and silt sampling; geological mapping; prospecting and a ground geophysical survey on the Bishop, Castle, Kevin and Knight claims. They collected 89 rock, 30 silt and 522 soil samples and conducted an 8.5-kilometre ground VLF survey and a 6.2-kilometre magnetic survey. Several zones of silicification and pyritization were identified on the property. Geochemical and geophysical surveys have delineated a northwest-trending structure with zones of secondary silicification and faulting.
In 1988, Peralto Resources Corp. completed a geochemical sampling program, primarily on the Bishop and Knight claims. The work consisted of two contour soil sampling lines at approximately 1700 and 1900 metres above sea level, one downhill soil traverse, one silt sampling line and rock sampling. A total of 58 rock chip and grab samples were collected.
In 1999, Stealth Minerals staked the initial claims in the area of what is now known as the Sickle-Sofia property and, later that year Standard Metals conducted a small-scale geochemical program on the area on the behalf of Stealth Minerals.
In 2003, Stealth Minerals completed a program of rock, silt and soil sampling and 78.4 line-kilometres of ground geophysical surveys on the Pine property. Also at this time, as part of a private-public partnership with the Geological Survey of Canada and the British Columbia Department of Mines and Energy, the Sickle-Sofia property inlcluded in a multi-parameter helicopter-borne geophysical survey over the Toodoggone district. Several high potassium anomalies and low thorium-potassium ratio anomalies were detected.
In 2004, Stealth Minerals expanded the Sickle Sofia property package by staking additional claims. A grid-based soil survey was conducted over 27 square kilometres and a total of 728 rock and 2103 soil samples were collected.
In 2005, a program of geological mapping and a 21 line-kilometre induced polarization and ground magnetic geophysical survey was completed over the lower, glacial-fluvial–covered portion of the Sofia (MINFILE 094E 238) copper-gold porphyry target.
In 2006, Stealth Minerals completed further programs of rock sampling, geological mapping and ground geophysical surveys on the area.
In 2015, a program of geophysical review completed for Cazador Resources Ltd. on the Sofia property identified five target areas.
See Sickle Creek (MINFILE 094E 237) occurrence for further details of the Stealth Minerals Limited Sickle-Sophia property.
