The North vein occurrence is located at an elevation of approximately 1400 metres on a north-northeast–facing slope, southwest of the Toodoggone River and approximately 2.8 kilometres west of the river’s 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 North vein occurs in outcrop and subcrop, largely as loose material (blocks up to 1.5 metres) of porphyritic andesite of the Lower to Middle Jurassic Hazelton Group, and is reported to be a low-sulphidation–style, sugary quartz vein located along a 250-metre trend.
Another area of mineralization, located approximately 150 metres upslope to the south-southeast, is exposed in subcrop and contains carbonate with base-metal values but low gold values. The veins at this location are up to 0.6 metre wide and mineralized with pyrite, galena and minor sphalerite. The silica has poorly developed chalcedonic banding.
In 2005, assay values from the vein range up to 25.8 grams per tonne gold and 234 grams per tonne silver across 0.7 metre from the furthest southeast sample of the vein before it is covered by talus, whereas four other samples, taken along the vein, averaged 12.77 grams per tonne gold and 179.2 grams per tonne silver (Assessment Report 28038).
In 2006, a sample of the subcrop mineralization yielded 2.6 grams per tonne silver, 0.980 per cent lead and 0.624 per cent zinc (Assessment Report 28647).
Work History
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 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 was included 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. This survey outlined an 800-metre wide by 1200-metre long +40 millisecond induced polarization chargeability anomaly that was open to the north.
In 2006, Stealth Minerals further expanded the IP/ground magnetic survey by another 21 line-kilometres and expanded the chargeability anomaly a further 600 metres north and 300 metres west. During the 2006 season, a total of 28 rock samples were taken from outcrop and float. Geophysical surveys were completed in the area between and covering the Sofia (MINFILE 094E 238) to Quartz Lake (MINFILE 094E 301) occurrences.
In 2015, a program of geophysical review completed for Cazador Resources Ltd. on the Sofia property identified five target areas. Later that year, a 4.0 line-kilometre induced polarization survey was completed.
In 2017, Cazador Resources completed 239.0 line-kilometres of airborne magnetic surveying and a 2.5 line-kilometre ground induced polarization survey on the Sofia property.
See Sickle Creek (MINFILE 094E 237) occurrence for further details of the Stealth Minerals Limited Sickle-Sophia property.
