QuestEx’s 100% owned, 91 square kilometre (km), Sofia Property in the Toodoggone District of British Columbia, is strategically situated 35 km north of the historic Kemess mine and less than 20 km east of the historic Lawyers, Baker and Shasta mines (Figure 1). It occupies strategic and prospective ground in a district that is being actively explored by world class miners including Freeport McMoRan, Centerra, Hudbay Minerals and Hunter Dickinson (HDI), and numerous junior explorers including Benchmark Metals, TDG Gold Corp. and Evergold Corp.
Figure 1 Location of QuestEx’s 91 square kilometre Sofia property in the prolific Toodoggone mining district
The Toodoggone area is a mining and exploration district that is richly endowed with porphyry copper-gold and epithermal gold-silver mineral systems. Throughout the district, past producing mines and active exploration areas are concentrated along northwest to southeast oriented lineaments that are clearly demarcated on both geological and geophysical maps (Figure 2). The lineaments represent long-lived and deep penetrating fault systems that provided conduits for fertile magmas and hydrothermal fluids that formed the mineral systems. Sofia is located along one these prominent lineaments.
Figure 2 Prominent northwest-southeast lineaments on geological (left) and geophysical/magnetic (right) maps of the Toodoggone district. Mines and exploration projects are concentrated along the lineaments and the Sofia property is strategically located along one of the lineaments.
Despite the long history of exploration in the Toodoggone district, and the large number of mineral occurrences on the Sofia Property, there has been very little historical exploration on the property. QuestEx considers Sofia to be one of the most under-explored properties in the district, with great potential for discovery. The property is interpreted to contain the footprint of a large 6.5- by 4-kilometre hydrothermal system that spans at least 800 metres in elevation change from the Toodoggone River Valley, where porphyry copper-gold mineralization is exposed at surface, to Alunite Ridge and Quartz Lake where high and low sulphidation epithermal gold-silver mineralization has been discovered. The entire interpreted hydrothermal system is outlined by an impressively large multi-element soil anomaly (Figure 3).
Figure 3 Gold (left) and copper (right) in soil anomalies that define a 6.5- by 4-kilometre hydrothermal footprint on the Sofia property. The anomaly also spans 800 metres in elevation and encompasses porphyry copper-gold and high and low sulphidation epithermal gold-silver occurrences.
Limited historical work on the Sofia property includes 3,336 metres of drilling by Stealth Minerals in 2004 and 1,514 metres of drilling by BC Gold in 2007. In total the Sofia property has only been tested with 4,850 metres of drilling and there remain a number of important targets that have never been drill tested. One such target is the North Vein, which has only been identified in talus and subcrop but appears to have a 250-metre-long strike length. Six grab samples from the North Vein have gold grades ranging from 3.6 to 25.8 g/t (grams per tonne) gold, and 20.6 to 286 g/t silver.
Drilling by Stealth Minerals in 2004 targeted low-sulphidation epithermal gold-silver veins at Quartz Lake. Mapping, trenching and drilling defined a 225-metre strike length (that remains open) of gold and silver mineralized quartz veins, silicified breccias, and stockwork zones. Individual veins at Quartz Lake are up to 20 metres thick. Drilling mainly targeted the “A Vein” and numerous parallel veins at Quartz Lake are mainly untested by drilling. Stealth Minerals tested the Quartz Lake area with low diameter core (BTW), which resulted in poor core recovery and an insufficient test of even the A Vein. Despite the poor recovery, nearly every hole drilled by Stealth intersected significant gold and silver mineralization. The best result from their 2004 drill campaign was 3.5 g/t gold and 33 g/t silver over 11.6 metres (from 18.3 metres depth in drill hole SG-04-04).
The mineralized veins at Quartz Lake are part of a 4.8-kilometre-long trend of similar quartz veins (Figure 4), which have not been targeted with systematic drilling. Trenching along the trend resulted in samples up to 27.5 g/t Au and 1,131 g/t silver over 1 metre, and grab samples range up to 100 g/t gold and 2,425 g/t silver.
Figure 4 Historical map of sampling along the Sickle-Griz-Quartz Lake-Kevin vein system with superimposed 2004 and 2007 drill hole locations and >50 ppb (parts per billion) gold in soil anomalies (pink).
Drilling by BC Gold in 2007 targeted porphyry copper-gold systems with four holes testing the Sofia target and one hole testing the Alexandra target. Recent geophysical surveys conducted by QuestEx demonstrate that the Sofia target is underlain by an approximately 2.5- by 2-kilometre chargeability anomaly that contains multiple coincident magnetic anomalies. These geophysical signatures, along with the presence of strongly potassic altered and stockwork veined intrusive rock at surface, represent high-potential porphyry copper-gold targets. However, work by BC Gold in 2007 was guided by limited geophysical information and each of the four drillholes that tested the Sofia area missed the most prominent geophysical targets. Despite this, porphyry-related mineralized intersections were made (e.g. 0.12% copper and 0.08 g/t Au over 39 metres from 121 metres in drill hole BCG-07-01).
BC Gold also drilled a single 260-metre-deep hole at the Alexandra showing. The Alexandra showing covers a 1,000 by 500 metre area with highly anomalous gold (Au)-copper (Cu)-molybdenum (Mo) soil geochemistry (Figure 5), quartz-sericite-pyrite altered volcanic rock, and proximal geophysical (chargeability and airborne magnetic) highs. BC Gold’s single drill hole testing Alexandra had almost no recovery of core in the top 50 metres, and the hole bottomed in highly silicified volcanic rock grading 0.42 g/t gold and 0.08% copper over 21.20 metres, as it was approaching the outer shell of the burred magnetic anomaly.
Figure 5 Gold (Au), copper (Cu), and molybdenum (Mo) in soil anomalies overlying the Alexandra target.
2021 Exploration Plans
QuestEx is fully funded to conduct a 3,000+ metre drill program on the Sofia property in 2021. Three drill-ready exploration targets at Sofia will be tested during the Company’s 2021 exploration campaign. These targets were chosen based on their excellent potential for discovery of both high-grade epithermal gold–silver and porphyry copper copper-gold mineralization. The exploration targets are discussed in detail in news release NR21-04, dated February 9, 2021.