Project of the Week: Snowline Gold Corp

6th December 2021

 

 

Canada and gold. The two go together like milk and cookies, or like hammers and geologists. That’s why we can’t stop featuring Canadian gold companies in our Project of the Week article. Last week, Luke wrote a phenomenal piece on Labrador Gold and their Kingsway project in Newfoundland. This week, we are going more than 4,500 km to northwestern Canada in the Yukon Territory to highlight one of the premier new exploration teams and the greenfield gold projects they have jumped on over the past year.

Snowline Gold Corp (CSE: SGD; OTCQB: SNWGF), formerly Skyledger Tech Corp, has put together a suite of properties which have been privately amassed by the board of directors through years of prospecting. With over 900 km2 of concessions in the Yukon and 3 distinct styles of gold mineralization, Snowline has placed themselves in a low-risk, high reward position to proceed with exploration on undiscovered mineral systems. Of their 7 properties, 5 lie within the Selwyn Basin along established gold trends, the Rackla and Tombstone gold belts (Fig. 1).  The Selwyn Basin hosts several important gold deposits, such as Eagle with 3.6 Moz of gold, and intrusion/porphyry style mineralization in the Tombstone Gold belt further to the west in the Fort Knox district near Fairbanks.

Figure 1. Map of the Yukon Terriorty and the location for mining concessions owned by Snowline Gold Corp. Note the proximity of word class gold deposits to Snowline’s project areas.

Project diversity and low risk are primary goals for the management team at Snowline Gold, headed by CEO Scott Berdahl. Along with the advisory board consisting of influential prospectors, geologists, and investors including Craig Hart, Ron Berdahl, and Quinton Hennigh, Snowline Gold has assembled an impressive team of exploration geologists and finance professionals. Recently, one of their geologists, Jerome de Pascale, was awarded the title “Prospector of the Year” by the Yukon Prospector’s Association — an impressive achievement! With a strong team in place, Snowline has spent the 2021 season aggressively exploring, mapping, and drilling. Below - I’ll highlight their most exciting projects based on deposit style!

Orogenic Gold

Following our recent articles on Canadian gold, our readers should be reasonably comfortable with orogenic gold deposits! These deposits form during the release of fluids during mountain-building events when rocks get cooked and metamorphosed at high pressures. These fluids travel upwards along major crustal structures and are known to form quartz veins full of arsenopyrite and gold. This style of gold mineralization is known as lode gold, and is responsible for the gold rush in the Sierra Nevada as well as the Yukon during the 1800’s. These deposits are often found by exploring stream sediments in search of gold placers - where gold and other heavy minerals collect in riverbeds.

Snowline has 3 orogenic gold prospects in the works: the Tosh, Einarson, and Cliff properties all host promising gold targets. The Tosh property is hosted in high-strain schist with marble lenses of the Tanana terrane in a historical placer district. Early results from grab and soil sampling indicate gold anomalies up to 6.8 g/t. The Cliff property about 100 km to the southeast, is also hosted in similar schist terrane with historical exploration indicating similar soil anomalies. The real gem of these deposits however is the Einarson Property.

The Einarson property is one of the flagship projects for Snowline and has been the focus of the most recent exploration efforts. Located to the southwest of the Selwyn Valley Thrust, the Einarson property hosts the Jupiter, Mars NE, and Avalanche Creek orogenic gold prospects. Each of these deposits are hosted in the uplifted sedimentary package of the Proterozoic Narchilla formation, composed of siltstones and carbonates and older Algae Lake Formation (arenite, conglomerate, limestone). These sediments are cut by quartz veins which host sulfide mineralization. The Jupiter target, a blind target discovered by drilling during the 2021 season, has been incredibly fortuitous for the exploration team. Five bands of gold mineralization in quartz-carbonate-sulfide (generally arsenopyrite) veins have been identified in with grades reaching up to 45 g/t and visible gold observed (Fig. 2). These veins are associated with alteration of Narchilla siltstones with anomalous As and Sb - indicators for orogenic gold (NI-43-101; Goldfarb et al., 2015).  The arsenopyrite (and gold!) is commonly hosted in fold hinges, delivered by structurally controlled fluid pulses that were likely coeval with deformation.

Figure 2. Cross section and interpretation of mineralization at the Jupiter target. Jupiter was a blind discovery and has turned into one of the most exciting developments at the Einarson project, with 5 high-grade gold zones.

Intrusion Related Gold

Intrusion related gold deposits are well known in Alaska and the Yukon in the so-called Tintinia Gold Belt, which hosts the Fort Knox (11 Moz), Dublin Gulch (4 Moz), and Brewery Creek (1.8 Moz) deposits. These deposits occur due to magma production late in the orogenic process and emplacement of reduced intrusions, distinctly different to arc magmatism from other parts of the Cordillera. These deposits are generally gold rich, with minor copper, and high Bi, Te, As and Sb contents - elements that also correspond with orogenic mineralization (Fig. 3).

Figure 3. A model for Intrusion-related gold systems in the Tintinia belt in the Pacific Northwest. The geochemical anomalies associated with the reduced mineral system are consistently observed at world class deposits in the region, such as Fort Knox and Brewery Creek. Figure modified from Hart (2007).

Snowline’s holdings include 3 intrusion related gold systems associated with reduced igneous systems: Rogue, Rainbow, and Cynthia. While the Rainbow and Cynthia deposits exhibit geochemical characteristics comparable to the other Tintinia gold deposits, they are prospective based only on historical exploration data (Fig. 4). The Rogue property is the flagship property, with the Valley and Gracie targets exhibiting strong surface anomalies (up to 95.3 g/t at Valley and 57 g/t at Gracie from surface rock grab samples; NI-43-101). Recent drilling at the Valley target has interested visible gold in as many as 28 quartz veins interested by the V-21-001 core (September News Release). Keep on eye on these developments as Snowline forges ahead looking for the next big intrusive gold system.

Figure 4. Outcrop from the Cynthia project showing oxidized hornels and mineralization zones across the rugged, barren terrain of the concession. This style of alteration is present at the kilometer scale, providing hope for a big discovery!

Carlin-type Gold

What are Carlin-type prospects? It’s been a while since we got into this deposit style, but these are sedimentary-hosted gold deposits hosted in reduced sedimentary sequences (such as those in the Narchilla formation!). Carlin-type gold is generally hosted in carbonaceous black shales, deposited when fluids travel along deep-seated faults (plenty of those here, if you’re paying attention!) intersect the reduced organic matter present in the black shales (Cline et al., 2005). This results in the reduction of the sulfur, which causes sulfide crystallization and the precipitation of gold from the fluid (Large et al., 2011). Gold in these systems is often invisible, hosted within pyrite. As for grade, well, just because it’s invisible doesn’t mean it’s not there! Similar deposits are some of the richest in the world, such as the Betze-Post deposit in Nevada (45 Moz gold) and the Sukhoi Log in Russia (63 Moz).

Figure 5. A general model for Carlin-type mineralization. Deep-seated faults act as fluid conduits (from metamorphic or magmatic fluids) which carry gold and sulfur which is reduced when it intersects the carbonate or black shale sedimentary packages near the surface.

Two of Snowline’s properties exhibit evidence for this style of deposit, with targets at both the Einarson and Ursa locations. Einarson offers the Mars, Misty, and Odd targets - each with anomalous gold zones and Carlin pathfinder elements. These can be difficult to distinguish from epizonal (shallow) orogenic gold deposits, but the difference is the lack of structurally controlled quartz veins. Most of the Einarson targets are hosted in siliciclastic and carbonate units of the Narchilla Formation, but the Ursa group is hosted entirely within the carbonaceous, continental margin derived shales that have become synonymous for carrying invisible gold (Fig. 6). The Ursa project is further mounting interest, with large-scale mineralization potential, along a 9-km trend of anomalous gold in stream sediment/soil. A September news release (here) reported the completion of a VTEM survey at Ursa which will guide drilling moving forward.

Figure 6. Snowline chairman, Craig Hart, sampling black shale at the Ursa project in August 2021.

Overall, the experience of Snowline’s management team, coupled with their savvy gold portfolio encompassing  a variety of deposit styles in the Selwyn Basin make for a rosy outlook. We look forward to more news releases from these greenfield exploration projects this winter as they process data from the summer field season. Likewise, next summer, as temperatures increase, we will watch as the snow line rises and Snowline Gold begins the next phase of exploration!


References

Cline, J.S., Hofstra, A.H., Muntean, J.L., Tosdal, R.M. and Hickey, K.A., 2005. Carlin-type gold deposits in Nevada: Critical geologic characteristics and viable models. Economic Geology 100th anniversary volume451, p.484.

Goldfarb, R.J. and Groves, D.I., 2015. Orogenic gold: Common or evolving fluid and metal sources through time. Lithos233, pp.2-26.

Hart, C.J., 2007. Reduced intrusion-related gold systems. Geological Association of Canada, Mineral Deposits Division5, pp.95-112.

Large, R.R., Bull, S.W. and Maslennikov, V.V., 2011. A carbonaceous sedimentary source-rock model for Carlin-type and orogenic gold deposits. Economic Geology106(3), pp.331-358.

Aaron Hantsche

View posts by Aaron Hantsche
Aaron Hantsche recently obtained his PhD in Geology from the University of Geneva in Switzerland, where he studied distal Pb-Zn skarn deposits in southern Bulgaria. Magmatic-hydrothermal deposits are his primary focus, with a bent towards geochemical vectoring tools and field geology. In addition to his work as a geologist, Aaron is a director for the science communication platform, Ore Deposits Hub. His passion for mineral deposits and geo-communication led him to join the Spotlight Mining writing team in October 2021.