Yellowknife City Gold Project
Tom Setterfield, Joe Campbell, Alan Sexton
GeoVector Management/TerraX Minerals Inc
TerraX's 116 sq km Yellowknife City Gold Project (YCGP) is underlain by the prolific Yellowknife Greenstone Belt both north and south of Yellowknife. The YCGP covers 23 strike km of the extensions of the shear system that hosts the high-grade Con and Giant gold deposits. It also contains multiple shears that are recognized hosts for gold deposits in the district.
The Yellowknife Greenstone Belt is analogous to the Abitibi Greenstone Belt in Ontario/ Quebec, but has not received nearly as much academic or exploration attention. It contains metavolcanic rocks of the >2.70 Ga Kam Group and the 2.69 to 2.66 Ga Banting Group, intruded in the west by 2.63 to 2.608 Ga granites, and overlain to the east by 2.661 Ga turbidites. The Kam and Banting groups are separated by the Hay-Duck Fault, which is a major crustal break, typically an important feature of mesothermal gold terranes. The sedimentary Jackson Lake Formation occurs proximal to the Hay-Duck Fault; it is considered an analogue to the Timiskaming Conglomerate of the Abitibi. The Con and Giant deposits are hosted by Kam Group dominantly mafic rocks, as are most important targets in the YCGP.
Most known gold mineralization in the YCGP occurs in north to northeast-trending structures. This includes TerraX's three main areas of focus, the Crestaurum and Barney shear zones and the Barney Deformation Corridor. The northeast-trending, ~45°SE-dipping Crestaurum Shear hosts the Crestaurum deposit and drill intersections as high as 5.00 m @ 62.9 g/t Au. Mineralization consists of pyrite, arsenopyrite, visible gold, stibnite, sphalerite and galena, hosted by quartz ± ankerite vein arrays that pinch and swell along strike and down-dip. The shear has only been drill tested to a vertical depth of 120 m.
The north-trending, subvertical Barney Shear is traceable for at least 10 km, and is mineralized over ≥600 m strike length, including intersections as high as 22.4 m @ 6.35 g/t Au. Mineralization typically occurs in multiphase, deformed quartz-ankerite veins, locally with significant pyrite and/or arsenopyrite, and lesser galena and sphalerite. The highest grade mineralization encountered to date is at a vertical depth of 240 m.
Geological mapping in 2015 identified the >500 m wide, north-northeast trending Barney Deformation Corridor, featuring several areas of extensive sericite alteration. An important new showing (Hebert-Brent) with an 11 m wide sulphide-sericite-ankerite schist shear zone was discovered. Initial channel samples from the showing returned 11.0 m @ 7.55 g/t Au. Mineralization is replacement style, and unusually for the Yellowknife gold camp, there is a noticeable lack of quartz veining. Mineralization consists 20% to 60 % semi-massive, fine-grained sulphide needles. Subsequent exploration work revealed at least two more nearby significant showings, with channel sample results of 6.0 m @ 10.26 g/t Au and 15.3 m @ 2.23 g/t Au, including 6.00 m @ 4.05 g/t Au.
Besides these three main targets, TerraX has discovered/rediscovered numerous quartz vein-related showings, many of which are at the drill-ready stage. Additionally, TerraX has discovered molybdenum-rich quartz veins (best grab sample 6.32% Mo) close to the 2675 Ma Ryan Lake Pluton, 500 m west of the Crestaurum Shear. This pluton was intersected at a vertical depth of ~500 m immediately west of the Barney Shear, at which point it contained anomalous molybdenum and gold, and adjacent volcanics contained anomalous copper. TerraX is starting to factor this apparent porphyry style mineralization into ongoing exploration strategies. Structurally hosted base/precious metal mineralization (best TerraX drill intercept 3.42 m @ 3.41 g/t Au, 69.3 g/t Ag, 3.67% Pb and 3.17% Zn) occurs in the northern part of the project area; this has been examined only in a cursory fashion by TerraX.
Tom Setterfield obtained a BSc from Carleton University (1980), an MSc from the University of Western Ontario (1984) and a PhD from Cambridge University (1991). He has lived and worked in Australia, Fiji, England and Canada as well as on assignment in many other countries. As a consultant for QGX Ltd, he was that company's first representative to visit the Golden Hills area in western Mongolia, and was integral to the decision to acquire this property, upon which an economic gold-rich VMS deposit was later discovered. Dr. Setterfield co-founded the consulting group GeoVector Management in 2002. He also co-founded Monster Copper Corporation and served as a director and VP Exploration from its incorporation in 2002 to its takeover by Mega Uranium Ltd in 2007. He co-founded TerraX Minerals Inc. in 2007, and presently serves as a director and VP Exploration.