The Dublin Gulch property is located approximately 85 km by road north northeast of the Village of Mayo, Yukon. The Dublin Gulch claim block is situated within the Tintina Gold Belt and hosts the flagship Eagle Gold deposit as well as multiple other targets at various stages of development.
Large-tonnage reduced intrusion-related gold systems associated with Cretaceous Tombstone and Mayo suite granodiorite intrusions and structurally-controlled high-grade gold-sulfide veins.
The Dublin Gulch property comprises the flagship Eagle gold deposit and multiple adjacent prospects at various stages of exploration. Mineralization at Eagle is characterized by sub-parallel, gold-bearing sheeted quartz vein arrays that developed proximal to the contact between the Cretaceous-age granitoid Dublin Gulch stock and surrounding metasedimentary country rock. The density and continuity of the vein sets make the gold deposit amenable to open-pit mining. The property has been explored by a series of owners and operators, initially for tungsten and subsequently for gold. Victoria Gold acquired the Property in June 2009 and commenced drilling and other exploration work that same year.
The Property covers an area of approximately 555 square kilometers, and is the site of the Company's Eagle Gold Deposit. The Eagle Gold Mine is expected to be Yukon's next operating gold mine and, between the Eagle and Olive deposits, include Proven and Probable Reserves of 2.7 million ounces of gold from 123 million tonnes of ore with a grade of 0.67 grams of gold per tonne, as outlined in a National Instrument 43-101 feasibility study. The NI 43-101 Mineral Resource for the Eagle and Olive deposits has been estimated to host 191 million tonnes averaging 0.65 grams of gold per tonne, containing 4.0 million ounces of gold in the "Measured and Indicated" category, inclusive of Proven and Probable Reserves, and a further 24 million tonnes averaging 0.61 grams of gold per tonne, containing 0.5 million ounces of gold in the "Inferred" category. For additional information relating to the Property, refer to the technical report entitled “NI 43-101 Feasibility Study Technical Report for the Eagle Gold Project, Yukon Territory, Canada”, with an effective date of September 12, 2016, which is available on the Company’s profile at www.sedar.com.
Geology and Mineralization
The Dublin Gulch property is located in the north-central part of the Selwyn Basin on the northern limb of the McQuesten Antiform. The area is underlain by Proterozoic to Lower Cambrian-age Hyland Group metasedimentary rocks intruded by the Cretaceous Dublin Gulch granodiorite stock. The stock is elongate in a northeast direction and measures approximately five kilometers in length and two kilometers in width. The Eagle gold deposit is localized at the narrowest exposed portion of the stock, near its known western limit (Figure 1).
The Dublin Gulch intrusion has a U-Pb age date of 94 ±0.3 Ma (zircon; Shelby et al, 2003) and is a member of the Tombstone Plutonic Suite. It is predominantly composed of equigranular biotite hornblende granodiorite with minor diorite and granite phases. A pronounced metamorphic aureole in the surrounding Hyland Group rocks hosts subordinate amounts of gold in veins and breccia near the intrusive contact.
Eagle is characterized as a reduced intrusion related gold system (RIRGS). Mineralization comprises sub-parallel quartz, quartz-sulfide and sulfide-only veins that are best-developed within the granodiorite proximal to both the hanging wall and footwall contacts. The veins are also well developed within embayments and narrow portions of the stock. Individual veins are typically composed of white or grey quartz with subordinate potassium feldspar and range in width from one millimeter to more than 10 centimeters. Veins typically strike between 060° and 085° and have a near-vertical dip, and vein sets form steeply north-dipping to near-vertical zones that are amenable to bulk mining. Mineralization occurs as native gold, both as isolated grains and most commonly in association with arsenopyrite, pyrite and pyrrhotite.
Potato Hills Trend
The Potato Hills trend (PHT) is a >13 km-long belt of Au-As-Bi-Sb and Ag-Pb-Zn mineralization extending to the northeast and southwest of the Eagle deposit along the margins of the Dublin Gulch granodiorite stock and beyond (Figure 2). The trend hosts several gold prospects at various stages of exploration, all of which are expected to be accretive to the Eagle project, as well as the Rex and Peso silver targets. More advanced gold targets include Olive, Shamrock and Popeye. The PHT is approximately coincident with the regional scale Tombstone high strain zone associated with Jurassic-Cretaceous tectonics of the Cordillera, and the interaction of the Tombstone strain zone with the cooling host pluton is considered integral to the formation of gold mineralization at Dublin Gulch.
In contrast to Eagle-type mineralization, which is composed of vein arrays of thin, sub-parallel quartz and quartz-sulfide veins, mineralization along the PHT is generally characterized by a series of widely-spaced, structurally-controlled arsenopyrite-sulphosalt veins, distinct in both grade and style from the Eagle zone. Many of these veins were exploited historically and old shafts and adits can still be observed on the property. Mineralization in these veins is generally of a significantly higher tenor than in the quartz veins typically associated with Eagle-style mineralization, with visible gold observed in hand specimen and multi-ounce grades returned from grab samples. Silver grades exceeding 200 g/t Ag have been returned from grab samples along the PHT. Surface mapping and sampling, 2-3 km east of the Potato Hills, have also shown Au bearing samples in excess of 10 g/t Au (Table 1).
The Olive, Shamrock and Popeye zones, all of which are located between 2.5 km and 3.5 km northeast of Eagle, are the best examples of intersecting high-grade PHT-type veins and Eagle-style mineralization. Grab samples of thick arsenopyrite-scorodite-sulphosalt veins collected from Olive during the 2012 field season showed abundant disseminated visible gold and returned assays up to 189.5 g/t Au. 2010/2011 drilling in the Shamrock zone showed strong signatures of PHT mineralization, with grades of up to 118 g/t Au in restricted vein swarms. The PHT mineralization can commonly be seen cross-cutting and overprinting earlier Eagle-style mineralization, as well as reactivating and re-filling originally Eagle style veins resulting in significant gold endowment in areas of intersecting mineralization. Ongoing research into the metallogeny of the Dublin Gulch property suggests that PHT mineralization is most likely due to a second hydrothermal fluid event emanating from the Dublin Gulch granodiorite stock or from a deeper plutonic phase at depth.
Table 1. High-grade grab samples collected from the Potato Hills Trend
|Prospect||Au (g/t)||Ag (g/t)|