Summary:
The Elk Gold Project is indicative of a reduced intrusive-related, structurally controlled quartz vein system. The gold- and silver-bearing quartz veins have historically been characterized as mesothermal based on fluid inclusion studies. The fluid inclusions within quartz crystals in the veins indicate gold mineralization formed at a minimum temperature of 250°C and a pressure of 2.5 kbar, corresponding to lithostatic pressure at a depth of 7 km (Geiger, 2000). Considerable open space within the veins, not related to weathered pyrite, suggests a much shallower vein emplacement, and more study will be needed to resolve the apparent conflict. The vein systems consist of structurally controlled; narrow, pyritic quartz veins hosted in granitic as well as volcanic rocks near the contact between these two primary lithologies. Emplacement of quartz veins is thought to be related to Tertiary Otter intrusions.
The Property hosts nine zones containing gold mineralization, including Siwash North, Siwash East, Gold Creek, Lake, End, Discovery, South, Bullion, and Nicola.
Gold mineralization occurs within quartz-sulphide veins and stringers, most often within phyllic- and silica-altered Osprey Lake rocks and adjacent phyllic- and silica-altered Nicola volcanic rocks. Pyrite is the most common sulphide (Conroy, 1994), ranging from 5% to 80%, with higher percentages often associated with chalcopyrite and tetrahedrite. Gold occurs asfine-grained free gold (typically lessthan 50 µm) in quartz, and within quartz-pyrite boxwork, and in fractures within veins(King, 2001). Gangue minerals include quartz and altered wall-rock clasts (xenoliths), with minor amounts of ankerite, calcite, barite, and fluorite. Most of the previous mine production occurred within the quartz-monzonite and granodiorite border phase of the batholith (Lewis, 2000).
Siwash North Zone
Mineralization is dominantly vein-hosted, consisting of pyrite-chalcopyrite-sphalerite-galena- arsenopyrite, with a small amount of visible gold-pyrrhotite-molybdenite and potential sulphosalts, as well as gold-bismuth phases (maldonite?). Except for the rare pyrrhotite, this generally indicates an intermediate sulphidation state of the system. In general, gold grades appear to correlate well with total sulphide content, with base metals being a positive indication; however, base-metal-dominant yellow-brown quartz veins were found to be poor hosts for gold mineralization.
Sulphides occur in one of six forms: 1) vein-hosted, 2) stringer-hosted, 3) mineralized gouge, 4) base- metals in honey quartz veins, 5) blebs within altered clots within the Nicola Group rocks, or 6) disseminations in intrusive units. The vein-hosted and stringer-hosted sulphide minerals are similar and likely formed as part of the same event. The mineralized gouge is simply interpreted to be a pulverized quartz-sulphide vein related to the same event.
Lake Zone
The Lake Zone, 800 m south of the Siwash North Zone, contains numerous gold-in-soil anomalies that range up to 1,210 ppb Au. Two of these anomalies were tested by trenching in 1989, in which an argillic-altered pyritic andesite dyke returned values up to 12.69 g/t Au over 0.86 m. Additional trenching in 1990 returned values up to 30.69 g/t Au over 0.34 m. A second 1990 trench, 150 m west of the former, exposed the gold-mineralized zone from which a grab sample yielded 40.39 g/t Au.
South Zone
Located approximately 3 km south of the Siwash North Zone, the South Zone has been tested by drilling 51 diamond drill holes (6,000 m) from 1995 to 2013. Drilling intersected a series of subparallel, narrow, gold-mineralized zones: as many as seven discrete vein sets in drill hole SND11-144.
Gold Creek Zone
Located approximately 150 m south of the west end of the Siwash North Zone, the Gold Creek Zone was initially investigated to follow up on soil geochemical and very-low-frequency (VLF) electromagnetic geophysical anomalies. Mineralization is similar to Siwash North in that gold bearing pyritic quartz veins are hosted in the Osprey Lake quartz monzonite.
Siwash East, End, Discovery, Bullion, and Nicola Zones
Five zones have been drill-tested north and south of the Siwash North Zone, although not to the same extent as the previously described zones—Siwash East, End, Discovery, Bullion, and Nicola. The five zones were tested by 32 diamond drill holes (2,638 m). All but the Nicola Zone intersected narrow gold veining, with multiple veins noted in the Bullion and Discovery zones.