Summary:
Mineralization in the Good Hope Deposit and Golden Ace Zone can be classified as examples of a structurally controlled, locally disseminated, sediment-hosted, mesothermal quartz vein gold.
The Project is hosted within the Bare Mountain Complex which lies within an intricate tectonic setting of the Nevada Basin and Range Province.
The gold mineralization in the Good Hope Deposit is spatially associated with, and along, the Good Hope fault zone, and is primarily hosted in altered and veined Wood Canyon Formation, and to a lesser extent, in the Juhl and Sutton Members of the Stirling Formation. Mineralization hosted along the contact between the Sutton and Morris Marble Members of the Stirling Formation is referred to as the Gold Ace Zone. Although there are small historic prospects along the Good Hope fault zone, most of the historic production came from the Gold Ace Zone.
Good Hope Fault Zone
Within the Project area, the east-dipping Good Hope fault zone ranges from 15 m (50 ft) to 192 m (630 ft) in width and has a 1,585 m (5,200 ft) strike extent. The fault zone has an overall northerly trend but between 5100 N to 3000 N rotates to a north-northwest trend. The fault zone juxtaposes Bonanza King Formation in the hanging wall block, Wood Canyon Formation in the central fault zone and Late Proterozoic units in the footwall.
The fault zone comprises the Good Fortune fault that is located on the eastern or hanging-wall side and has a moderate dip, while the Good Hope fault defines the western (or footwall) extent and has a steep dip. The Good Hope fault controls the majority of the known alteration and gold mineralization.
Textures observed within the fault zone include breccias, quartz veins, elevated silicic alteration and localized clay-rich zones. Exposed quartz veins display a dominant northerly trend and secondary sigmodal veins display an east-northeast trend. Veins measurements from oriented drill core highlight two dominant vein sets with orientations that include a moderate dip to the southeast (45°-->140°) and a steep dip to the northeast (70°-->050°; Brown, 2018). The line of intersection for these two vein sets is moderate dip to the southeast (43°-->120°).
Alteration
Four main alteration assemblages are observed across the Project: silicic, sericite, argillic, and propylitic, and these are spatially associated with the Good Hope fault zone.
Silicic alteration along the Good Hope fault laterally extends 15 m (50 ft) to 30 m (100 ft) toward the Good Fortune fault. Alteration within the central fault zone appears to have preferentially developed along moderately dipping bedding planes within the Wood Canyon Formation. Alteration intensity ranges from intense to weak and is typically associated with quartz ± adulariacalcite veins, goethite after pyrite, and local coarse adularia. Quartz veining varies in thicknesses from millimeters to meters.
Exposed quartz veins are commonly coated by manganese oxides and hematite. Massive white quartz veins are more abundant than banded veins. Prominent massive veins are exposed in the footwall block at the northern extent of the Good Hope Deposit. Colloform vein textures are observed at Ollie’s Follie target (Barcia, 2017).
The sericite assemblage is preferentially developed within mica-bearing units and is locally overprinted by silicic alteration.
Argillic alteration is locally restricted along portions of fault planes and characterized by the presence of kaolinite.
Propylitic alteration consists of calcite, chlorite, and ankerite. Calcite veinlets and stringers are observed throughout most units. Chlorite is preferentially developed in finer-grained units and biotite has been partially to pervasively replaced by chlorite.
Oxidation (Redox)
The redox zones within the Project area include an upper oxide and a lower transition zone. The upper oxide zone is characterized by hematite, goethite, pyrolusite and minor jarosite. Oxidation is strong within and adjacent to the Good Hope fault and decreases in intensity outward from the fault. The depth of the oxide zone ranges from 30 m (100 ft) to 152 m (500 ft) below surface (between 1,183 m (3,880 ft) to 1,027 m (3,370 ft) elevation ASL). Iron oxides comprise up to 5% of the rock mass.
The transition zone is located below the base of the oxide horizon and consists of both goethite and pyrite. In the transition zone, sulphides comprise < 1% of the rock mass. The transition zone reaches the maximum depth of drilling on the Project at an elevation of 3,099 ft.
Mineralization
Mineralization that supports Mineral Resource estimation is hosted in the Good Hope Deposit and the Gold Ace mineralized zone. Anomalous gold values are associated with quartz veining and/or iron-oxide-bearing, silicic-altered rocks in both areas. Pyrite and iron oxides are the dominant minerals associated with gold mineralization. Visible gold was identified on fractures in sericitealtered rocks, on quartz-adularia-coated fractures, and in hematite-filled cavities, pervasively silicic-altered rocks, goethite pseudomorphs, thin quartz veinlets, and goethite-rich fractures and cavities. Visible gold has been observed along the Gold Ace trend in surface samples and drill core, whilst it was observed only in drill core from Good Hope.
Description of Mineralization: Good Hope Deposit
Gold mineralization at the Good Hope Deposit is primarily hosted in altered and veined Wood Canyon Formation, and to a lesser extent, in the Juhl and Sutton Members of the Stirling Formation. Gold mineralization is associated with:
• Silicic and/or sericite-altered rocks.
• Zones of increased quartz vein density.
• Faults, breccias, and/or highly fractured zones with abundant iron oxides.
• Units with high concentrations of goethite pseudomorphs after pyrite.
• Quartz-adularia veinlets.
Mineralization at the Good Hope Deposit varies in width from 15 m (50 ft) to 192 m (630 ft), has a strike length of 1,585 m (5,200 ft) and has been intersected to a vertical depth of 213 m (700 ft) below surface.
North of 5100 N, mineralization is spatially associated with the sub-vertical, north-trending Good Hope fault and is up to 149 m (190 ft) wide. Section 5600 N outlines mineralization north of 5100 N.
In the central portion of the deposit between 5100 N and 3000 N, mineralization is also associated with the Good Hope fault. Mineralization extends to the east with a shallow to moderate dip towards the hanging wall of the Good Fortune fault. Mineralization has been intersected along the Good Fortune fault and appears to be sub-parallel to the dip of the fault. In this central portion, mineralization is up to 192 m (630 ft) thick and coincides with a change in fault zone strike from north to north-northwest. Sections 4200 N, and Section 4800 N outline mineralization in the central part of the deposit.
South of 3000 N, the gold mineralization continues to be spatially associated with the sub-vertical, north-trending Good Hope fault, and is up to 55 m (180 ft) thick.
Description of Mineralization: Gold Ace Mineralized Zone
Mineralization at Gold Ace is dominantly located along the contact between the Sutton and Morris Marble Members. At the mineralized contact, the Morris Marble Member is characterized by silicic alteration and hematite. Evidence for mineralization parallel to the contact between the Sutton and Morris Marble Members is provided by low-angle, east-dipping stopes from historical underground mining. The northwest-trending Gold Ace Zone consists of several discrete structures. The overall continuity of mineralization at Gold Ace is less well developed than at the Good Hope Deposit.
Mineralization at the Gold Ace varies in width from 1.5 m (5 ft) to 21 m (70 ft), has a strike length of 640 m (2,100 ft) and has been intersected to a vertical depth of 91 m (300 ft) below surface.