Source:
p. 2
The Project consists of 444 unpatented lode claims covering an area of 8,762 acres. All unpatented claims are 100% controlled by Viva Gold Corporation (Viva).
Deposit Type
- Breccia pipe / Stockwork
- Volcanic hosted
- Epithermal
- Vein / narrow vein
Summary:
The Tonopah property contains a low-sulfidation epithermal gold system associated with near vertical quartz-adularia-gold veins hosted by Ordovician black argillite of the Palmetto Formation and Tertiary rhyolitic volcanics and also in association with a discontinuity at the contact with the top of the Palmetto Formation and lower sequence of the Tertiary volcanics. Gold bearing veins occur in a series of enechelon clusters along a 1.5-mile northwest-trending band of mineralization. Contact related gold mineralization is also seen along this entire band. The main altered and mineralized zones are overlain by alluvial gravels, sand dunes, and playa deposits.
Structural geology significantly influences the distribution of mineralization and alteration at Tonopah. The Rye Patch fault system is a complex, oblique-slip fault system with numerous northwest trending splays, believed to be associated with north-south trending compressional stress common in the Walker Lane structural trend. Subordinate steeply dipping, north-south striking extension fractures developed between the two bounding strike slip faults.
Detailed structural studies of bedrock exposures and oriented core from 22 drill holes indicate that alteration and mineralization developed between two moderately northeast dipping faults with rightlateral strike slip movement. Veins and hydrothermal breccias developed along sub-parallel, north-south extension fractures that terminate at the northwest faults.
Two overlapping mineralized trends have been identified in drilling. The primary trend runs parallel to the west-northwest Rye Patch Fault System, bearing 290-300 degrees over at least 3000 meters, and 500 meters width, and open along strike. Mineralization within this trend is generally within the lower portion of the tertiary volcanics, and sometime in the uppermost argillites, parallel to the Opa/ Tv contact and is generally low to moderate grade, from 0.1 ppm to 5 ppm Au.
Secondary extensional fractures range from 345 to 360 degrees strike, are near-vertical in dip, and host veins and hydrothermal breccias with higher grade mineralization, ranging from 1.0 to over 30 ppm Au. These extensional fracture zones are best represented in drilling in the Discovery and Dauntless zones.
A discontinuity has been identified in drilling at the top of the Palmetto formation, where tertiary volcaniclastics and ashfall tuffs disconformably overlay the argillite. Significant alteration and mineralization is localized within a low-angle zone which includes and often parallels the erosion surface of the Palmetto, as well as several facies in the tertiary volcanics, particularly where veins and mineralized structures intersect this contact zone.
It is interpreted that ascending fluids entering the contact zone deposit precious metals in a favorable chemical and textural horizon in the base of the tertiary volcanics. Mineralization within this zone trends parallel to the Rye Patch right-lateral oblique-slip fault system, with a general azimuth of 330 degrees. Higher grade gold mineralization and associated alteration have been identified in a series of north-striking extensional structural zones within the overall mineralized trend, including the Dauntless and Discovery Zones. Gold mineralization in the Dauntless and Discovery occurs in zones of massive quartzadularia alteration in volcanic and volcaniclastic rocks of the Tombstone Formation and in veins, breccias, and silicified faults in both the Tombstone Formation and the underlying Palmetto Formation. Quartz-adularia alteration in the Discovery Zone tends to extend laterally in the Tombstone Formation immediately above and parallel to nonconformable contact with the Palmetto Formation associated low grade disseminated gold mineralization. In the Dauntless Zone, the quartz-adularia forms a funnel-shaped zone that expands upward into the Tombstone Formation above the moderately dipping nonconformity.
Alteration outside of the quartz-adularia zones in the Tombstone Formation is characterized as strong argillic alteration, which persists to the limits of drilling to date. Oxidation is extensive, and only local relict patches of incompletely oxidized pyrite remain in the many of the altered areas.
Significant gold mineralization occurs within the quartz-adularia altered zones, with higher gold grades associated with a variety of siliceous veins, and veinlets including chalcedonic, bladed or drusy quartz, and quartz +/- iron oxide cemented breccias. In the Discovery Zone, to the southwest of the mineralized zones in the Midway Hills and northwest of the Dauntless Zone, there is a strong predominance of steeply dipping north-south trends in mineralized veins and structures of the Tombstone Formation (Rhys, 2003).
The Discovery Zone is the most densely drilled zone at the Tonopah property. Drill holes have intercepted a large number of veins, breccia-veins, and mineralized structures occurring in sub- parallel clusters 3 to 6 meters apart. According to MGC, vein and mineralized structure thicknesses vary from a few centimeters to over 6 meters, averaging 2 meters; Gustavson did not sufficiently review drill core and drill hole data to confirm that estimate. Continuity of veins, vein zones and structures is projected, but not certain, over approximate north-south strike lengths of 60 to 150 meters, and with vertical dimensions that may locally exceed 100 meters. Continuity of gold mineralization and gold grades coincides, approximately, with projections of the veins and structures, but becomes far less certain at progressively higher gold grade cut- offs. At lower cutoff grades, good continuity develops between zones, veins and structures, due largely to lower grade mineralization associated with the discontinuity contact between the Palmetto Formation and the overlying Tombstone volcanics. There is a tendency for well-defined veins in the Palmetto Formation to branch and splay upward into a broader network of veins, vein zones, veinlets in the overlying Tombstone Formation volcanics. Gold mineralization is associated with the veins, breccias and structures, and lower-grade mineralization also spreads laterally in a more disseminated fashion associated with quartz-adularia alteration in the Tombstone volcanics. The system remains open at depth in the Palmetto Formation for lack of sufficient deep drilling.
Visible gold is commonly observed in and along the edges of veins, is frequently associated with hematite, and occurs locally in coarse form. Dendritic gold has been observed in core.
Siliceous structures oriented similarly to those in the Tombstone Formation occur in the underlying Palmetto Formation. Veins hosted in the Palmetto Formation form well-defined discrete veins and hydrothermal breccias up to 2 meters wide according to MGC. Alteration in the Palmetto Formation is characterized by argillic alteration extending up to a few hundreds of meters below the nonconformity with the Tombstone Formation. Intense argillic alteration is typically limited to a zone within one to eight meters of the nonconformity, with gradual weakening of bleaching and clay alteration to greater depth. Locally, the zone of intense quartz-adularia alteration in the overlying Tombstone Formation may extend into the Palmetto Formation for a few feet (Rhys, 2003).
Alteration and mineralization at the Tonopah property are typical of low-sulfidation, volcanic hosted epithermal gold deposits found elsewhere in Nevada and around the world. The deposit type is characterized by overall low original sulfide content, and quartz-adularia and clay-sericite alteration assemblages, among others. Vein textures are indicative of high level, near surface emplacement and include void fills, crustiform coatings, colloform banding, and comb structures.
Summary:
The Tonopah Property as planned in this report has a project life of 8 years, consisting of 2 years of preproduction, 5 years of mining and heap stacking, and one year of final gold recovery, pad rinsing and reclamation work. Mining will be done using traditional, open pit surface mining techniques. Mine operating and capital costs assume self-mining.
Three successive phases for the pit were designed based on the Lerchs-Grossman shape analysis and minimum push-back widths. These designs account for limitations based on minimum mining widths and wall angles indicative of operational feasibility. Pit exits have been designed to the north and east pit edges where feasible to minimize haul distances to the crusher and waste dump locations. The ultimate pit shape was based on the boundaries in the 91% price Lerchs-Grossman shape discussed in the previous sub-section. The target for road gradient through the main portion of the pits was 10%, with a 12% target in the final two benches. However, some stretches of road exceed the 10% target in small localized areas. A more detailed pit design will be done in future studies.
The ultimate pit shown is the combination of three phases composed of combinations of smaller pit bottoms within the greater geometry. There are a total of seven smaller pit bottoms in the ultimate shape. The first phase takes the first and highest grade pit threshold. The second phase includes four additional pit bottoms. The third and final phase mines the last two pit bottoms. Some waste stripping is common to the pit bottoms, thus the phases ensure that a minimum mining width of 30 meters is for any area that is expanded or pushed back. In scheduling the phases can be intermingled in some years. Given the geometry of the orebody, most of the realization of resource tons is in the intermediate to lowest benches of a given phase or pit bottom. Waste stripping a subsequent phase may often be done while still mining the final and most lucrative benches of the current phase in order to balance material movement flows and the cost/revenue streams.
Mineralization scheduled for mining is trucked to a 3 stage crushing plan located near the north eastern edge of the final pit. After crushing the material will be conveyed and stacked on the leach pad for gold recovery. Mine planning was carried out on the assumption of a 5-year mine life, attempting to balance the amount of mineralization per period in order to keep consistent feed to the crushing plant. This results in a planning target of approximately 2.5 million tonnes of mineralization per year. Waste materials are trucked to the waste dump to the north of the final pit edge.
After the completion of mining from the two sub-pits in the southeast, waste material will be used to backfill these areas. Waste material movement targets were set by balancing the truck operating hours after the required hours for mineralization movement were accounted for. These hours were calculated through a spreadsheet haulage model based on the length and road gradient traveled from each pit bench to the material destination for Caterpillar 777 haul truck. As pits deepen, leach pads and dumps ascend, haul times escalate, and overage tonnage capacities tend to be reduced.
Mineralization scheduled for mining is trucked to a 3 stage crushing plan located near the north eastern edge of the final pit. After crushing the material will be conveyed and stacked on the leach pad for gold recovery.
Processing
- Crush-and-stack plant
- Heap leach
- Carbon in column (CIC)
- Carbon adsorption-desorption-recovery (ADR)
- Cyanide (reagent)
Source:
Summary:
Process flowsheet and recoveries are based primarily on the 2019 McClelland Laboratories test work.
A process for treating the mineralized material was conceptualized based on the scoping level metallurgical test work. The process will consist of three-stage crushing to a nominal 80% passing 10 mesh product, which will be agglomerated and transported to the leach pad using a conveyor system prior to stacking by radial stacker.
The pregnant solution will be processed in an adsorption-desorption, refining (ADR) plant utilizing a carbon-in-column (CIC) circuit to recover gold and silver.
The planned processing capacity for crushing and heap leach is 7,000 tonnes per day (2.5Mt per year). The planned CIC circuit has a solution processing capacity of 400 cubic meters per hour and is equipped with a 2 - tonne carbon strip circuit.
Based on the column leach testing carried out by McClelland Laboratories, Gold recovery from argillite averages 83% ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Head Grade, g/t
| 0.78 |
Reserves at April 29, 2020:
Resources are presented at a 0.250 g/t (ppm) cutoff grade in argillite and 0.200 g/t (ppm) in volcanics, and inside a $1600/oz Au pit optimization shell.
Category | Tonnage | Commodity | Grade | Contained Metal |
Measured
|
3,930 kt
|
Gold
|
1.14 g/t
|
141,000 oz
|
Indicated
|
8,900 kt
|
Gold
|
0.65 g/t
|
185,000 oz
|
Measured & Indicated
|
12,830 kt
|
Gold
|
0.79 g/t
|
326,000 oz
|
Inferred
|
8,400 kt
|
Gold
|
0.67 g/t
|
181,000 oz
|
Corporate Filings & Presentations:
Document | Year |
...................................
|
2020
|
...................................
|
2020
|
...................................
|
2019
|
- Subscription is required.
News:
News | Date |
Viva Gold Files NI 43-101 Technical Report, Increasing Gold Resource at the Tonopah Gold Project in Nevada
|
February 28, 2022
|
Viva Gold Increases Gold Resource and Extends Mineralization at Its Tonopah Gold Project in Nevada
|
January 25, 2022
|
Viva Gold Drills 12.2 Meters at 5.7g/t Gold and 22.9 Meters at 2.0g/t at its Tonopah Gold Project in Nevada
|
November 11, 2021
|
Viva Gold Drills 22.9 Meters at 1.5 g/t, Including 4.6 Meters at 6.2 g/t, on a Significant Step-Out Drill Hole at its Tonopah Gold Project in Nevada
|
September 15, 2021
|
Viva Gold Corp. Terminates Arrangement Agreement with Golden Predator Mining Corp.
|
May 3, 2021
|
Viva Gold Affirms Support for Business Combination with Golden Predator
|
April 29, 2021
|
Viva Gold Provides Strong Drill Results from its Tonopah Gold Project, Walker Lane Gold Trend, Nevada
|
March 16, 2021
|
Golden Predator Mining Corp. and Viva Gold Corp. Enter Into Business Combination Agreement
|
March 3, 2021
|
Viva Gold Announces Further Drill Results With Step Out Holes Confirming Extension of Gold Mineralization at Its Tonopah Project, Nevada
|
October 14, 2020
|
Viva Gold Announces Initial Drill Results at Its Tonopah Gold Project in Nevada
|
September 9, 2020
|
Viva Gold Announces Filing of PEA for Tonopah Gold Project in Nevada
|
June 15, 2020
|
Viva Gold Announces PEA Results at Tonopah Gold Project
|
May 12, 2020
|
Viva Gold to Commence PEA Study at Tonopah Project
|
November 7, 2019
|
Viva Gold Provides Update on Tonopah Gold Project and Files NI43-101 Technical Report
|
July 16, 2019
|
- Subscription is required.