Gilbert South

Deposit Type

Low-sulfidation epithermal Au-Ag

Historic Production/Resource

Early 1900’s era (unrecorded)

Geology

Regional strike-slip fault w/ associated right-step forms a pull-apart basin. Multiple generations of overprinting epithermal veins in a oligocene-Miocene age bi-modal volcanic field in the walker lane trend.

Land Package

1,070 Ha

Exploration Target

Underground Gold (oxide/sulfide)

Geochemistry

Soil sampling,
Surface rock chips,
Legacy Drilling

Mapping

1:10,000 scale geologic map,
Remotely sensed hyperspectral alteration map

Previous Explorers

Atlas
Pathfinder
Inmet
Platte River Gold
Gold Summit
Renaissance

Geophysics

CSAMT

Drilling

81 RC Holes (>6,955 m)

Permitting

NA

Location, Infrastructure, and State of Exploration

This project (“Property” or “Project”) is comprised of 129 unpatented claims for a total of 1,050 hectares located 42 km west of Tonopah, Nevada (Figure 1) and is accessed by a US highway and 8 kilometers of county-maintained dirt roads. A well-developed network of secondary dirt roads spans the property.

Gilbert South lies within the Gilbert District, which has a long history of both production and recent resource drilling. Multiple small shafts and adits on the Property are developed along gold bearing epithermal quartz veins and vein stockworks. The Company considers this to be one of the best epithermal prospects in the Walker Lane Trend, which has a total gold endowment of over 80 Moz gold and 700 M oz silver[1].

The Property lies in a complex landscape of dacite and andesite flow domes and intrusions (Figure 2) that host multiple low sulfidation epithermal vein swarms throughout the volcanic package (Figure  3). The volcanic host rocks are commonly altered to clay minerals of illite/smectite, typical of high-level, hot springs related, epithermal systems. High grade gold occurs at the surface in both quartz/chalcedony veins and in hydrothermal breccia. Grades locally exceed up to 31g/t gold. Historic reverse circulation drilling, which occurred before Orogen Royalty’s recent surface exploration, indicate long runs of low-grade gold mineralization, but this drilling did not test the most prospective surface geochemistry, nor the potential deep feeder structures, which can host bonanza grades in this type of system. Field work by Eminent Gold’s (“Eminent” or “Company”) technical team who specialize in epithermal systems suggest that the types of vein textures and alteration are those that typical near the top of these systems (Figure 4).

Overview of the Opportunity

With several historic mines, robust gold in rock chip and soil samples and abundant outcrop of quartz veining, this property is prime for a successful exploration program. The Pretty Boy/Eastern Bounding (“EB”) Fault Zones Target Area yielded numerous rock chip samples with Au values from 7.4 g/t to 30.7 g/t within crustiform quartz veins. There are no drillholes in the vicinity of this sample. Additionally, this area has gold in rock samples up to 16.8 g/t taken over the span of a one-meter channel. A drill hole intercept near a historic mine area contained 1.5 m at 3.8 g/t gold. This area hosts numerous closely spaced veins that have never been adequately sampled (see photo in Figure 5). To the West of the Pretty Boy Target Area lies another prospective target; the Bighorn fault zone where historic rock chips yielded gold up to 4.5 g/t and contains the best gold-in-soil anomaly (<700 ppb Au) on the Property from the Company’s 2021 soil survey. The Bighorn Fault Zone Target has a strike length of 2.5 km and <0.75 km width. The Company’s goal is to understand the context of these historic shallowly mined occurrences in the context of the large, regional epithermal system in order to better focus on the primary upflow zone that fed the entire system which could host a multi-kilometer long bonanza vein.

Regional and Project Geology

Gilbert South exists in the Southern Monte Cristo Range which is comprised of a complex series of volcanic rocks that were erupted during the formation of the ancestral Cascade volcanic arc[2]. Known gold mineralization appears to correlate with multiple pulses of volcanism that range from ca. 22 Ma to 5 Ma. This episodic volcanism is associated with seven gold deposits which combined, have produced >1 Moz of gold[5].

Volcanism is one key factor involved in the development of a low sulfidation epithermal gold deposit, a second critical factor leading to the development of a prolific gold deposit is an appropriate structural setup, which Gilbert South has. The Monte Cristo Range lies in the greater Walker Lane tectonic region which extends from southeast to northwest across the southwestern portion of Nevada. The Walker Lane is a broad zone of crustal shearing and extension and a region with abundant gold and silver deposits. Strike-slip and high angle extensional faults are common features of Walker Lane tectonism and are often host to gold deposits in the region[2,3]. A large strike-slip fault transects the property from NW to SE, taking a significant right-step across the central portion of the property. Strike-slip faults are a prime structural feature as they quite often “step” from one location to another. These step overs are ideal points for the crust to pull apart, creating open space for gold bearing fluids to infiltrate and form a healthy gold deposit (Figure 6). Such step overs have formed deposits such as the Comstock Lode (~300 km to the NNW)[4] and Fruta Del Norte in Ecuador[5]. It is within the extensional openings formed as the crust pulls apart that mineralized quartz veins and stockwork veining typically form, a feature observed at Gilbert South.

As a whole, Gilbert South contains all of the features the technical team would identify as integral to discovering a large low sulfidation epithermal vein gold deposit; favourable structural setting, volcanism active during extensional faulting, and the degree of erosion has not carried away the deeper gold hosting portion of the system.  The Company is excited about the exploration possibilites at this property.

The Company's Initial Exploration Results

Results from the first phase of rock chip sampling and hyperspectral mapping suggest that the highest grade gold zone in this low sulphidation epithermal gold system may exist just below the surface. Significant gold in rock chip values range from 7.4 g/t up to 143 g/t gold in samples collected across the entire property. Soil results have demonstrated that the 1.5 km wide region in between the 2.5 km long Bighorn and Pretty Boy/EB faults is anomalously mineralized with gold in soils containing <0.70 ppm gold. Surface mapping indicates there are three primary north-south trending fault zones across the property that are associated with gold mineralized epithermal veins: the Pretty Boy-East Bounding fault zone, the Ohio fault zone, and the Bighorn fault zone. All three fault zones are structurally linked components of a right-stepover on a regional fault. This regional fault and related structures are key features of many gold-silver deposits in the prolific Walker Lane mineral trend.

Pretty Boy/East Bounding fault zone targets

The Pretty Boy and East Bounding fault zone is a 0.75 km wide zone of both stockwork veins and through- going bladed calcite and quartz veins measuring 1-2 meters wide.  The exposure of the vein network along strike varies due to topography and post-mineral gravel cover, but individual vein outcrops can be linked for 2.5 km along strike. Vein textures from mine workings and outcrop indicate a very shallow level of the epithermal system is exposed, suggesting that the primary boiling horizon for epithermal system could be preserved at depth.

The linked Pretty Boy and East Bounding faults are the focus of the most robust ammonium mineral alteration anomaly as detected by both an airborne hyperspectral survey as well as the handheld spectral survey on individual outcrops. Such an anomaly is interpreted to indicate a zone ~2 km long with a deep-rooted structure serving as the primary conduit for hydrothermal fluids that deposited gold-bearing epithermal veins. The direct link between ammonium and gold mineralization has been documented in other low sulfidation epithermal systems (Figure 7)[6,7,8,9,10,11,12]. The area of the ammonium anomaly is closely correlated with the highest-grade rock samples (Figure 8), as well as a strong gold in soil anomaly which is helping the technical team refine specific drill targets. Typically, rock samples are taken on stockwork veinlets which the Company’s technical team interprets to represent the uppermost portions above the boiling horizon of a larger vein that could be consolidated at depth (Figure 9). As is typical for epithermal systems, the vertical extent of mineralization is controlled by the level of boiling during vein formation, which could extend hundreds of meters down dip. Surface samples are predominantly taken from a welded tuff, which is rather friable and hosts mineralization as numerous stockwork veinlets. At depth the very competent argillite basement rock is a more suitable host for large open fractures and bonanza veins, a feature common to other epithermal systems in Nevada[10].

Bighorn fault zone target

The Bighorn fault zone is characterized by three subparallel faults, the easternmost of which has a semi-continuously exposed calcite vein that averages 1-3 meters wide and is 1.5 kms long.  The texture of the calcite vein, rhombohedral to banded, suggests the vein is the very shallowest exposure of an open fissure epithermal vein. At the northern extent of the Bighorn fault zone, the single vein horsetails into numerous en echelon veins within a poorly consolidated rhyolite dome. The strongest gold anomalies in the property wide soil survey confirm the surface expression of this target. Pending interpretations from a geophysical survey currently in progress will serve to image the potential for veins/silicified bodies at depth and that are obscured by the volcanic edifice at the surface.

Ohio fault zone target

The Ohio fault is characterized by a 1 km long fault that traverses relatively benign topography and is thus not well expressed at the surface. One- to two-centimeter-wide quartz veinlets are observed in dump samples from within this fault zone. Historical rock samples include grades of up to 8.6 g/t Au and rock chip sampling by the Company in 2021 provided Au assays from 12.5 g/t up to 143 g/t.

Secondary, Lower-Priority Targets Associated with Mafic Volcanics

The lower-priority vein systems are the Redback, Greenback and Indiana, that all are hosted in the younger sequence of mafic volcanics.  The veins from these target areas are typically 1-2 meters wide and are chalcedonic in texture, indicating very shallow preservation above the boiling horizon.  Due to the lower apparent concentrations of gold within these targets, and the targets not being clearly associated with a regional structural framework they have been the secondary focus of exploration activity. Again, the pending soil results will yield additional insights for potential at these target areas.

Description of Program

Numerous historic prospect pits that were not on previous maps were discovered during Phase I field work. Following the soil survey (results pending), the Company’s technical team also conducted a 2-week reconnaissance mapping program consisting of field checking existing 1:24,000 scale mapping and rock sampling: numerous channels and chips were taken at existing outcrops near the historic mine workings for which the Company had no or extremely limited data, especially in the Pretty Boy-East Bounding fault area. Two methods of spectral analysis were utilized by the technical team to expedite vectoring to the zones of highest temperature alteration and potential upwelling within the laterally extensive hydrothermal system. The first method used was remotely sensed hyperspectral data, acquired at a 2.5-meter pixel resolution by a fixed wing aircraft that captured >320 bands from 400-2450 nm. This data was acquired, and preliminary processing and interpretation completed by Spectir Advanced Hyperspectral Solutions (https://www.spectir.com/). Their interpretation mapped a widespread illite alteration extending across the property. The preliminary data received final interpretation by Browning Geosciences (https://www.browninggeoscience.com/) that used spectra from field collected samples to be used as ground truth and included in the spectral library for refinement in mineral identification of the  remote sensing data. The final interpretation identified multiple anomalies of ammonium illite within the laterally extensive field of illite alteration. Knowing that research demonstrating that ammoniated hydrothermal fluids interact with potassium-bearing minerals in wall work material to form ammonium illite or buddingtonite patterns along deep-seated structural fluid conduits and these same fluids also transport gold(8) the technical team used this as a parameter to vector field efforts.  To further verify and refine the ammonium illite anomalies the technical team also conducted a two-week ground based spectral mapping program using an ASD TerraSpec Halo mineral identifier to collect data in real time while traversing the project area. 1953 spectral measurements were taken across an equal number of samples sites. Mineral identification is done automatically by the unit by comparing measured spectral profiles to the USGS spectral library. 193 buddingtonite and 253 ammonium illite sample sites were identified at a >90% confidence level by the machine. A select set of the machine identified spectra were verified for their accuracy by Browning Geosciences and were found to be accurate mineral identifications. Field collected spectra verified the remotely sensed ammonium anomalies and identified which structures were the focus of ammonium illite and buddingtonite.

Geophysical Target Results

Nine transects of CSAMT (Controlled Source Audio-frequency Magnetotellurics) were collected by Durango Geophysical Operations (http://www.durangogeo.com) at 25-meter or 50-meter dipoles with lines spaced 500-meter apart to provide two-dimensional resistivity models (Figure 10). Computational Geosciences (https://www.compgeoinc.com) completed inversions of the two-dimensional data and integrated the data into a three-dimensional volume. Stratigraphic units are recognized by either their conductive (i.e., volcanic) or resistive (i.e., silicified siltstone basement) nature. Due to the resistive nature of the silicified basement rocks, structures serving as hydrothermal fluid pathways to form epithermal quartz veins appear as relative conductive anomalies due to clay alteration of the surrounding basement rocks. Major breaks in resistive bodies generally correspond to mapped structures (i.e., veins and faults). A 1.5 km wide block comprised by the Bighorn, Pretty Boy, and East Bounding (EB) faults contains several features that make the target appealing: 1) anomalous surface mineralization, 2) ammonium-bearing alteration which suggests the presence of deep-seated structures and, 3) new geophysics that indicates the existence of inferred, deep-seated structures (Table 1).

From west to east across the central portion of the Property there are three primary structures that form the heart of outlined exploration targets (Figure 11 & 12). On the western portion of the Property is the 2.5 km long Bighorn target, characterized by a subvertical, east-dipping, conductive anomaly that cuts a 500-meter-thick section of resistive basement. This anomaly suggests a deep-seated structure with up to a 250-meter-wide halo of alteration. The 2.5 km long Pretty Boy target is characterized by numerous subtle breaks in the resistive basement. These breaks in resistivity could indicate the mapped, 0.75 km wide stockwork vein zone cuts the basement rock at depth, and coalesces into a single feeder structure. Farthest to the east is the 2.5 km long EB target which is characterized as a resistivity break that is steeply east-dipping, comparable to the Bighorn target in scale. Branching off the EB fault is a subsidiary west-dipping fault and epithermal vein from which a 30.6 g/t Au sample was taken. Beneath the Pretty Boy and EB targets is a large conductive anomaly that may represent carbonaceous basement rocks which are thought to be a potential source of ammonium-bearing clays found at the surface. Ammonium-bearing clay alteration is indicative of the fertile, deep-seated nature of the target structures. All three structures are prime targets for bonanza epithermal veins.

Next Steps to Drill Targets

Compilation of all legacy and new data into a Leapfrog geologic model is allowing the technical team to refine drill targets on the Bighorn, Pretty Boy and EB structures. By integrating multiple lines of evidence; surface geochemistry, geology, spectroscopy and now geophysics, the technical team is identifying discrete vein targets both along strike and down dip of our multiple 2.5 km-long structural targets. Targets will be drill tested in Q3 of 2022.

Communities and the Environment

The pursuit of environmentally friendly and socially responsible mineral exploration and potential development guides the efforts and activities of Eminent Gold. Eminent Gold and our partners understand that the broad societal benefits exploration and mining can bring, but only when the risks and hazards of disturbing the environment are managed through careful and thoughtful implementation of sustainable practices. Eminent Gold strives to maintain the highest industry standards of environmental protection and community engagement at all of its projects.

Eminent Gold believes that sustainability includes pursuit of three mutually reinforcing pillars: environmental and cultural heritage protection; social and community development; and economic growth and opportunity. Eminent Gold assesses the environmental, social and financial benefits and risks of all our business decisions and believes this commitment to sustainability generates value and benefits for local communities and shareholders alike.

Ownership and Agreements

Eminent Gold Corp. and its subsidiary (the “Company”) and Orogen Royalties, an arm’s length party (the “Seller”) entered into a purchase agreement (“The Agreement”) on October 27, 2023. Pursuant to the terms of the Agreement, the Company may acquire 100% interest in the 110 unpatented claims (890 hectares). By way of Consideration, the Company will issue 350,000 common shares to the Seller. And an additional 200,000 common shares will be issued when the company initiates a drill program at Gilbert South Property, located 30 kilometres west of Tonopah in the Walker Lane trend, Nevada.

The Timberline claims are currently subject to a 3% net smelter return royalty, the Nevada Select claims are currently subject to a 2% net smelter return royalty, and the GL claims are currently subject to a 2.25% net smelter return royalty. The Company shall have the option and right to repurchase 1% of the GL royalty for $1 million (U.S.). The Seller shall have the option to buy down 1% of the Timberline net smelter return for $1.5 million (U.S.).

References

  1. Energyandgold.com, 2020, A Junior Mining Management Team That Doesn’t Know How To Lose Is Back With The Next Incredible Opportunity In Nevada Gold Exploration: Energyandgold.com.
  2. John, D.A., du Bray, E.A., Henry, C.D., and Vikre, P.G., 2015, Cenozoic Magmatism and Epithermal Gold-Silver Deposits of the Southern Ancestral Cascade Arc, Western Nevada and Eastern California in Pennell, W.M., and Garside, L.J. (eds.) New Concepts and Discoveries, Geological Society of Nevada, Reno, Nevada.
  3. John, D. A., 2001, Miocene and early Pliocene epithermal gold-silver deposits in the northern Great Basin, western United States: Characteristics, distribution, and relationship to magmatism: Economic Geology, v. 96, no. 8, p. 1827-1853.
  4. Berger, B. R., Tingley, J. V., and Drew, L. J., 2003, Structural localization and origin of compartmentalized fluid flow, Comstock Lode, Virginia City, Nevada: Economic Geology, v. 98, no. 2, p. 387-408.
  5. Leary, S., Sillitoe, R. H., Stewart, P. W., Roa, K. J., and Nicolson, B. E., 2016, Discovery, geology, and origin of the Fruta del Norte epithermal gold-silver deposit, southeastern Ecuador: Economic Geology, v. 111, no. 5, p. 1043-1072.
  6. Canet, C., Hernández-Cruz, B., Jiménez-Franco, A., Pi, T., Peláez, B., Villanueva-Estrada, R. E., Alfonso, P., González-Partida, E., and Salinas, S., 2015, Combining ammonium mapping and short-wave infrared (SWIR) reflectance spectroscopy to constrain a model of hydrothermal alteration for the Acoculco geothermal zone, Eastern Mexico: Geothermics, v. 53, p. 154-165.
  7. Krohn, M. D., Kendall, C., Evans, J. R., and Fries, T. L., 1993, Relations of ammonium minerals at several hydrothermal systems in the western US: Journal of volcanology and geothermal research, v. 56, no. 4, p. 401-413.
  8. Mateer, M. A., 2010, Ammonium illite at the Jerritt Canyon district and Goldstrike property, Nevada: Its spatial distribution and significance in the exploration of Carlin-type deposits, University of Wyoming.
  9. Simpson, M., Reflectance spectrometry (SWIR) of alteration minerals surrounding the Favona epithermal vein, Waihi vein system, Hgoldraki Goldfield, in Proceedings Proceedings of the GoldsIMM New Zealand Branch Annual Conference, Dunedin, New Zeeland2015, p. 490-499.
  10. Smith, J. M., 2014, Controls of High Grades within the Clementine Vein System in the Hollister Low-Sulfidation Epithermal Gold-Ag Deposit, NV, University of Nevada, Reno.
  11. Soechting, W., Rubinstein, N., and Godeas, M., 2008, Identification of ammonium-bearing minerals by shortwave infrared reflectance spectroscopy at the Esquel gold deposit, Argentina: Economic Geology, v. 103, no. 4, p. 865-869.
  12. Yang, K., Browne, P., Huntington, J., and Walshe, J., 2001, Characterising the hydrothermal alteration of the Broadlands–Ohaaki geothermal system, New Zealand, using short-wave infrared spectroscopy: Journal of Volcanology and Geothermal Research, v. 106, no. 1-2, p. 53-65.

Vein Targets

<700 ppb Au
Soil Anomaly

>3 g/t Au
Rock Sample

Mapped
Structure

NH4+
Anomaly

Geophysical
Anomaly

Bighorn 1

X

X

X

 

X

Bighorn 2

X

 

X

 

X

Bighorn 3

 

 

X

 

X

Pretty Boy 1

X

X

X

X

X

Pretty Boy 2

X

X

X

X

X

East Bound 1

 

X

X

X

X

East Bound 2

 

X

X

X

X

Table 1. Compilation of key features indicative of the presence of epithermal veins at depth considered for each target.

Gilbert South Project Figures