Precious Metals Exploration
Exploring around the old trends
Precious metal exploration in Nevada has traditionally been concentrated around three primary trends: the Carlin Trend, the Battle Mountain-Eureka-Cortez Trend, and the Walker Lane Trend. Together, these three trends have contributed to the nearly 170 million ounces of gold produced in Nevada between 1835 and 2018 and have given rise to some of the world’s most important mining districts. Though Nevada hosts a variety of deposit types, including porphyry and skarn, most of the state’s gold production comes from low-sulfidation epithermal gold and sediment-hosted Carlin-type deposits.
The presence of Carlin-type deposits is one of the main appeals for explorers in Nevada. These are large sedimentary rock-hosted disseminated gold deposits which often occur near-surface and in clusters, with one large “elephant” deposit surrounded by a group of smaller satellite deposits with similar geology.
Finding more gold and silver in Nevada
Exploration spending in Nevada since 2011 has been directly linked to commodity prices. It has been gradually increasing for four consecutive years, yet this has not translated into more production. “Despite explorers spending more money over the last decades than ever before, discovery and production rates have declined steadily since the late 1990s,” expressed James Buskard, president of Nevada Exploration.
This can be attributed to the fact that most of the low hanging fruit, the shallow, multi-million-ounce oxide deposits, have been discovered and mined out, so the new discoveries are coming from deeper deposits that are more difficult to find. New discoveries, such as Nevada Gold Mine’s recent discovery of the huge 15 million-ounce Goldrush deposit, tend to result from rethinking the geology of previously mined areas and drilling underneath the near surface mineralization. Therefore, many explorers in Nevada are currently going deeper to find high-grade, refractory deposits.
There are also companies focusing in underexplored areas of Nevada in hopes of finding the next major discovery, which is the case of Nevada Exploration. “Nevada Exploration was founded with the sole focus of looking for Nevada’s next large Carlin-type gold district in the 50% of the state where the bedrock is covered by sand and gravel beneath large desert valleys. These valley basins have been under-explored due to an historic lack of specialized undercover exploration tools,” Buskard explained.
For Chad Peters, president, CEO and director of Ridgeline Minerals, there are other factors that play an important role apart from technology. “In the last 10 years, the discoveries made have relied on good teams, layering the data together, and testing concepts,” he argued.
Millennial Precious Metals (MPM) has become one of the protagonists around Nevada’s Carlin Trend and the Battle Mountain Eureka Trend. In 2021, the company started a phased 15,000-20,000 m drill program across its three key assets. It began its exploration campaign by drilling approximately 2,300 m at Red Canyon, a Carlin-style, sediment-hosted gold project, which revealed some encouraging results. “Widths and grades are 54 m to 22 m, ranging from 0.5 g/t to 4.5 g/t oxide Au. It is important to note that the average grade in the Great Basin is significantly lower, about 0.38 g/t Au, which is why our asset is receiving significant attention in the market,” stated president, CEO, and director Jason Kosec.
MPM has also started drilling over 7,000 m at Mountain View and 4,000 m at Wildcat located in the Carlin Trend.
"Our four projects lie on the Carlin and Battle Mountain trends of Nevada, equating to 154 km2. We took an old-school approach by acquiring core land positions in historic multimillion ounce gold trends, and conducting systematic early-stage exploration such as soil sampling, mapping, and geophysics followed by re-building of the geological models from scratch."
Chad Peters, President and CEO, Ridgeline Minerals
Battle Mountain - Eureka Trend
Between the Carlin and Battle Mountain trends, Nevada-focused junior gold and silver explorer Ridgeline Minerals has become one of the largest landholders of any junior in the state, with four projects comprising 154 km2.
The company completed an IPO in August 2020 and achieved a huge milestone in the company’s short history in September 2021, when it executed an earn-in agreement with NGM with respect to its Swift project, located in the Cortez district of the Battle Mountain – Eureka Trend. NGM committed to spend US$20 million over the next five years (US$4 million of which is guaranteed) to earn an initial 60% interest in the project and they will have further options to increase their interest to 75% by completing additional work commitment milestones and electing to cover Ridgeline’s portion of future mine development costs. “This is a substantial commitment even for NGM, which speaks to the confidence they have in Swift and the potential for this asset as a world-class exploration target,” expressed Chad Peters.
"We have a broad and clear strategy for the next 24 months to achieve a multimillion-ounce resource base, which we are setting up today with our 27,000 m drill program. This is not only to continue to add ounces to our resource, but also to prove that all our 32 targets have large potential."
Antonio Canton, President and CEO, Gold Springs Resource
Adjacent to NGM’s operating Phoenix-Fortitude mine lies Golden Independence’s Independence project. In December 2021, the company released a PEA outlining production of 195,443 oz gold 1.3 million oz silver over a 6.1 year mine life. The PEA estimates an after-tax NPV5 of US$35 million and IRR of 18% using US$1,700/oz gold and US$24/oz silver. To advance the Independence project towards a production decision, the company announced in December 2021 the creation of a joint venture with Americas Gold Exploration Inc. “The project has world class potential that we need help unlocking, but also has the potential for near term cash flow from the heap leach project,” commented Christos Doulis, CEO of Golden Independence.
On the tail end of the Cortez Trend, sits American Eagle Gold’s (AEG) Golden Trend asset. What made the project so appealing to AEG is its position just south of Goldrush. In September 2021, AEG started an initial drill program of 3-4 holes totalling approximately 3,000 m. Exploration is focusing on intersecting lower plate rocks, structures and alteration indicating the presence of a Carlin-type system.
The newest gold explorer at the Battle Mountain - Eureka Trend is Westward Gold, which has assembled a 3,000-hectare land package comprising the Toiyabe project and the Turquoise Canyon project. Since the summer of 2021, the company has used hyperspectral imaging to analyze the old core from the historic operators. They also did a hyperspectral fixed-wing airborne survey and completed a 17-km induced polarization survey across both properties. All the data collected is being incorporated into a new 3D model. The company started 2022 by announcing its listing on the OTCQB Venture Market.
"Golden Independence’s priority in the near term is to begin unlocking the value of the skarn via a partnership with a more senior mining company or alternatively to continue advancing the heap leach portion of the project towards a production decision."
Christos Doulis, CEO, Golden Independence Mining Corp.
Walker Lane Trend
Nevada’s Walker Lane gold trend offers significantly higher grades. Explorer Newrange Gold is targeting the potential near-surface oxide gold resource located at its Pamlico project.
Vancouver-based explorer Gold79 Mines is also developing a trio of properties in the Walker Lane trend. The company is working to leverage an existing database of historical information generated on Gold Chain, its flagship project – located 7.5 km from Kinross Gold’s Round Mountain mine. Gold79 Mines is also developing the Tip Top gold project, which, after the new staking to cover the large alteration footprint, now comprises 139 unpatented mining claims including several low-sulfidation oxide-gold-silver epithermal veins located in the Walker Lane gold trend.
In addition to gold, the Walker Lane Trend also offers significant silver potential, and Nevada Silver Corporation is poised to take advantage of this opportunity. The company started trading on the TSXV in May 2021, listing via a reverse takeover. Its flagship Corcoran Silver project, a silver plus gold project, presents mineralization near surface, is open in all directions and has a NI 43-101 inferred mineral resource of 33.5 million silver-equivalent ounces. “We are the first company in a long while that is adequately skilled and funded to give the project a real opportunity for success,” stated Gary Lewis, group CEO.
"For a company with our market cap to have secured 3,000 hectares on-trend and surrounded by majors in Nevada is no small feat, and a great foundation on which to build. We are excited to carry out methodical exploration programs to expand the known resource at Toiyabe and drill the first holes at Turquoise Canyon."
Colin Moore, President, Westward Gold
Away from the trends
Gold Springs Resource is targeting the eastern edge of the prolific Great Basin, an area between Nevada and Utah. “This area had been neglected through the different exploration booms,” explained Randall Moore, executive vice president of exploration.
In 2020, the company updated the PEA of its single project Gold Springs including an IRR of 40% and an NPV of US$180 million, considering the US$1,800/oz at that time. It also showed a low capex, technically simple, heap leach operation. “We plan to achieve a multi-million-ounce resource base, which we are setting up today with our 27,000 m drill program,” stated president and CEO Antonio Canton.
Nevada’s exploration companies are relying on experienced teams, new exploration technologies, and rethinking the geology of previously mined areas to try to reverse the downward trend in discoveries that has been affecting Nevada since the 1990s.
Image courtesy of Newrange Gold Corp.