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Rare Earths and Critical Minerals in the North American Cordilleran Alkaline-Igneous Belt: A Real Opportunity or Geological Hype?

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Highlights

  • The North American Cordilleran alkaline-igneous belt contains diverse critical minerals like gold, molybdenum, and rare earth elements.
  • The belt spans across southern Colorado, New Mexico, Texas, and Mexico.
  • While some deposits show promising concentrations of rare earth elements, there are significant economic and technical barriers, including complex processing and infrastructure challenges.
  • Developing these mineral sources is strategically important for U.S. critical material security.
  • This development aims to reduce dependence on China’s dominant rare earth supply chain.

A recent study led by Virginia T. McLemore (opens in a new tab) and colleagues from the New Mexico Bureau of Geology and Mineral Resources (opens in a new tab) explores the diverse critical mineral deposits within the North American Cordilleran alkaline-igneous belt, which spans southern Colorado, New Mexico, Texas, and Mexico. This region, formed by Eocene-Miocene magmatic activity (45.6 to 22.8 Ma), contains a variety of mineralization types, including alkalic-type epithermal gold, Climax-type porphyry molybdenum, and magmatic rare earth element (REE) deposits. The study highlights both opportunities and challenges in developing these resources.

The Geological Potential and Economic Challenges of Rare Earth Deposits in the North American Cordilleran Alkaline-Igneous Belt

The North American Cordilleran alkaline-igneous belt holds a diverse range of critical mineral deposits, including gold, molybdenum, rare earth elements (REE), tellurium, fluorine, zirconium, and niobium.  The region was recently covered in the Lyell Collection. (opens in a new tab)

Some of these minerals have already been historically mined, demonstrating at least partial economic feasibility. In terms of REE content, certain Gallinas Mountains (opens in a new tab) samples contain up to 8% total REE, while Cornudas Mountains (opens in a new tab) samples reach 3110 ppm, mostly in eudialyte. These concentrations exceed standard cutoffs for economically viable mining projects, positioning the region as a promising domestic source of rare earths. Additionally, advanced processing techniques could make these deposits more viable, as REE-bearing minerals such as eudialyte, zircon, monazite, and bastnäsite can be concentrated via magnetic separation before undergoing leaching to extract valuable elements.

Past mining success in tungsten, gold, and molybdenum further validates the region’s potential, proving that economic extraction of certain minerals has already been achieved. Beyond resource viability, the geopolitical relevance of these deposits is significant. With China maintaining a dominant position in the global rare earth supply chain, developing U.S. domestic sources is a strategic priority for securing critical materials for defense, energy, and high-tech industries.

Despite these advantages, major economic and technical barriers exist.

Many ofthe deposits have only anomalous (non-economic) concentrations of REE,tellurium, tungsten, and beryllium, meaning that while the minerals are present, they may not be economically extractable under current market conditions. Moreover, even high-grade deposits require complex processing due to the presence of REEs in intricate mineral forms such as eudialyte, roumaite, and calcio-catapleiite. These minerals demand specialized and expensive extraction technologies, further complicating the cost-effectiveness of mining operations.

Another major hurdle is the remote location and infrastructure challenges of many of these deposits. Some are found in geologically and environmentally sensitive areas, making them difficult to access and requiring significant infrastructure investment before mining can become a reality. Compounding the issue, the study does not confirm proven reserves, as few of these deposits have been systematically drilled and assessed using modern resource estimation techniques. Without this validation, investor confidence and long-term planning remain uncertain.

Environmental and regulatory challenges would add to the complications. Many of these mineral-rich areas fall within protected or environmentally sensitive lands, making the permitting and development process politically and legally contentious. Additionally, the REE market is highly volatile, and China’s history of price manipulation and supply chain dominance has previously disrupted Western efforts to develop alternative sources. If China were to flood the market with low-cost rare earths, U.S. mining projects could quickly become uneconomical, regardless of resource availability.

Bottom Line, Risky Picture for Investment

The North American Cordilleran alkaline-igneous belt presents both promise and uncertainty in the realm of critical mineral development. Some locations, particularly Gallinas and Cornudas Mountains, display higher economic potential, but the region as a whole faces significant hurdles in terms of resource validation, processing complexity, infrastructure needs, and geopolitical risks. While this belt may play a future role in U.S. critical mineral security, substantial investment, technological advancements, and market stability will be necessary before these deposits can become competitive with existing global suppliers.

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