Uncovering America’s Hidden Treasure: Rare Earth Elements Discovery in Maine’s Forests

In a remote region of northern Maine near Pennington Mountain, scientists from the U.S. Geological Survey (USGS) have found rocks rich in rare earth elements, niobium, and zirconium.

These elements are crucial in various technologies, such as smartphones, wind turbines, and electric vehicle motors.

Currently, only one site in the United States mines rare earths.

This discovery could potentially mark the location of the next big deposit of these critical elements, although further surveys are needed to confirm this.

Earth MRI: Mapping America’s Critical Mineral Resources

The USGS and state geological surveys have joined forces to create the Earth Mapping Resources Initiative (Earth MRI), which aims to improve America’s knowledge of its critical mineral resources.

Established in 2019, Earth MRI received a significant funding boost in 2021 through the Bipartisan Infrastructure Law, enabling the launch of numerous new critical mineral-mapping efforts from Alaska to the Great Plains.

With less than 40% of the nation mapped in enough detail to support the discovery of new mineral deposits, Earth MRI seeks to fill this gap and support the Biden administration’s plan to boost domestic mining of rare earths and lithium.

To achieve this, the USGS is using aeromagnetic surveying and radiometric surveys to measure specific properties of rocks, while state geologists conduct detailed surface mapping and sampling.

Exciting Discoveries in Maine’s Geological Landscape

The discovery of rare earth elements, niobium, and zirconium near Pennington Mountain in Maine was made during an Earth MRI project that involved the USGS, the University of Maine at Presque Isle, and the Maine Department of Agriculture, Conservation and Forestry’s Maine Geological Survey (MGS).

The geologic feature was identified through surveys flown by aircraft, which measured variations in Earth’s magnetic field and natural low-level radiation.

Upon noticing the unusual feature in the data, USGS scientists collaborated with Professor Chunzeng Wang from the University of Maine-Presque Isle, who collected rock samples and sent them for geochemical analysis.

The results showed that the rocks were significantly enriched in rare earth elements and several trace metals.

This exciting finding highlights the importance of new evaluations for potential critical mineral resources based on integrated studies involving geophysics, geology, and geochemistry.

Balancing Mineral Extraction with Social and Environmental Factors

As the USGS discovers more mineral deposits through Earth MRI, careful consideration must be given to the potential social and environmental impacts of mining.

Experts suggest that combining maps of mineral deposits with maps showing biodiversity, water resources, historically marginalized communities, and Indigenous lands can help minimize harm when permitting new mining.

One possible solution is to explore abandoned mine land, which has already been degraded, for energy transition metals.

For example, coal mining waste can be enriched in rare earth elements, and extracting these metals may even contribute to environmental cleanup efforts.

Article In a Snapshot

• Scientists from the U.S. Geological Survey (USGS) discovered rocks rich in rare earth elements, niobium, and zirconium near Pennington Mountain in northern Maine, which could potentially be a new significant deposit of these critical elements.
• Earth Mapping Resources Initiative (Earth MRI) is a collaborative effort between the USGS and state geological surveys to improve America’s knowledge of its critical mineral resources and support domestic mining of rare earths and lithium.
• The discovery in Maine was made through integrated studies involving geophysics, geology, and geochemistry, emphasizing the importance of such evaluations for uncovering potential critical mineral resources.
• Balancing mineral extraction with social and environmental factors is crucial, and combining maps of mineral deposits with maps showing biodiversity, water resources, and Indigenous lands can help minimize harm when permitting new mining.
• Exploring abandoned mine land for energy transition metals, such as coal mining waste enriched in rare earth elements, can contribute to environmental cleanup efforts while simultaneously addressing resource demands.