CRITICAL MINERALSCritical Minerals Repositories Discovered in Northern Maine

A team of state and federal scientists have discovered an area in northern Maine that is high in critical mineral resources, highlighting for the first time the importance of this region to the U.S. mineral resource economy.

The team’s findings are described in a new publication by scientists from the University of Maine at Presque Isle, U.S. Geological Survey (USGS), and the Maine Department of Agriculture, Conservation and Forestry’s Maine Geological Survey (MGS).

The elements were found in rocks in the vicinity of Pennington Mountain, a remote peak in central Aroostook County, about 40 miles northwest of Presque Isle, Maine. The discovery included rare earth elements, niobium, and zirconium, which are important for electronics, defense, and manufacturing applications.

This research was conducted as part of the USGS’s Earth Mapping Resources Initiative project, a partnership between the USGS and state geological surveys to modernize our understanding of the nation’s fundamental geologic framework and mineral resources through new geologic maps, geophysical and topographic surveys, and geochemical sampling. Earth MRI aims to identify areas with potential for undiscovered critical mineral deposits that could reduce U.S. mineral import dependence, thereby strengthening national security, creating jobs within the private sector, and generating ancillary economic and social benefits.

Bipartisan Infrastructure Law funding has accelerated this new mapping in areas with potential for hosting critical mineral resources both still in the ground and occurring in mine wastes. Funding was also provided by the USGS National Cooperative Geologic Mapping Program through its STATEMAP project. While analyzing the survey data, USGS research geophysicist AnjiShah found an anomaly: a geological feature that looked similar to others that contain rare earth elements and other critical mineral resources.

“This is really exciting scientifically,” said Shah. “As we were examining the data, all of a sudden, this feature caught my eye. I knew immediately we had something special here.”

“The project has resulted in rewriting of the geologic and tectonic history of the region, and the Earth MRI airborne geophysical survey greatly helps the bedrock mapping and assessment of mineral potential,” said Chunzeng Wang, lead author of the paper and professor of earth and environmental sciences at the University of Maine at Presque Isle. “It is truly excellent teamwork. The level of support and cooperation by the USGS, the MGS, and my university is unprecedented.”