Prairie Research Institute


Mineral resources are essential to many advanced technologies that we rely on for national defense, transportation, and the expansion of renewable energy infrastructure. The U.S. is heavily dependent on imports for these important raw materials—often from unstable sources. Therefore, the U.S. Geological Survey (USGS) has designated more than 50 elements and compounds as “critical minerals” and launched the Earth Mapping Resources Initiative to increase knowledge of the domestic distribution and concentration of these commodities.

USGS and state geological surveys are collaboratively identifying and gathering data about the spatial distribution and characteristics of critical minerals across the contiguous U.S. and Alaska. Broad areas of the mid-continent, partly centered on Illinois, show potential for containing multiple critical mineral resources. Geochemical reconnaissance, subsurface mapping, and geophysical surveys are being conducted to locate these resources. Rare earth elements (REEs) are a primary target of multiple projects co-led by the Illinois State Geological Survey, part of PRI.

Rare earth elements and critical minerals

The Illinois Basin carbon ore, rare earth, and critical minerals (CORE-CM) initiative is evaluating the domestic occurrence of strategic elements in coal, coal-based resources, and waste streams from coal use in and around the Illinois Basin. Jointly with this resource assessment, the Illinois Basin CORE-CM is assessing mining techniques, CORE-CM separation technologies, environmental justice considerations, workforce development, and technology innovation that will catalyze a strategic element economy. 

Earth Mapping Resources Initiative

The Earth Mapping Resources Initiative (Earth MRI) aims to improve the knowledge of the geologic framework in the United States and identify areas that may have the potential to contain undiscovered critical mineral resources.

The Earth Mapping Resources Initiative is a cooperative program between the U.S. Geological Survey, Illinois State Geological Survey (ISGS), and other federal, state, and private-sector groups across the country. The program is focused on improving knowledge of the U.S. geologic framework and identifying areas with critical minerals potential. The ISGS is playing a leadership role in regional geochemical reconnaissance studies and participates in the planning and use of new airborne geophysical surveys to advance the development of the nation’s critical minerals economy that will reduce reliance on foreign sources. EarthMRI projects at the ISGS include the Illinois-Kentucky Fluorspar District (especially Hicks Dome), the Wauboukigou Igneous Province, rare earth element-bearing phosphorites, and metalliferous black shales.