Maryland Department of Natural Resources

Earth MRI at MGS

Maryland Geological Survey (MGS) geologists are working in partnership with the U.S. Geological Survey (USGS) Earth Mapping Resources Initiative (Earth MRI) to map mineral resources that are critical to U.S. security and economic prosperity. This work is designed to support the goals of Federal Executive Order 13817 to strengthen and sustain U.S. domestic supply of critical mineral resources.

A few examples of these critical minerals are: rare earth elements (REEs) that we use in cell phones and strong magnets needed for clean energy technology; lithium (Li), used in rechargeable batteries and lightweight aerospace alloy; and manganese (Mn), which is used in the production of steel. The 2022 USGS list of critical minerals can be found here: 2022 USGS critical minerals list.

Earth MRI partners use state-of-the-art geologic mapping and airborne geophysical and topographic (LiDAR) surveys to identify potential buried critical mineral deposits. The Earth MRI program seeks to “improve topographic, geologic, and geophysical mapping of the United States and make the resulting data and metadata electronically accessible”.

The USGS EarthMRI program website can be viewed at:

Geochemical data for EarthMRI sites nationwide can be downloaded from:

plane photo plane equip photo
Geophysical surveys that sense the magnetism and radiation of bedrock are currently being flown in Maryland, Pennsylvania, and West Virginia by planes such as this one. Magnetic data is collected by a magnetometer located at the far end of the long white “stinger” on the back of the plane. Radiation data is collected by a detector located within the body of the plane (photo on left).

The following table includes Maryland quadrangles that have been mapped as part of Earth MRI. Any available maps and GIS data for each quadrangle is available for download under the Formats column.
Quadrangle Author(s) Formats Version
pdf Map jpg Map gis Map data
Blue Ridge Brezinski, D.K., 2021 pdf Map --- gis Map data
Harpers Ferry Brezinski, D.K., and Kavage Adams, R., 2022 --- --- gis Map data Harpers
Keedysville Brezinski, D.K., and Kavage Adams, R., 2022 --- --- gis Map data
Middletown Brezinski, D.K., and Kavage Adams, R., 2022 --- --- gis Map data
Myersville Brezinski, D.K., and Kavage Adams, R., 2022 --- --- gis Map data
Point of Rocks Brezinski, D.K., and Kavage Adams, R., 2022 --- --- gis Map data Point Of

Initiated in 2020, MGS’s Earth MRI program has multiple ongoing projects. Below are some links to relevant pages.

NeoProterozoic Regolith and Rare Earth Elements of the Maryland Blue Ridge (Earth MRI 2020-2021)

Geochemical Sampling and Regional Interpretation (Illinois and Appalachian Basin) of High Alumina Underclay Deposits in the Central and Eastern U.S. (2020-2022)

Mapping Volcanogenic Mineralization: Study of the Westminster Terrane of the Mid-Atlantic Piedmont (2021-2023)


Maryland Geological Survey, October 2022

Contact information
Maryland Geological Survey
Richard A. Ortt, Jr., Director
David K. Brezinski (410) 554-5526