Appalachian Transect Airborne Magnetic and Radiometric Survey

Geophysical surveys that sense the magnetism and radiation of bedrock were flown in Maryland, Pennsylvania, and West Virginia by planes such as the one below (photo on left) in 2022-2023. 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 right).

Data from these surveys will be used by MGS for surface and subsurface geologic mapping. Variations in magnetization and natural radioactivity occur due to differences in rock type, soil cover, and mineral content, and assist in determining the location of geologic contacts, mineralized zones, and structural features such as faults and folds (Shah et al., 2025). Data from these surveys was released in September, 2025, and is available at the following link: https://doi.org/10.5066/P14AFABN

Overview of the flight region and data collected for this survey. Magnetic data is shown on the left with a color gradient of magnetic anomaly from low (blue) to high (red). Radiation data is shown on the right with radioactive elements in different colors:
Potassium (K) are reds, Thorium (Th) are greens, and Uranium (U) are blues.

References
Shah, A. K., D. H. Doctor, C. Gustafson, and A. D. Pitts (2025), New maps of natural radioactivity reveal critical minerals and more, Eos, 106, https://doi.org/10.1029/2025EO250370. Published on 7 October 2025.

U.S. Geological Survey, 2025, Airborne Magnetic and Radiometric Survey over parts of Maryland, Pennsylvania, and West Virginia, 2022-2023: U.S. Geological Survey data release, https://doi.org/10.5066/P14AFABN. Published on 2025-09-04.

Contact Information
Christopher P. Williams, Program Chief, Coastal and Environmental
(410) 554-5559 | christopherp.williams@maryland.gov
Rebecca Kavage Adams, Geologist
(410) 554-5553 | rebecca.adams@maryland.gov