A vast fragment of a lost continent lies buried beneath the eastern US, stretching along the Appalachian Mountains from Maine to Georgia, according to new research.
Scientists say the structure formed about 200 million years ago during the breakup of the supercontinent Pangaea. Intense volcanic activity created new crust, which was later buried under sediments from eroding mountains. Researchers describe it as part of a “lost continent” that no longer exists at the surface.
Mapping a hidden continent
The feature, known as the Piedmont Resistor, was identified using data from the Magnetotelluric (MT) Array. The project used about 1,800 temporary stations across the country to measure how deep rocks conduct electricity.
The research, published in Reviews of Geophysics, marks the completion of a two-decade effort. The project began within the U.S. Array, funded by the National Science Foundation.
Unlike seismic surveys, which track rock density, MT methods detect electrical signals deep underground. These signals are influenced by natural changes in Earth’s magnetic field, allowing scientists to map structures far below the surface.
Revealing how the continent formed
The 3D images offer a detailed view of North America’s hidden structure. They show water being pulled into the Cascadia Subduction Zone, where oceanic crust sinks beneath the continent.
The data also reveal stretching in Nevada’s Basin and Range Province and show how Utah’s Wasatch Mountains limit that movement.
In the central United States, researchers mapped buried mountain belts beneath the Great Plains and identified boundaries between ancient crustal blocks. Farther east, those boundaries are less clear. Paul Bedrosian said this suggests the region formed from a mix of continental fragments and volcanic island chains.
A buried relic with modern risks
The Piedmont Resistor stands out as a key remnant of this lost continent. It was not detected in earlier seismic studies. Researchers believe it formed during volcanic eruptions tied to the breakup of Pangaea. Alexander Grayver said the finding is consistent with known geological processes.
A lost continent fragment is hiding beneath the eastern United States.
Scientists have uncovered a massive buried crust stretching from Maine to Georgia—formed during the breakup of Pangaea 200 million years ago. pic.twitter.com/uRxOiR6pUb
— Tom Marvolo Riddle (@tom_riddle2025) May 5, 2026
The structure also affects modern infrastructure. During solar storms, disturbances in Earth’s magnetic field can generate electrical currents in the ground. The dense rocks of the Piedmont Resistor resist these currents, pushing them into shallower layers closer to power systems.
Anna Kelbert said geological conditions can amplify these risks by up to 1,000 times. She warned that many utilities still rely on outdated hazard data.
Implications for resources and research
The findings may help guide the search for critical minerals. Graham Heinson said deposits often form near ancient magmatic systems that MT data can trace.
Despite its scale, the project cost about $20 million. Adam Schultz said the results deliver high value for the investment.
Researchers say the MT Array sets a global standard for imaging Earth’s interior. It also reveals how fragments of a lost continent still shape the land and risks seen today.
