The study explains the formation of the US East Coast during the breakup of the supercontinent Pangea

A recent study published in Journal of Geophysical Research: Solid Earth Shedding new light on the formation of the East Coast of the Americas – a geologically „passive edge” during the breakup of the supercontinent Pangea and the opening of the Atlantic Ocean 230 million years ago.

In geology, passive margins are „quiet” areas where land meets the ocean, where there is little faulting or magmatism. Understanding their formation is important for several reasons, including that they are stable regions from which hydrocarbon resources are extracted and that their sedimentary archive preserves our planet’s climate history going back millions of years.

The study, co-authored by University of New Mexico scientists, SMU seismologist Maria Beatrice Magnani, and scientists from Northern Arizona University and USC, examines the structure and volume of magma-derived rocks along the East Coast. This is linked to how the continents split up when Pangea broke up. This event may also have influenced the formation of the Mid-Atlantic Ridge, a vast underwater mountain system that runs through the center of the Atlantic Ocean.

Using special instruments called sea-floor seismographs, the research team examined the rocks at a depth of about 10 to 20 kilometers. The instruments measure the speed of sound in rocks beneath the surface, which helps scientists determine the composition and type of rock. The research is part of a larger effort to investigate how the continents broke up, one of the most important questions in Earth science.

„Passive edges define most of Earth’s coastlines and most of the world’s population,” Magnani said. „They are vulnerable to changes caused by long-term climate variability and sea-level rise. Understanding their origins and the processes that shape them provides clues to how they may be affected and respond to geohazards, including earthquakes, submarine landslides, and erosion.”