A research team has discovered significant evidence of a catastrophic asteroid impact that occurred approximately 35 million years ago in North Carolina. This event, which originated from an asteroid striking the Atlantic Ocean near present-day Cape Charles, Virginia, unleashed devastating consequences across a vast region. The findings, published in the journal Southeastern Geology, reveal geological layers indicative of the impact and the subsequent tsunami that ensued.
The asteroid, estimated to be around 3 miles wide (5 kilometers), created one of the largest impact craters buried beneath the waters of Chesapeake Bay. The crater was first identified in 1990, and scientists have since been piecing together the aftermath of the collision. The new research, based in Moore County, North Carolina, extends the understanding of the asteroid’s reach, with evidence located approximately 240 miles (386 kilometers) from the Virginia site.
Geological Discoveries in North Carolina
The investigation led by geologists involved the examination of distinct rock layers within a one-yard-thick formation in Moore County. They identified four separate beds of rock, each showcasing unique characteristics linked to the ancient impact.
The first layer, about 17 inches thick (43 centimeters), consists of sandy clay enriched with carbon glass and rock fragments. Notably, this layer contained between 14 to 18 parts per billion of iridium, a rare element commonly associated with meteorites. The second layer, only around 3 inches thick (9 centimeters), featured silt and quartz masses, along with 2 to 6 parts per billion of iridium. The third bed, measuring approximately 2 inches thick (6 centimeters), was a blend of soil and seafloor fragments. Finally, the fourth layer, around 6 inches (15 centimeters) thick, is composed of coarse sand, likely deposited by the tsunami triggered by the asteroid’s impact.
These findings paint a vivid picture of the geological consequences of the impact, which destroyed ecosystems for hundreds of miles and released molten debris from Massachusetts down to Barbados.
The Tsunami’s Legacy
When the asteroid struck Earth, it generated a hypersonic shock wave that obliterated plant and animal life in its vicinity. Scientists had long theorized that this event triggered a massive tsunami, but until now, tangible evidence had been lacking. The new study confirms that the unique rock formations in North Carolina trace back to the moment of the impact and the tsunami that followed.
The first rock bed documents the initial impact, rich with ejecta and carbon-laden debris. The second layer represents an accumulation of finer particles ejected as the shock plume dissipated. The third bed captures the inland surge of seawater and sediment, while the fourth signifies a period when the channel refilled with clean sand and gravel.
These insights enhance the understanding of the Chesapeake Bay impact and its extensive effects on the surrounding environment. The researchers emphasize the importance of this single asteroid event in reshaping an entire region millions of years ago.
As scientists continue to study these ancient geological formations, they gain valuable insights into the complex interactions between celestial events and Earth’s ecosystems. The findings not only deepen our understanding of the past but also underscore the profound influence of asteroids on the planet’s geological history.