A team of geologists has uncovered significant evidence linking an ancient asteroid impact to geological formations in North Carolina, potentially revealing details about a catastrophic event that occurred approximately 35 million years ago. The asteroid, traveling at around 40,000 miles per hour (64,373 kilometers per hour), struck the Atlantic Ocean near present-day Cape Charles, Virginia, creating a massive impact crater that lies buried half a mile beneath the Chesapeake Bay.
The Chesapeake Bay crater, discovered in 1990, is one of the largest and most well-preserved impact sites on Earth. Recent research published in the journal Southeastern Geology has provided insights into the far-reaching consequences of this collision, including evidence of a tsunami that followed the impact. The study highlights findings from a location approximately 240 miles (386 kilometers) south of the Virginia crater, in the Sandhills of Moore County, North Carolina.
Geological Discoveries in Moore County
At the site in Moore County, the researchers identified four distinct layers of rock within a single formation measuring around one yard thick. The first layer, approximately 17 inches (43 centimeters) thick, consists of sandy clay infused 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, around 3 inches (9 centimeters) thick, featured silt and quartz, along with 2 to 6 parts per billion of iridium. The third layer included a mix of soil and seafloor fragments, measuring about 2 inches (6 centimeters), while the fourth layer, roughly 6 inches (15 centimeters) of coarse sand, is thought to have been deposited by the tsunami triggered by the asteroid’s impact.
The unique geological characteristics of these layers puzzled the researchers until they connected them to the ancient asteroid strike. This discovery underscores the profound impact of the asteroid on the region, extending its influence beyond the immediate vicinity of the crater.
Impact and Tsunami Evidence
When the asteroid collided with Earth, it generated a hypersonic shock wave, devastating ecosystems for hundreds of miles around. The event released vast amounts of molten debris, affecting areas from Massachusetts to Barbados. Initially, scientists speculated about the possibility of a tsunami resulting from the impact but lacked concrete evidence until now.
The findings in North Carolina illustrate how the geological layers correspond to key moments following the impact. The first bed of rock captures the immediate aftermath, characterized by ejecta and carbon-rich debris. The second layer represents finer particles ejected as the impact plume began to dissipate. The third layer documents the inland surge of seawater and sediment, while the fourth layer reflects the subsequent refilling of the channel with clean sand and gravel.
This research not only sheds light on the catastrophic consequences of the asteroid impact but also enhances our understanding of the geological history of the Chesapeake Bay region. As scientists continue to explore the implications of these findings, they are gaining a clearer picture of how a single cosmic event reshaped a significant portion of the Earth’s landscape millions of years ago.
