North Carolina experienced massive tsunami during late Eocene due to extraterrestrial impact: Researchers say

Analysis of North Carolina’s Sandhills has provided experts with a glimpse into the region’s intriguing period. They looked into the distinct layers of the landform present on a hillside in Moore County and concluded that the area was once hit by an extraterrestrial object. Findings regarding this strike were published in the journal OES Faculty Publications. The investigation also revealed the events that followed, and one of them was determined to be a tsunami. The area of investigation is situated in a shallow channel, carved into older Eocene sands and clays. 

Secrets of Mount Helicon Formation

The investigated layers in the channel have been named Mount Helicon Formation by experts, according to Earth.com. The extraterrestrial event observed in the layers could be the consequence of a late Eocene bolide impact, which refers to a strike by a comet or fast-moving meteor that arrived on Earth 30 to 40 million years ago. Lead author G. Robert Ganis, a consulting geologist, shared that all the observations regarding the extraterrestrial strike and tsunami arrived from a one-yard-thick sequence at Paint Hill. In total, this sequence contained four distinct beds that carried both impact debris and tsunami deposits. 

Further investigation at Paint Hill began at the behest of the past owner, who wanted to construct a pipeline on the property, according to the Virginia Mercury. Ganis was the first one at the site and was immediately shocked to see the deposits 10 feet deep, as they did not align with the geological insight available about the region. The sediment layers in the area were dated to the late Eocene period with the help of shark teeth detected nearby. After analysis, Ganis and his team concluded that they were actually tsunami deposits left by a late Eocene meteorite strike in Virginia. At present, Paint Hill is in the custody of the nonprofit Nature Conservancy, which has promised to preserve the tsunami deposit.

Association with Chesapeake Bay Impact Crater

The bolide, which caused the impact debris, also facilitated the Chesapeake Bay impact crater, uncovered in the 1990s. Experts believe that at that time, the present-day southeastern Virginia must have been underwater, and teeming with diverse marine creatures, like ancient whales, sharks, and sea stars. The 2 to 3 miles wide bolide must have destroyed these lifeforms within seconds as it arrived at a pace of 44,000 miles per hour. As per estimates, the extraterrestrial object landed in the lower part of the Chesapeake Bay. 

“There was a kill zone that would have been several hundred miles out in every direction,” said Rich Whittecar, a geologist and emeritus professor at Old Dominion University. Whittecar speculates that the resultant blast traveled faster than sound and carried more explosive power compared to average atomic bombs. There was no way plants and animals sustained the damage and heat brought by this blast. However, the strike is already considered the largest known bolide strike in the U.S.; the evaluation conducted in the study is the first time that the far-reaching consequences of this strike have been documented. 

Tsunami Triggered by the Strike

The asteroid triggered a tsunami 240 miles away from the crater in the Sandhills of North Carolina. Ganis claims that the asteroid landed in water and caused a big splash, resulting in a tsunami thousands of feet high in elevation. Such a tsunami is rare even in the present-day environment, which might have taken over the Blue Ridge Mountains and also swept the Southeast, including the Atlantic Ocean. Such a wide-reaching tsunami was speculated through the impact crater, but this is the first time remains of it have come forward. 

For long, experts believed that Paint Hill Rock formation could be the result of a tsunami, and therefore focused specifically on its layers. Upon a closer look, they detected charcoal, natural glass, and other rock fragments in the bottom layer. Such materials fly out when a place is hit by a bolide, implying that the area could have been affected by a tsunami triggered by the late Eocene bolide impact. There were also traces, reflecting that a tremendously hot blast had affected the region. Another layer carried ash possibly from the Eocene explosion. 

Researchers also detected plinthite at the top layer. Plinthite is a red-colored and iron-rich material commonly found in tropical regions. The material could have been swept by the tsunami from the tropics and deposited at Paint Hill. There was also iridium in the sediment, typically found in asteroids. All these evidences together imply that an extraterrestrial strike facilitated a tsunami in the region in the late Eocene period.