The impact of the asteroid that triggered the mass extinction of dinosaurs on Earth also left its mark on North Dakota.
And it’s in North Dakota that scientists are learning about what happened in the minutes and hours after the massive Chicxulub strike in Mexico’s Yucatan Peninsula.
In an article to be published April 1 in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), a dozens contributors across several science fields outline how deposits at a site in North Dakota’s Hell Creek Formation tell the story of an event thousands of miles away that left its mark deep in the North American continent.
By studying indicators of ancient inland water flows and a mix of fossilized Cretaceous period biota, researchers believe within 15 minutes of the Chicxulub impact in Mexico, a massive, 32-foot high surge of water from what was then a continental interior seaway washed across portions of North Dakota, depositing a rich collection of marine life in the Hell Creek Formation.
The wave, known as a “seiche,“ was triggered by seismic waves from the asteroid strike.
In addition to the seiche, debris from the asteroid strike fell from the skies over the Hell Creek area, depositing impact-melt glass, “shocked“ minerals (where the structure of minerals is changed due to sudden, immense pressure) and other materials contaminated with iridium, a radioactive material typically found in asteroids.
The researchers believe most of that debris was deposited within two hours of the asteroid impact.
You can read more about the article, “Prelude to Extinction: a seismically induced onshore surge deposit at the KPg boundary, North Dakota,” and the research April 1 at the PNAS website here.
There have been previous investigations into the impact of the Chicxulub crash on North Dakota.
In 2015, state geologist Ed Murphy wrote about several field research studies going hack to 1981 revealing evidence of a rush of water into the state, along with shocked quartz and other shocked mineral grains, iridium and other atmospheric fallout from the asteroid impact.
You can read that overview here.