Last day of the dinosaurs' reign captured in stunning detail
Rocks from deep inside the Chicxulub impact crater show what happened in the minutes to hours after one of our planet’s most catastrophic events.
5 Minute Read
By Maya Wei-Haas
PUBLISHED September 9, 2019
Inch by inch, the team pulled up the skinny core of ghostly white limestone from the ocean floor, gazing at the compressed remains of ancient organisms that died tens of millions of years ago. But then a stark divide appeared as the layers abruptly darkened.
“It was nothing like the stuff above,†recalls Sean Gulick, a co-chief scientist of the expedition and a researcher at the University of Texas at Austin.
This change in the rock marks one of the most catastrophic events in Earth’s history, some 66 million years ago, when an epic asteroid slammed into the sea just offshore of Mexico’s Yucatán Peninsula. The impact triggered a nightmarish sequence of events that sent some 75 percent of plant and animal species spiraling to extinction—including all the nonavian dinosaurs.
Now, by subjecting the rocky core to a battery of tests, including geochemical study and x-ray imaging, the research team has assembled a meticulous timeline chronicling events on that fateful day—sometimes down to the minute. As they report today in the Proceedings of the National Academy of Sciences, the dark layers reveal stunning details, including the sheer amount of material that piled up mere hours after the strike, along with bits of charcoal later left by raging wildfires.
“They can put their fingers on moments in that event,†says Jennifer Anderson, an experimental geologist who studies impact cratering at Winona State University. “The level of detail kind of blows you away.â€
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https://www.nationalgeographic.com/science/2019/09/last-day-dinosaurs-reign-captured-stunning-detail/https://www.nationalgeographic.com/science/2019/09/last-day-dinosaurs-reign-captured-stunning-detail/
