The impact of carbon dioxide on dinosaur extinction is overestimated. This is what VUB geologists say after an initial measurement of the temperatures from the Chicxulub meteorite crater in Mexico.
The Chicxulub crater is known as the site of the meteorite impact at the end of the Cretaceous geological period. The meteorite impact heralded the end of the dinosaurs 66 million years ago. Today, the crater is a place for many scientists to study the geological processes that take place after a meteorite impact on Earth.
The impact of a meteorite impact is so great that most natural material evaporates within seconds. A few minutes later, according to VUB geologist Pim Kaskes, chunks of limestone and lime minerals appear. By using a chemical technique he was able to determine what temperature was needed to form such lime minerals.
Calcite crystals
The high temperature and intensity of the shock from a meteorite impact forms calcite crystals within the crater, a result of a chemical reaction with carbon dioxide and limestone that litters the crater’s surroundings. “The intense shock of the meteorite impact caused the limestones to release carbon dioxide, but much of the carbon remained inside the crater. There it was able to form such calcite crystals with highly reactive quicklime,” says Kaskes.
The conclusion is that the majority of the carbon dioxide is still within the crater. According to Kaskes, the consequences of the impact nevertheless remained disastrous. “Our findings open many new possibilities for future research because we can now also apply this method to rocks from other impact craters around the world,” Kaskes concludes. His study was published in the journal ‘Proceedings of the National Academy of Sciences (PNAS) Nexus’.
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