Asteroid impact, not volcanic eruptions, killed the dinosaurs

Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs and about 75 per cent of Earth's species 66 million years ago, according to a team involving UCL and University of Southampton researchers. Two planetary-scale disturbances occurred within less than a million years of one another, leading scientists to question the role each played in driving the mass extinction event: An asteroid more than 10 km in diameter collided with the Yucatan Peninsula in Mexico creating the 200 km wide Chicxulub impact crater and around the same time about 500,000 km3 of lava flooded across much of India and into the deep sea forming the Deccan Traps, one of the largest volcanic features on Earth. In a Yale-led study, published today in  Science , analysis of marine fossils and climate models shows that the major release of volcanic gasses, thought by some to contribute to the extinction, happened about 200,000 years before the asteroid impact, making the asteroid the sole driver of the extinction event. "Most scientists acknowledge that the last, and best-known, mass extinction event occurred after a large asteroid slammed into Earth 66 million years ago, but some researchers suggested volcanic activity might have played a big role too and we've shown that is not the case," explained co-author, Professor Paul Bown (UCL Earth Sciences). The researchers searched for evidence for a correlation in timings between volcanic eruptions and the mass extinction event, known as K-Pg, and found none.