First day of dinosaur extinction recorded in rocks at asteroid impact site

Researchers probing the impact that wiped out the dinosaurs find evidence of wildfires and tsunami in the rocks at ground zero. An international team led by University of Texas and including Imperial College London researchers analysed more than 130 metres of rock that had built up over just one day - the day after the asteroid struck. At least 325 billion metric tons of sulphur would have been released by the impact. That's about 10,000 times more than the amount of sulphur released during the 1883 eruption of Krakatoa Professor Joanna Morgan By analysing the rocks, they found evidence that a resurging ocean and tsunami swept material back into the crater formed by the asteroid. They also found charcoal from wildfires, which along with soot, sulphur and dust blasted into the atmosphere, blocked the sun and caused global cooling. This scenario has long been suggested by scientists investigating why the dinosaurs, and 75 per cent of all life on Earth, were wiped out by the asteroid - but this is the first direct evidence from the crater itself. The team's results are published today in Proceedings of the National Academy of Sciences .