Project to drill into 'dinosaur crater' gets under way

http://www.bbc.com/news/science-environment-35950946

Project to drill into 'dinosaur crater' gets under way

By Jonathan Amos
BBC Science Correspondent

5 April 2016

A joint UK-US-led expedition has got under way to drill into the Chicxulub Crater off the coast of Mexico. This is the deep scar made in the Earth's surface 66 million years ago by the asteroid that scientists believe hastened the end of the dinosaurs. Today, the key parts of the crater are buried beneath 600m of ocean sediment. But if researchers can access its rocks, they should learn more about the scale of the impact, and the environmental catastrophe that ensued.

They are particularly interested in a feature called the "peak ring". This was created at the centre of the impact hole where the Earth rebounded after being hit by the city-sized object. In geophysical surveys that can sense beneath the ocean bed, the ring looks like an arcing chain of mountains.

"We want to know where the rocks that make up this peak ring come from," explained Prof Joanna Morgan, the co-lead investigator from Imperial College London. "Are they from the lower, mid or upper crust? Knowing that will help us understand how large craters are formed, and that's important for us to be able to say what was the total impact energy, and what was the total volume of rock that was excavated and put into the Earth's stratosphere to cause the environmental damage," she told BBC News.
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