AsianScientist (Dec. 6, 2016) – The impact of large asteroids millions of years ago could have deformed rocks in such a way that creates environments conducive to early life, according to research published in Science.
Around 65 million years ago, a massive asteroid crashed into the Gulf of Mexico, causing the Chicxulub impact. It was so huge that the blast and subsequent knock-on effects wiped out around 75 percent of all life on Earth, including most of the dinosaurs.
Understanding the formation process of the Chicxulub crater is critically important to estimating the released energy from the impact and the causative environmental changes that triggered mass extinction. However, because the crater is filled with a few hundred meters worth of thick, post-impact carbonates, drilling is necessary to obtain impact-related sediments.
The scientists from Imperial College London in the UK and Tohoku University in Japan studied samples from the rocky inner ridges of the crater, known as the ‘peak ring,’ to understand more about the ancient cataclysmic event. Analysis of the core samples revealed that the ancient impact deformed the peak ring rocks in such a way that it made them more porous and less dense than any models had previously predicted. Porous rocks provide niches for simple organisms to take hold, and there would also be nutrients available in the pores, from circulating water that would have been heated inside the Earth’s crust.
Hence, from studying the Chicxulub crater in the Gulf of Mexico, the researchers inferred that the impact of large asteroids must have also deformed rocks in a way that may have produced habitats for early life.
“It is hard to believe that the same forces that destroyed the dinosaurs may have also played a part, much earlier on in Earth’s history, in providing the first refuges for early life on the planet. We are hoping that further analyses of the core samples will provide more insights into how life can exist in these subterranean environments,” said lead author Professor Joanna Morgan from Imperial College London.
The article can be found at: Morgan et al. (2016) The Formation of Peak Rings in Large Impact Craters.
Source: Tohoku University; Photo: International Ocean Discovery Program.
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