by Aberdeen scientists
Scientists at the University of Aberdeen have discovered evidence in south west Britain of a massive prehistoric explosion that scattered debris across the British Isles. The explosion seems to have been caused by an asteroid hitting the Earth 214 million years ago.
Samples of the material have been tested by researchers at the University of Aberdeen and the Open University who confirm that this is the first recorded example of such an impact deposit in Britain. Dr Gordon Walkden of the University of Aberdeen, leader of the international research group, said: “We have found evidence of a massive shock wave carrying molten rock and dust that has left a thin layer of glass beads and shattered mineral grains across the ancient British land surface.” Dr Simon Kelley of the Open University dated the impact material.
Dr Walkden and his team discovered the material in sediments near Bristol and explained: “There is only a thin layer that has been preserved in sediments of the late Triassic age but this shows stresses well beyond the reach of a nuclear bomb. These stresses could only have been produced by a massive explosion caused by an asteroid colliding with the earth. A similar catastrophe is believed to have killed off the dinosaurs just 65 million years ago.”
It is believed that this new discovery is linked to a giant impact crater discovered some years ago in Manicouagan in North East Canada. Due to the earth’s plates moving, Manicouagan would have been much nearer to Britain in the Triassic period than it is today. Manicouagan is one of the best known terrestrial impact craters and is a silent witness to a major catastrophe. The object causing the crater is likely to have been a chunk of rock over three miles across. Dr Walken added: “The shock wave causing this crater would have been at least 40 million times larger than the Hiroshima blast and would have carried molten rock and dust thousands of miles. It is this material that we have found.”
Dr Matthew Genge, meteorite expert and lecturer at Imperial College London, said: “This is perhaps the most exciting and best spherule layer discovered since the dinosaur-killing K/T layer and it is amazing to think that it lay hidden for so long under the green fields of south west England. If it wasn’t for Gordon Walkden’s dogged persistence and sharp eye for something out of the ordinary, this exciting discovery may never have been made.”
A sample of the material discovered by Dr Walkden will be on display at the Darwin Centre at the Natural History Museum, London on Friday (November 15) at a public event in which Dr Walkden will be speaking. A live webcast of the event will also take place. Pieces of the material will also be on display at the National Space Centre in Leicester, the National Museum of Scotland, Edinburgh and at the University of Aberdeen.
Further research into the timing and effects of the impact will continue, following a £30,000 grant from the National Environment Research Council. Dr Walkden’s findings will be published this week by the international journal Science and the American Association for the Advancement of Science, within the Science Express website.