It's lucky for the good burghers of Ullapool in Scotland that they weren't around 1.2 billion years ago, because it was around then that the biggest meteorite ever to hit the British Isles would have made a bit of a dent in local house prices.
That's according to the combined forces of the University of Oxford and the University of Aberdeen, who say that "unusual rock formations" previously thought to have volcanic origins are actually the debris ejected from a meteorite strike which threw material over an area 50km across.
The volcanic theory has always had geologists scratching their heads, since there are "no volcanic vents or other volcanic sediments nearby". The researchers moved in for the kill by taking rock samples in 2006, and have now published their revelations in the journal Geology.
Ken Amor of Oxford Uni’s Department of Earth Sciences, explained: "Chemical testing of the rocks found the characteristic signature of meteoritic material, which has high levels of the key element iridium, normally only found in low concentrations in surface rocks on Earth. We found more evidence when we examined the rocks under a microscope; tell-tale microscopic parallel fractures that also imply a meteorite strike."
Professor John Parnell, head of Geology & Petroleum Geology at the University of Aberdeen, chipped in with: "These rocks are superbly displayed on the west coast of Scotland, and visited by numerous student parties each year. We’re very lucky to have them available for study, as they can tell us much about how planetary surfaces, including Mars, become modified by large meteorite strikes. Building up the evidence has been painstaking, but has resulted in proof of the largest meteorite strike known in the British Isles."
Amor added: "If there had been human observers in Scotland 1.2 billion years ago they would have seen quite a show. The massive impact would have melted rocks and thrown up an enormous cloud of vapour that scattered material over a large part of the region around Ullapool. The crater was rapidly buried by sandstone which helped to preserve the evidence."
The researchers hope that the evidence they've gathered will help them to "understand the ancient impacts that shaped the surface of other planets, such as Mars", Amor concluded. ®