- Ullapool bolide impact
Evidence for a bolide impact centered on Ullapool was published by a combined team of scientists from the
University of Oxford and theUniversity of Aberdeen , in March 2008. [ [http://www.abdn.ac.uk/mediareleases/release.php?id=1275 University of Aberdeen media release, 26 March 2008] ; [http://www.ox.ac.uk/media/news_releases_for_journalists/080326.html Oxford University media release, 26 March 2008] .] The evidence is centred onUllapool , a harbour town onLoch Broom in theRoss and Cromarty district of the Highland council area of northwestScotland . This suggests it was the largestbolide impact ever to strike what are now theBritish Isles . The impact, about 1.2billion years ago , melted rock at the site and left parallel shock fractures in quartz andbiotite and a tell-tale trace ofiridium . Centered on theimpact crater , a wide ejecta field has been traced, some 50 km across. The affected layer of rock, which on land stretches fromGairloch in the south toStoer in the north is six to 22 metres thick.Urquhart, Frank, (27 March 2008 ) "Discovery with deep impact on Scots coast". Edinburgh. "The Scotsman".] Until recently, these anomalous formations [The strata under study are part of the Stac Fada Member of the Precambrian Stoer Group of Scotland.] were unsatisfactorily credited to an isolated instance ofvolcanism .The crater, preserved under sedimentary layers of
sandstone , is currently presumed to lie under theMinch , the waterway that separates theIsle of Lewis in theOuter Hebrides from the north-west Highlands of Scotland. It has been estimated that the impact would have created a blast with the force of 145,000 megatons and that the shock wave would have created winds of 420 kmh as far away as the site of modernAberdeen .ee also
*
Silverpit crater , the only other proposed impact crater in or near the British Isles.
*Impact event
*List of impact craters on Earth
*North West Highlands Geopark
*Geology of Scotland References
*Kenneth Amor, Stephen P. Hesselbo, Don Porcelli, Scott Thackrey, and John Parnell, [http://www.gsajournals.org/perlserv/?request=get-document&doi=10.1130%2FG24454A.1 "A Precambrian proximal ejecta blanket from Scotland"] , "Geology" March 2008:pp. 303–306.
Notes
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