[meteorite-list] Re:Comet hit Britain in mid sixth, century, AD?

[Darren Garrison]

On Sat, 22 Jul 2006 12:54:04 +0200, you wrote:

>Large impact phenomena come with a suit of identifiable things. If there was 
>such an event in Britain as recent as AD 540, then where are the ejecta layers, 
>the dust layers, the spherule layers, the impact glasses, the shocked quartz, 
>the impact craters, the extinction events in flora and fauna? There is no reason 
>why these should have vanished from the geological record in this case.

I'm not defending the "comet hit Britian" theory, but there CAN be a (fairly)
widely deadly hit without leaving (much) evidence that would be visible hundreds
of years later.  Look at Tunguska.  For how many miles radius would it have
killed (either instantly or over days or weeks from internal trauma) if it had
been over a populated area?  The British Isles are pretty small-- I'm guessing
that a Tunguska would wipe out a large percentage of the population.