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Re: Ichthyosaurus fossilised in mid-birth ??




On Sat, 23 Jul 2005 08:47:51 +0100 (BST) Aidan Karley
<aidan_karley@yahoo.co.uk> writes:
> 
> --- Phil Bigelow <bigelowp@juno.com> wrote:

> > The burial has been interpreted to be the result of a sudden 
> massive
> > dune
> > collapse.
> > The Ankie baby clutch is also thought to have been buried by a 
> dune
> > collapse. 


>     Something would have been necessary to change the structural
> strength of the dune to get a collapse flow of some metres of
> thickness. The normal lee scarp flows on aeolian dunes are what? - a
> few mm thick? I'm trying to work up a scenario to generate such a
> strength change.


Ever since the dune-collapse idea first arose, I have thought that its
hypothesized sediment mechanics characteristics would make a good masters
thesis.

Lee scarp stability depends on grain size, grain shape, grain wetting,
geometry of the grain packing (random, imbricated, face-centered,
body-centered, close packed, tight packed, etc.), overburden (if any),
angle of repose, and who knows what else.

This would be a good old-fashioned sediment engineering study, the way
your grandpa used to do it***.  It could be a major contribution, all
done by an enterprising student.

***Walking 16 miles to school in the snow every morning, with no shoes,
and with only a slide rule and a stale crust of bread for companionship
at night.

<pb>
--