It may also be that terrestrial impactors represent more than just so-called
proto-planetary accretional material. Certainly there's a body of evidence
(both strong and weak) that a variety lunar meteorites have found their way
to Earth--material ranging from basalt to glass in composition. So this
reminds me that Earth can be occasionally bombarded by material (impact or
volcanic in origin?) from our nearest planetary neighbor--the Moon--which
has a very low escape velocity!
Louis Varricchio
Environmental Information Specialist/Research Associate
Upper Midwest Aerospace Consortium
University of North Dakota
Grand Forks, N.D. 58202-9007 U.S.A.
Telephone: 701-777-2482
E-mail (in N.D.): varricch@umac.org
E-mail (in Vt.): morbius@together.net
>>> "E.P. Grondine" <epgrondine@yahoo.com> 06/15 1:13 PM >>>
Hello Phil and all -
--- Phil Bagnall <phil@ticetboo.demon.co.uk> wrote:
>snip<
> My gut feeling, for what it is worth, is that while
> the K/T event was
> probably due to a giant impactor, the other mass
> extinctions probably were
> not.
My interest lies with smaller historical impactors, so
I can't reel this data off the top of my head, but I
think that if you check with the Cambridge Conference
Archives maintained by Bob Kobres on his web site,
you'll find that every mass extinction has now been
linked with contemporaneous impact crater(s).
more...
> The lack of recent extinction episodes is
> consistent with an evolving
> Earth in which geo-catastrophic events decline with
> time as the Earth
> settles into a state of equilibrium.
It may also be that most of the "debris" left over in
our solar system has finally acreted, but I wouldn't
bet my life on it, or any one else's for that matter.
EP
>
> Phil Bagnall
> www.ticetboo.demon.co.uk
>
>
>
>
>
> ----------
> Archives located at:
> http://www.meteoritecentral.com/list_best.html
>
> For help, FAQ's and sub. info. visit:
> http://www.meteoritecentral.com/mailing_list.html
> ----------
>
>
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com
----------
Archives located at:
http://www.meteoritecentral.com/list_best.html
For help, FAQ's and sub. info. visit:
http://www.meteoritecentral.com/mailing_list.html
----------
----------
Archives located at:
http://www.meteoritecentral.com/list_best.html
For help, FAQ's and sub. info. visit:
http://www.meteoritecentral.com/mailing_list.html
----------