[meteorite-list] Sterling, help with some calcs please

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Thu, 21 May 2009 13:26:18 -0700 (PDT)
Message-ID: <954929.20591.qm_at_web36901.mail.mud.yahoo.com>

Hi Sterling -

Do you think that we'll ever see Smit's refutation of Keller get any media play? Sadly, my guess is "no".

I wonder if Baptistina family itself was not formed when a comet hit an asteroid.

Thanks for the updaate. With that information I suppose you and Elton will be along with a statement of the effects shortly: Infra-red; blast overpressures, molten rock rain and its dispersal, aerosol sulfur and CO2.
 
Thanks,
Ed


--- On Wed, 5/20/09, Sterling K. Webb <sterling_k_webb at sbcglobal.net> wrote:

> From: Sterling K. Webb <sterling_k_webb at sbcglobal.net>
> Subject: Re: [meteorite-list] Sterling, help with some calcs please
> To: "Mr EMan" <mstreman53 at yahoo.com>, meteorite-list at meteoritecentral.com, "E.P. Grondine" <epgrondine at yahoo.com>
> Date: Wednesday, May 20, 2009, 6:45 PM
> EMan, EP, List,
>
> The sea-floor-dredged fragment is of a carbonaceous
> chondrite. It's a "fossilized" meteorite, meaning it's
> seriously been altered by the terrestrial environment,
> with replaced minerals and all the rest. It was found
> some years ago. I've seen a photo of it, but can't find
> that website today, but it is an encapsulated clast that
> can only be identified as carbonaceous by the simple
> fact that it's so rich in carbon.
>
> The discovery article is:
> "A meteorite from the Cretaceous/Tertiary boundary"
> by Frank T. Kyte The Abstract is at:
> http://www.nature.com/nature/journal/v396/n6708/abs/396237a0.html
> "Cretaceous/Tertiary boundary sediments
> are now
> widely recognized to contain the record of a large
> asteroid
> or comet impact event, probably at the site of the
> Chicxulub
> crater on the Yucatan peninsula. After nearly two decades
> of intensive research, however, much remains unknown
> about the specific nature of the projectile and of the
> impact
> event itself. Here we describe a 2.5-mm fossil meteorite
> found in sediments retrieved from the Cretaceous/Tertiary
> boundary in the North Pacific Ocean that we infer may be
> a piece of the projectile responsible for the Chicxulub
> crater.
> Geochemical and petrographic analyses of this meteorite
> indicate that it probably came from a typical metal- and
> sulphide-rich carbonaceous chondrite rather than the
> porous aggregate type of interplanetary dust considered
> typical of cometary materials. The fact that meteorite
> survival
> should be enhanced by impacts at low (asteroidal)
> velocities
> also implies that this meteorite had an asteroidal rather
> than a cometary origin."
>
> The impact angle at Chicxulub appears to have been low,
> 20 to 30 degrees above the horizontal. Nice animation at
> the bottom of this webpage:
> http://www.psi.edu/~betty/chicx3d.html
>
> Then, by a happy coincidence, a year or so ago, an orbital
> regression program revealed that the big impactor was
> likely
> a large chunk of the breakup fragments of the parent body
> of the Baptistina asteroid family:
> http://en.wikipedia.org/wiki/Chicxulub_crater#Astronomical_origin_of_asteroid
>
> The original paper by Bottke can be found here as a pdf:
> http://www.boulder.swri.edu/~bottke/Reprints/Bottke_2007_Nature_449_48_Baptistina_KT.pdf
>
> I call it a happy coincidence because the Baptistina
> Family
> are... you guessed it -- carbonaceous chondrites, like the
> biggest surviving member, which is 298 Baptistina. The
> original or parent body was about 170 kilometers across.
> Another fragment of the Baptistina Family is believed to
> have made the crater Tycho on the Moon 108 million years
> ago. Those guys really got around...
>
> There's a paper that calculates that there should be lots
> of
> Earthite chunks from the Chicxulub impact littering the
> Moon and Mars. They call them Chicxulubites!
> http://www.igeofcu.unam.mx/divulgacion/geofinternacional/iframes/anteriores/2008/03/poveda.pdf
> Add that term to your list of meteorite types... and watch
> for them on eBay.
>
> As for the latest Keller piece, I don't bother to read
> Keller any
> more. Here's her own university's press release summarizing
> it:
> http://www.dailyprincetonian.com/2009/05/06/23652/
> Her papers are dense and jargonistic, hard for someone
> who's
> not an academic geologist to plow through, but even I
> found
> the "hole" in her original block-buster paper, "proving" a
> missing 300,000 years between impact and K-T boundary.
> That hole is that 275,000 years of the missing 300,000
> years
> is missing from her evidence, with no evidence that it's
> missing. In other words, there really is no gap, or at
> most
> a possible 25,000 year gap, hard to measure accurately.
> That's as good as "right away" for me.
>
> Then I discovered her biggest opponent -- Smit. He's a
> Dutch/
> American sedimentologist. He basically takes her so-called
> evidence apart piece-by-piece (and he demonstrates that it
> is largely incompentent, although he does not say it in
> those
> words... exactly.) You want to find out what's wrong with
> Keller's work? Read this:
> http://www.falw.vu/~smit/csdp/debates.htm
>
> Keller's now blaming the Deccan Traps, big flood basalts
> in
> India. Flood basalts coordinate perfectly with big
> impacts;
> the biggest two instances are at the K-T extinction and at
> the Permian extinction (the Siberian Traps) Coincidence?
> (That, or leprachans...) And it's easy to demonstrate the
> mechanism by which impacts CAUSE flood basalts!
> http://www.newgeology.us/presentation35.html
> And we have an existing perfect example on Mercury, with
> antipodean lava flooding opposite a big impact, so even if
> Keller's right... She's wrong.
>
> If you Google "keller chicxulub" at Google News, you will
> get scads of stuff on the latest silliness.
>
>
> Sterling K. Webb
> --------------------------------------------------------------------------------
> ----- Original Message ----- From: "Mr EMan" <mstreman53 at yahoo.com>
> To: <meteorite-list at meteoritecentral.com>;
> "E.P. Grondine" <epgrondine at yahoo.com>
> Sent: Wednesday, May 20, 2009 3:01 PM
> Subject: Re: [meteorite-list] Sterling, help with some
> calcs please
>
>
> >
> >> From Mr Buttinsky Eman: I am a wee skeptical
> regarding meteorite fragments from ancient impacts in
> general and Chixculub specifically. There is also an H4
> fragment recovered in sea floor dredging which was announced
> as the smoking gun. Unfortunately I continue to get
> group postings reliably so again I am out on a limb so I
> haven't read Keller's latest. But I am looking elsewhere for
> this report.
> >
> > Elton
> >
> > --- On Wed, 5/13/09, E.P. Grondine <epgrondine at yahoo.com>
> wrote:
> >>
> >> Hi Sterling, all -
> >>
> >> Given Keller's latest KT announcements, could you
> give us
> >> some rough numbers on infra-red, blast
> overpressures, winds,
> >> and molten rock vapor from the KT impact? Given
> the
> >> kt-fossil meteorite, it seems safe to me to infer
> a comet
> >> impactor.
> >>
> >> E.P. Grondine
> >> Man and Impact in the Americas
> > ______________________________________________
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>
>
>


      
Received on Thu 21 May 2009 04:26:18 PM PDT