[meteorite-list] Fwd: Peter's Stunning New Eucrite NWA 5230 paired with the Hupés' NWA 4883

From: Jason Utas <meteoritekid_at_meteoritecentral.com>
Date: Thu, 14 Aug 2008 16:14:27 -0700
Message-ID: <93aaac890808141614l6e0b3565gaf06725112e31f5c_at_mail.gmail.com>

Hola Mike, All,

>As for the logic, I've never heard anyone say that finding a carbonaceous clast in an L class meteorite means that the the two parent bodies are related. It just means that at some point a fragment of one parent body collided with another. If such clasts were common, then one might infer that the two bodies at some point in space and time were in relative proximity to each other.

Fair enough, but when one looks at the entire picture - especially
meteorites like Dhofar 007 which are structurally Eucritic, but
isotopically (oxygen isotopes) identical to Mesosiderites...the
evidence mounts. And one can't forget meteorites like Vaca Muerta,
which is full of Eucritic clasts (to a much higher degree than would
suggest mere impact-injected fragments)....well, a few small clasts is
one thing, but there's something bigger than sporadic collisions going
on.

>As far as the meso's and HED's having a common parent body, that is nearly impossible, especially if you believe that Vesta is the Parent Body of the HED's.

Asteroid 4 Vesta is a spectroscopic match for the HED's. That said, I
don't know if there are any other spectroscopic matches
around...anyone have a better idea?
Even so, 4 Vesta's link to HED's hasn't been proven beyond a doubt
yet, so your point is moot. The possibility exists that the parent
body for HED's has simply been completely destroyed, and that's very
possible...

>Consider that Vesta appears to be an intact body, with a core, mantle and crust. The HED's sample different depths of the crust. Where is there room for the Meso Parent Body? The MPB (Meso Parent Body) was completely destroyed by the collision that mixed the iron core with the basaltic crust. Vesta is intact, the MPB has been destroyed. Therefore they can't be the same Parent Body.

Hmmm....take a look at this article:

http://www.planetary.org/explore/topics/asteroids_and_comets/vesta.html

"At some point in its past, Vesta suffered a huge impact which left a
crater nearly as large as the asteroid itself (at 460 kilometers or
290 miles in diameter, it is 80 percent the width of Vesta). The
crater is so deep that it exposes materials from deep in Vesta's
mantle."

Deep mantle material could be potentially very rich in iron,
especially with such a gravitationally weak body (less gravity means
less consolidated core). Thus, I think it's rather safe to say that 4
Vesta *could* be the parent body for both types of meteorites...not to
say that it is, but it could be.

Jason



On Thu, Aug 14, 2008 at 1:51 PM, Michael Fowler <mqfowler at mac.com> wrote:
>
>
>
> Resent, don't think this went through the first time.
>
> Mike
>
>
>> http://www.marmet-meteorites.com/id41.html
>>
>> Peter writes:
>>
>> "It's NWA 5230, a maskelynite rich polymict eucrite breccia! Analized
>> by Tony Irwing, who writes: We made a discovery of a small mesodiderite
>> clast in it. This is an important observation that adds to the growing
>> evidence
>> for a common parent body for HEDDO and MESO meteorites! NWA 5230
>> is paired with NWA 4883. TKW is 909 g."
>
>
> I must disagree both with the above logic, and the rush to join the
> mesosiderite and HED parent bodies.
>
> As for the logic, I've never heard anyone say that finding a carbonaceous
> clast in an L class meteorite means that the the two parent bodies are
> related. It just means that at some point a fragment of one parent body
> collided with another. If such clasts were common, then one might infer
> that the two bodies at some point in space and time were in relative
> proximity to each other.
>
> As far as the meso's and HED's having a common parent body, that is nearly
> impossible, especially if you believe that Vesta is the Parent Body of the
> HED's. Consider that Vesta appears to be an intact body, with a core,
> mantle and crust. The HED's sample different depths of the crust. Where is
> there room for the Meso Parent Body? The MPB (Meso Parent Body) was
> completely destroyed by the collision that mixed the iron core with the
> basaltic crust.
>
> Vesta is intact, the MPB has been destroyed. Therefore they can't be the
> same Parent Body.
>
> Mike Fowler
> Chicago
>
>
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Received on Thu 14 Aug 2008 07:14:27 PM PDT