[meteorite-list] vaca muerta eucrite

From: Mr EMan <mstreman53_at_meteoritecentral.com>
Date: Sat, 16 Aug 2008 21:46:20 -0700 (PDT)
Message-ID: <320412.47752.qm_at_web55204.mail.re4.yahoo.com>

--- On Thu, 8/14/08, mckinney trammell <bigpineartifacts at yahoo.com> wrote: vaca muerta eucrite--can anyone give any scientific info on this + pix?

Here are the basic points.

All known mesosiderites come from a common parent/daughter which was a Vesta-like differentiated asteroid(having eucrite and diogenite material and possibly iron core (e.g Crust-Mantle-Core) Since howardites are eucrite/diogenite/plus mixes some portion of regolith is likely incorporated in the overall petrology but too small for us to recognize as such.

This body was extensively disrupted by collision(s) which greatly mixed the strata: either a Vesta-like asteroid and it's a metallic core AND/OR some other massive iron body.

A massive portion (if not the entire body) was essentially turned into something akin to an Impact Melt Breccia(IMB) but with achondrite materials.

On petrological study of Vaca Mutera specifically, what is commonly referred to as "eucrite" nodules are a wide ranging mix of eucrite and diogenite composition. They do NOT represent a different fall or named meteorite.

Owing to differential weathering: iron weathering faster than silicate, the clasts of "eucrite" character have been recovered as nodules in the VM strewn field. They are also seen in sawed sections contained in classic meso "iron/silicate" masses. I don' have any statistcs or percentages but my swag is that they are probably less than 3-5% of this meteorite and would be rated as uncommon to rare. Perhaps others have better data.

I don't have a photo available but on a macro level the ones I have are fairly unremarkable; looking much like any other suspected meteorite: dark walnut-like without true fusion crust. I have been told that because of the random mix, their interiors contain a wide range of crystalline textures.

Regards,
Elton
Received on Sun 17 Aug 2008 12:46:20 AM PDT