[meteorite-list] Rocks from Space Picture of the Day - February 24, 2010

From: Darryl Pitt <darryl_at_meteoritecentral.com>
Date: Wed, 24 Feb 2010 13:12:52 -0500
Message-ID: <38128441-C5D4-48AE-A85E-9A15458C2CE2_at_dof3.com>

Dear List and Mike, Adam, Carl...

The voids remarked upon are not vesicles but an artifact of
weathering. The depressions seen are the end points where by water
penetrated the meteorite and you just aren't able to see the entry
point (which were the crevasses between the ziggurat structures).

For vug lovers--and I count myself among you!: Lovina does indeed
contain a blanketing of tiny vugs, which are fun to have but are
actuality only fully oxidized iron sulfide pockets. Remember, Lovina
was in saltwater for centuries, if not longer. If you enlarge and
scan the image of the cut surface, you can see where the sulfide
remains in the matrix and where it oxidized out.

As expressed by J. Wasson, the compositional fingerprint (the
meteorite's DNA, if you will) is the incontrovertible smoking gun.


All best / Darryl






On Feb 24, 2010, at 12:09 PM, Adam Hupe wrote:

> Very interesting, what are voids (vesicles) doing in an iron
> meteorite? I have only heard of sparse vugs found in one iron
> before and thought vesicles would most certainly disqualify an
> object from being an iron meteorite. Has cosmic ray exposure
> testing been done? It would be interesting to see how long this
> object has been in space.
>
> Best Regards,
>
> Adam


On Feb 24, 2010, at 12:21 PM, Galactic Stone & Ironworks wrote:

> HI Adam and List,
>
> This is a fascinating specimen. Surely it represents a
> previously-unknown parent body.
>
> While the presence of vugs/vesicles suggests the specimen was not
> formed in a vacuum, maybe there was some gases present during the
> formation.
>
> For example, suppose a large comet slammed into a predominately-iron
> asteroid. Comets contain large volumes of material that can
> sublimate, and maybe during the collision, some of this gaseous
> material injected into the iron body. The heat and/or shock resulting
> from the collision provided inroads for the cometary material by
> expanding existing fissures or faults. Then the intermingled material
> rapidly cooled, forming the vesicles we see now. The massive shock
> and/or heating would also wipe out the native widmanstatten pattern
> present in the iron body, leaving behind an ataxite-like mass without
> the typical crystallization patterns......???
>
> Then this curious mass fell to Earth and experienced
> weathering/alteration to provide the strange external appearance we
> see now.
>
> Or, to play devil's advocate, perhaps this is a very atypical type of
> industrial slag unlike any seen before. Is there any industry
> present in the area where this mass was found?
>
> Best regards,
>
> MikeG
>
>
Received on Wed 24 Feb 2010 01:12:52 PM PST