[meteorite-list] Fwd: Ad: North American meteorite - San Bernardino Wash (L5)

From: Jason Utas <meteoritekid_at_meteoritecentral.com>
Date: Wed, 22 Jan 2014 23:51:17 -0800
Message-ID: <CABEOBjLjTJB0zYLZEhm7i7=pzYGRxSw+mYmoUn7om463ba3mCQ_at_mail.gmail.com>

Helo Bob, All,

>I agree, they definitely look different.

'Nuff said. You could assume "microclimates," but I wouldn't start
putting forth a hypothesis like that without something substantial
like argon data to tie the two stones together. The Meteoritical
Bulletin is clear on pairing:

http://meteoriticalsociety.org/?page_id=59

a) Level of scrutiny. Sequential names comprising a prefix and numeric
suffix will be given to new meteorites without checking for possible
pairings, although a single (collective) name may be given in cases
where fragments fit together or similar-looking fragments are found
within a few meters of each other.

b) Pairing groups. Two or more newly discovered meteorites in dense
collection areas may be considered paired with each other or with
another formally named meteorite if there is overwhelming evidence,
including geographic data, that is consistent with the meteorites
being part of a single fall. The evidence must be evaluated by the
Committee. All approved members of a pairing group will be named with
a geographic prefix plus a number in the same way as are unpaired
meteorites; special type-specimen requirements will apply to newly
paired meteorites (section 7.1f). If two or more numbered meteorites
with formal names are subsequently determined to be paired, their
names should not be changed. Pairing groups may be referred to
collectively by the lowest specimen number, the most widely studied
mass number or the largest mass number (e.g., the EET 87711 pairing
group).

To emphasize the important part, "a single (collective) name may be
given in cases where fragments fit together or similar-looking
fragments are found within a few meters of each other."

They look different and weren't found within meters; the necessary
evidence clearly isn't there. Anything else is guesswork.

Regards,
Jason


On Mon, Jan 20, 2014 at 4:06 PM, Robert Verish <bolidechaser at yahoo.com> wrote:
>
>
> Yes Jason,
> I agree, they definitely look different.
> But what has me puzzled is something that is not all that apparent in our images. The exterior of our two stones.
> Your stone has a very well-preserved exterior (even though your interior is a uniformly-colored W3), whereas,
> my exterior (which is not visible in the image) is gone, actually eroded. Yet somehow, my stone's interior
> is less weathered than your stone (my stone was classified as "W1").
> I wonder, if the interior of my stone were to weather to a "W3", just how much it would look like your stone?
>
>
> But, to directly answer your question, I would have to refer you to my latest Meteorite-Times article:
> http://meteorite-recovery.tripod.com/2014/jan14.htm
> for my description of how a cluster of obviously-paired fragments found at SBW had such a variation in "looks",
> that it prompted me to sample a number of them and to actually have two of those fragments classified.
> For your convenience, I'll show them here:
>
> Pinto Mountains -- (L6 S3 W1 Fa23.8+/-0.3% n=16; low-Ca pyroxene Fs20.3Wo1.5 n=17)-- 1955 stone
> San Bernardino Wash -- (L5 S2 W3 Fa24.6+/-0.6% (n=7) -- (UCLA type-specimen) -- 2010 stone
> San Bernardino Wash -- (L5 S1 W3 Fa24.0+/-0.2% (n=24) -- 2012A fragment
> San Bernardino Wash -- (L5 S2 W1 Fa23.8+/-0.4% (n=14) -- 2012B fragment
>
>
> This just might be a case of (very) micro-environments acting immediate to where each fragment is found, that is causing all of these differences.
>
> I'm open to any and all other explanations,
> Bob V.
>
>
>
>
>
> On Monday, January 20, 2014 2:48 PM, Jason Utas <meteoritekid at gmail.com> wrote:
>
> Hello Bob, All,
>>Just home from a hunt, haven't had the opportunity to reply until now.
>>I don't have photos of the other stone/fragments, but I do have a few
>>photos of SBW#1 on hand:
>>
>>http://meteoritegallery.com/wp-content/uploads/2014/01/DSCN7095.jpg
>>
>>http://meteoritegallery.com/wp-content/uploads/2014/01/DSCN7101.jpg
>>
>>http://meteoritegallery.com/wp-content/uploads/2014/01/comparison.jpg
>>
>>Is there any evidence for pairing beyond "equilibrated L?" As you can
>>see, that slice looks a bit different.
>>Regards,
>>Jason
>>
>>www.fallsandfinds.com
>>
>>
>>
>>On Mon, Jan 20, 2014 at 1:44 PM, Robert Verish <bolidechaser at yahoo.com> wrote:
>>> For those collectors with an interest in North American meteorites,
>>> I would like to bring your attention to an eBay offering (ending soon) of a classified find from the California Mojave Desert:
>>> San Bernardino Wash (L5)
>>> http://www.ebay.com/itm/221353605398
>>>
>>>
>>> This under-appreciated meteorite promises to become better-known now that
>>> additional field-work and research results are starting to appear on the Internet:
>>>
>>> https://www.google.com/#q=San+Bernardino+Wash+L5+meteorite+strewn-field
>>>
>>> Although the study of this area is too early to determine the possible TKW of this meteorite,
>>> it certainly will not rival Gold Basin (L4/6), but it promises to be the next "Trilby Wash".
>>> The specimens that I am offering are the remaining slices from the samples used to determine pairing.
>>> These two classifications confirmed their pairing to the SBW(L5) type-specimen held at UCLA.
>>> I will only be offering additional specimens for auction until the cost of this lab-work has been defrayed.
>>> But, as usual, I will continue to accept requests for samples by any interested researchers.
>>>
>>> Thank you for your interest,
>>> Bob V.
>>> ______________________________________________
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>>
>>
Received on Thu 23 Jan 2014 02:51:17 AM PST