[meteorite-list] [AD]: NWA 8276 - the "NOT SO" ordinary chondrite L3.00/W1 (and the start of an interesting discussion?)

From: Carl Agee <agee_at_meteoritecentral.com>
Date: Mon, 10 Mar 2014 19:38:57 -0600
Message-ID: <CADYrzhp++66NNabj-HHRD+U1VSvmrJ=5ZNamsNrm-HXpnjXJQA_at_mail.gmail.com>

Hi John,

NWA 8276 was analyzed completely independently of NWA 7731, although
we also did that one. Each one has its own data set.

Carl
*************************************
Carl B. Agee
Director and Curator, Institute of Meteoritics
Professor, Earth and Planetary Sciences
MSC03 2050
University of New Mexico
Albuquerque NM 87131-1126

Tel: (505) 750-7172
Fax: (505) 277-3577
Email: agee at unm.edu
http://meteorite.unm.edu/people/carl_agee/



On Mon, Mar 10, 2014 at 7:36 PM, kashuba <mary.kashuba at verizon.net> wrote:
> Carl,
>
>
>
> Is this based on the thin sections UNM made of possibly paired NWA 7731
> L3.00 W1?
>
>
>
> - John
>
>
>
>
>
> From: cb.agee at gmail.com [mailto:cb.agee at gmail.com] On Behalf Of Carl Agee
> Sent: Monday, March 10, 2014 6:23 PM
> To: Mendy Ouzillou
> Cc: kashuba; Adam Bates; Met-List
>
>
> Subject: Re: [meteorite-list] [AD]: NWA 8276 - the "NOT SO" ordinary
> chondrite L3.00/W1 (and the start of an interesting discussion?)
>
>
>
> Shock is low.
>
> On Mar 10, 2014 6:23 PM, "Mendy Ouzillou" <ouzillou at yahoo.com> wrote:
>
> Carl,
>
> Your comments and questions are always welcome and I am already looking into
> it ...
>
> Can you comment on the shock question below?
>
>
>
> Mendy Ouzillou
>
>
> ----- Original Message -----
>> From: Carl Agee <agee at unm.edu>
>> To: Mendy Ouzillou <ouzillou at yahoo.com>
>> Cc: kashuba <mary.kashuba at verizon.net>; Met-List
>> <meteorite-list at meteoritecentral.com>; Adam Bates <sales at bcmeteorites.com>
>> Sent: Monday, March 10, 2014 5:18 PM
>> Subject: Re: [meteorite-list] [AD]: NWA 8276 - the "NOT SO" ordinary
>> chondrite L3.00/W1 (and the start of an interesting discussion?)
>>
>> Probably none of my business, but I would have some thin sections
>> made. We did that for NWA 7731 for research and they are spectacular.
>> The porphyritic chondrules -- dazzling and crystal clear!
>>
>> Carl Agee
>> *************************************
>> Carl B. Agee
>> Director and Curator, Institute of Meteoritics
>> Professor, Earth and Planetary Sciences
>> MSC03 2050
>> University of New Mexico
>> Albuquerque NM 87131-1126
>>
>> Tel: (505) 750-7172
>> Fax: (505) 277-3577
>> Email: agee at unm.edu
>> http://meteorite.unm.edu/people/carl_agee/
>>
>>
>>
>> On Mon, Mar 10, 2014 at 6:13 PM, Mendy Ouzillou <ouzillou at yahoo.com>
>> wrote:
>>>
>>>
>>> John,
>>>
>>> That is a great question and one that deserves an educated response. I
>>> will
>> do my best, but hopefully Carl can chime in.
>>>
>>> We went back and forth on listing the shock for this stone and
>>> ultimately
>> felt it would be confusing. Shock equals heat and this stone being a 3.00
>> has
>> had no thermal metamorphism. It is possible that its shock value is as
>> high as
>> S2 but as I understand it there is no way to reliably measure shock in
>> such a
>> low petrologic state as 3.00.
>>>
>>> Best!
>>>
>>> Mendy Ouzillou
>>>
>>>
>>>
>>>> ________________________________
>>>> From: kashuba <mary.kashuba at verizon.net>
>>>> To: 'Mendy Ouzillou' <ouzillou at yahoo.com>;
>> 'Met-List' <meteorite-list at meteoritecentral.com>; 'Adam
>> Bates' <sales at bcmeteorites.com>
>>>> Sent: Monday, March 10, 2014 5:09 PM
>>>> Subject: RE: [meteorite-list] [AD]: NWA 8276 - the "NOT SO"
>> ordinary chondrite L3.00/W1 (and the start of an interesting
>> discussion?)
>>>>
>>>>
>>>> Mendy, Adam, List,
>>>>
>>>> Congratulations on discovering this special rock. I saw it in
>> Adam's room
>>>> in Tucson and we talked about it. A 3.00 calls to every collector. But
>>>> there was no shock rating so I was reluctant to buy. There was another
>>>> valuable stone at another dealer that I passed on for the same reason.
>>>>
>>>> Maybe I'm stuck in tradition, but when I'm considering a shocked
>> stone, I
>>>> like to know how shocked it is. When I'm considering a pristine
>> chondrite,
>>>> I want to know how pristine. That includes the effects of thermal
>>>> metamorphism, aqueous alteration, terrestrial weathering and shock.
>> None of
>>>> these is necessarily a deal breaker, but each plays into my seat of the
>>>> pants cost-benefit deliberation.
>>>>
>>>> Semarkona is considered unshocked and unequilibrated. It is spectacular
>> in
>>>> thin section. It's hard to know what NWA 8276 L3.00 W1 would look
>> like.
>>>>
>>>> Sincerely,
>>>>
>>>> John Kashuba
>>>> Bend, Oregon
>>>>
>>>> -----Original Message-----
>>>> From: meteorite-list-bounces at meteoritecentral.com
>>>> [mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Mendy
>>>> Ouzillou
>>>> Sent: Monday, March 10, 2014 12:35 PM
>>>> To: Met-List; Adam Bates
>>>> Subject: [meteorite-list] [AD]: NWA 8276 - the "NOT SO"
>> ordinary chondrite
>>>> L3.00/W1 (and the start of an interesting discussion?)
>>>>
>>>>
>>>>
>>>> Hello everyone, The NWA desert continues to thrill us this with unique
>> and
>>>> amazing specimens. NWA 8276 is just such a meteorite. It is the second
>> L3.00
>>>> and is "possibly" paired to NWA 7731. NWA 8276 features a
>> rich, black crust
>>>> and a yellowish matrix densely packed with chondrules. Extensive
>> analysis by
>>>> Dr. Carl Agee and Karen Ziegler support the 3.00 classification - a
>>>> classification that indicates no heat or aqueous alteration of any kind
>> (at
>>>> least as far as can be presently evaluated). In fact, this meteorite
>>>> represents material from the earliest history of our solar system. Older
>>>> than CAIs? Not sure, but maybe Dr. Agee can chime in.
>>>>
>>>> The complete writeup may be found here:
>>>>
>>>> http://www.lpi.usra.edu/meteor/metbull.php?sea=3.00&sfor=types&ants=&falls=&
>>>>
>>>> valids=&stype=contains&lrec=50&map=ge&browse=&country=All&srt=name&categ=All
>>>> &mblist=All&rect=&phot=&snew=0&pnt=Normal%20table&code=59487
>>>>
>>>>
>>>> The
>>>> explanation how this meteorite was identified makes for a short but very
>>>> good read (from MetBull):
>>>> "Adam Bates identified this meteorite from images he received as a
>> possible
>>>> pairing to NWA 7731,even though they came from a different Moroccan
>>>> meteorite dealer. Both pieces were then purchased within a few weeks of
>> each
>>>> other in October 2013."
>>>>
>>>> Adam Bates and I partnered on half the stone and anxiously awaited for
>> Dr.
>>>> Agee's results. It was not a given that this was in fact paired with
>> NWA
>>>> 7731, especially since the meteorite was bought from a completely
>> different
>>>> dealer. There were visual differences in the stone that led Carl to
>>>> initially believe that 8276 may be different from 7731. In the end, the
>>>> classification came back as L3.00 but with enough differences to state
>> that
>>>> NWA 8276 is "possibly" paired with NWA 7731. The terrestrial
>> weathering is
>>>> also
>>>> quite low and only an W1.
>>>>
>>>> Many people state meteorites as being rare, but some are certainly rarer
>>>> than others. The type 3.00 classification has only been given to 3
>>>> meteorites: Semarkona (LL3.00), NWA 7731 (L3.00) and now NWA 8276
>> (L3.00).
>>>> Here is an excerpt from Dr. Agee's FB discussion with David Weir on
>> the 3.00
>>>> classification and the rarity of this material:
>>>> "Grossman and Brearley (2005)define the subtypes less than 3.2 as
>> 3.15,
>>>> 3.10, 3.05, and 3.00. [This scale is] primarily based on the mean value
>> and
>>>> standard deviation of Cr2O3 in coarse ferroan chondrule olivines.
>> I'm not
>>>> saying that the Grossman and Brearley scheme is the ultimate, but it is
>>>> simply the standard currently. What will really improve the subtype 3
>>>> nomenclature (and understanding of unequilibrated OCs) are more samples
>> like
>>>> NWA 7731 and NWA 8276. Up to now we have so few in the 3.15-3.00 range
>> that
>>>> the statistics of small numbers makes it hard to have meaningful
>>>> subdivisions. I would gladly use an even finer scale (i.e. 3.01, 3.02,
>> 3.03,
>>>> 3.04 etc.) if it were actually established. The Grossman and Brearley
>> (2005)
>>>> scale is the only one that exists with any sort of sampling to anchor
>> it. We
>>>> just have too few samples to establish a finer scale. And when one
>> starts
>>>> talking about all the possible subtle differences around 3.00, I'm
>> not sure
>>>> if a
>>>> numerical, linear scale would even make sense. The nice thing about
>>>> discovering more of these very low type 3s is that more will hopefully
>> be
>>>> available for research. Semarkona, because much of it resides in India
>> and
>>>> some at the Smithsonian (I believe), it is hard to get a hold of. For
>>>> example we only have a couple thin sections of Semarkona at UNM -- not
>> even
>>>> a tiny fragment!"
>>>>
>>>>
>>>> The items for sale (and pricing) may be viewed at
>>>>
>>>> http://www.meteoritesusa.com/meteorites-for-sale-4/nwa-8276-l3-00-w1-a-remar
>>>> kable-and-scientifically-important-meteorite/
>>>>
>>>>
>>>> The photos have had no color manipulation and represent the true colors
>> of
>>>> this meteorite as viewed under studio lighting (5500K). Anyone
>> interested in
>>>> acquiring material may contact me by responding privately to this email
>> or
>>>> to Adam Bates (sales at bcmeteorites.com). The transaction and any
>> associated
>>>> details will be kept strictly confidential.
>>>>
>>>>
>>>> Regards,
>>>>
>>>> Mendy Ouzillou
>>>> ______________________________________________
>>>>
>>>> Visit the Archives at http://www.meteorite-list-archives.com
>>>> Meteorite-list mailing list
>>>> Meteorite-list at meteoritecentral.com
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>>
>>>>
>>>>
>>>>
>>>>
>>> ______________________________________________
>>>
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>>
Received on Mon 10 Mar 2014 09:38:57 PM PDT