[meteorite-list] Sutter's Mill BSE - two more

From: Carl Agee <agee_at_meteoritecentral.com>
Date: Fri, 25 May 2012 22:15:16 -0600
Message-ID: <CADYrzhroRVZ2MU6kvAqFhPNy4HDvWgBm1S8YGM1zkhOh6SxVVQ_at_mail.gmail.com>

Hi Richard,

I haven't seen a thin section of Sutter's Mill yet, but my guess is
that it will be very dark, just like the meteorite, so maybe not that
illuminating. I prefer backscatter electron images because they not
only show texture, but also image chemical compositional variations.
Like the dark olivines in my images?- they are Mg2SiO4-rich, the
light shaded olivines are Fe2SiO4-rich. Bright patches indicate high
iron or Ti or Cr, and so on.

As to the CaO, the electron microprobe does not do carbon very well so
it usually comes up with low totals on carbonates. I looked at the
data today and we found 4 separate crystals with this composition in
one of the small SM sections -- after perusing the CM literature
today, I am pretty sure this is calcite or aragonite -- thought by
some to form during aqueous alteration and commonly found in CMs.

With respect to the classification and type, I will leave that to the
unequilibrated chondrite experts like Jeff Grossman and Alan Rubin.

MetSoc will be very interesting this year: Tissint, Sutter's Mill, and
NWA 7034. You haven't heard about NWA 7034? Oh you will...

Carl Agee


On Fri, May 25, 2012 at 7:04 PM, Richard Montgomery
<rickmont at earthlink.net> wrote:
> Carl and List,
>
> I'm struck by the chondrule variation...can't wait to see a TS (hi
> Anne!)....so it's time to ask about the rabbit hole:
>
> As I mentioned I'm just guessing here....not a CM2, due to chondrules
> actually so present, right? Not a CM3 either (if there ever is such a thing)
> due to the rim alterations and aqueous stuff; dark matrix like a CM, yet
> more crowded chondrules; complete CaO crystals; lacking so far of seeing any
> CAIs....what's your guess at this point??
>
> Next Halloween I can dress up as a petrologist scientist....but won't fool
> anyone. ?Fun to speculate, though.
>
> Richard M
>
>
> ----- Original Message ----- From: "Carl Agee" <agee at unm.edu>
> To: "meteoritelist meteoritelist" <meteorite-list at meteoritecentral.com>;
> "Jeff Grossman" <jngrossman at gmail.com>
> Sent: Friday, May 25, 2012 2:03 PM
> Subject: Re: [meteorite-list] Sutter's Mill BSE - two more
>
>
>> Jeff,
>>
>> You mean the area in the SW quadrant? It's permeated with the bright
>> material? It could be sulfide, but I didn't get a chance to EDS or
>> probe it yesterday. It's all somewhat bewildering, there is so much
>> look at, so I am starting with the simple stuff that give good
>> microprobe totals -- haha!. Beware of this meteorite! Like going down
>> the rabbit hole....
>>
>> Carl
>>
>>
>> -----------------------------------------
>> Carl,
>>
>> What's the difference between the two lithologies visible in the first
>> of these two photos?
>>
>> Jeff
>>
>> On 5/25/2012 2:19 PM, Carl Agee wrote:
>>
>>>
>>> http://www.facebook.com/photo.php?fbid=4042491099560&set=a.1076549432872.2012978.1200325441&type=1&ref=nf
>>
>>
>>>
>>> http://www.facebook.com/photo.php?fbid=4042494859654&set=a.1076549432872.2012978.1200325441&type=1&ref=nf
>>
>>
>>>
>>
>>
>> --
>> 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/
>> ______________________________________________
>>
>> Visit the Archives at
>> http://www.meteoritecentral.com/mailing-list-archives.html
>> Meteorite-list mailing list
>> Meteorite-list at meteoritecentral.com
>> http://six.pairlist.net/mailman/listinfo/meteorite-list
>>
>

-- 
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/

Received on Sat 26 May 2012 12:15:16 AM PDT