[meteorite-list] Official Announcement NWA 6077 is Paired with NWA 5400

From: Greg Catterton <star_wars_collector_at_meteoritecentral.com>
Date: Tue, 5 Oct 2010 09:01:35 -0700 (PDT)
Message-ID: <374751.70325.qm_at_web46403.mail.sp1.yahoo.com>

Its great that there is such a nice amount of this material when considering all the pairings... With over 10kg of this material in pairings known so far, I am willing to bet there is likely a good amount more still.
I bet the Brachinties are coming out of the woodwork to be tested.

Greg Catterton
www.wanderingstarmeteorites.com
IMCA member 4682
On Ebay: http://stores.shop.ebay.com/wanderingstarmeteorites
On Facebook: http://www.facebook.com/WanderingStarMeteorites


--- On Tue, 10/5/10, John higgins <geohiggins at yahoo.com> wrote:

> From: John higgins <geohiggins at yahoo.com>
> Subject: [meteorite-list] Official Announcement NWA 6077 is Paired with NWA 5400
> To: meteorite-list at meteoritecentral.com
> Date: Tuesday, October 5, 2010, 9:26 AM
> Official Announcement
> ?
> NWA 6077 IS PAIRED WITH NWA 5400
> ?
> North West Africa 6077?Description:
> An olivine-rich assemblage with cumulate (or possibly
> metamorphic) texture
> exhibiting triple junction grain boundaries. Olivine
> (Fa30.2-30.7),
> orthopyroxene (Fs24.1-24.5Wo2.1-2.0), clinopyroxene
> (Fs9.4-10.0Wo44.0-43.5),
> altered kamacite, chromite, chlorapatite, Ni-bearing
> troilite and/or pyrrhotite.
> No plagioclase was found. Analysis conducted at the
> Carnegie Institution of
> Washington show that the oxygen isotopic composition of
> this specimen plots on
> the Terrestrial Fractionation Line. In conjunction with the
> mineral compositions
> and texture, this establishes that NWA 6077 is paired with
> NWA 5400.
> ?
> The averages of the two Oxygen Isotope Results are:
> d17O = 2.780, d18O = 5.358, D17O = -0.019 (all in per mil)
> ?
> This brachinite was recovered out of Morocco in 2008?as
> one whole stone and
> purchased by John Higgins. It was submitted for
> classification to Dr. Tony
> Irving and was given the provisional classification number
> of NWA 6077. This
> meteorite has a modest TKW of less than 1000g after the
> type specimen was
> removed.
> ?
> Personal?Notes: Although I suspected that the two were
> possibly?paired due to
> similarities in?visual observations?and classification
> compositions, I felt it
> was important to wait for secondary Oxygen Isotope results
> to come in which have
> recently confirmed the results beyond a reasonable doubt.
> There was also another
> important factor besides Oxygen Isotope testing that?had
> to be taken into
> account. Orthopyroxene which is present in NWA 5400?was
> missed the first time
> around in NWA 6077?because it looks identical to
> clinopyroxene in back-scattered
> electron images.?However?further in-depth
> microprobe?studies of the thin section
> have confirmed?the presence of?orthopyroxene, and?are
> now noted in the updated
> description. I feel that making a self pairing based upon
> my own
> visual?observations, is not only unethical, inappropriate,
> and akin to pirating,
> but would only feed the controversies regarding this
> meteorite without the
> scientific testing data to back up such speculation, such
> action would be
> premature, immoral?and unfair to Greg Hupe and NWA 5400
> after all the time and
> effort he put into the study of what has become one of the
> most important
> meteorite finds in history.
> ?
> Have a Great Day!
> John Higgins
> IMCA#9822
>
>
> ? ? ?
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Received on Tue 05 Oct 2010 12:01:35 PM PDT