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L'Aigle and LL7

Bonjour Marc, Luc & Jim Labenne,
Hello List,

Congrats on your dream come true!
How beautiful it is, this meteorite which fell at L’Aigle in 1803. I’m
pretty sure everybody would like to possess it, me too, of course. But
the small specimens you mention will probably be very expensive.

Açfer 214 (along with Açfer 182 and Açfer 207) is not only metal-rich
but also volatile-poor which makes it unique in several respects.

With regard to Sahara 97037 (recently reclassified LL7) there is not
much information available at the moment.

Here’s what I found in my documents and my personal database. Presently
there are four Antarctic meteorites classified LL7 and two non-Antarctic
LL7 finds (your Sahara 97037 and Crockers Well).

.................... snip ...................

1) AMN 17-1, 1994:

EET 92012   1.1 x 0.9 x 0.8cm    2   gr   Fa30/Fs24
EET 92013   2.0 x 1.5 x 1.4cm    9.9 gr   Fa30/Fs24
EET 92016   2.1 x 1.5 x 1.5cm   10.1 gr   Fa30/Fs24

Macroscopic description: C. Satterwhite

The exterior surfaces of these specimens are greenish-gray in color.
Sulfide grains are visible on the exterior. The medium-grained, interior
matrices are light to medium gray with numerous light and dark colored
mineral grains scattered throughout.

Thin section (EET 92012,2; 92013,2; 92016,2) Description: B. Mason

These sections are so similar that a single description suffices; the
meteorites are certainly paired. They show an aggregate of small
anhedral olivine and pyroxene grains (grain size 0.05-0.1 mm), with a
few coarser aggregates which appear to be vestigial chondrules. Minor
amounts of nickel-iron and troilite are present. Microprobe analyses
show olivine and pyroxene of uniform composition: olivine, Fa30;
orthopyroxene, Wo2 Fs24. One grain of diopside, Wo40 Fs9, was analyzed.
A little plagioclase, An10, is present.

2) Yamato 74160 (LL7)

TAKEDA H. et al. (1984) On the chondrite-achondrite transition:
Mineralogy and chemistry of Yamato 74160 - LL7 (Earth Plan. Sci. Lett.
71, 329-339).

3) Crockers Well (LL7 breccia) is a small 3.8 g stone found by J.E.
Johnson in 1956 on a granite hill half a kilometer north of East Crocker
uranium prospect, Plumbago Station, South Australia (32°  01' S, 139°
47' E). It is a small button-shaped stone (1.8 x 1.5 x 1.2 cm) with a
fusion coating on one side. It is moderately iron stained.
In thin-section, Crockers Well has a brecciated texture with no visible
chondrules. Clasts are angular, up to 7 mm across, and sit in a fine
grained crystalline matrix. Clasts are recrystallized assemblages of
olivine, pyroxene and plagioclase. Nickel-iron and troilite are present
in minor amounts. Olivine shows a narrow range in composition from
Fa29.6 to Fa30.1 (9 analyses), orthopyroxene (Fs23.7 to Fs24.2) is very
calcium rich (Wo2.7 to Wo4.0 (13 analyses), and the clinopyroxene
compositions range from Fs9.9 to Fs13.4, Wo38.3 to Wo43.6 (6 analyses).
Plagioclase shows the widest range in composition, Ab74.4-87.4
An9.1-24.1 Or1.5-3.9 (9 analyses).  Crockers Well is classified as an
LL7 breccia on the basis of silicate compositions which fall within the
LL range, the high calcium content of orthopyroxene (> 1.0 wt.% as
suggested by Dodd et al., 1975) and the brecciated texture of the sample
(Meteoritics 26-3, 1991, 250).

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Best meteoritical wishes,

Bernd (Pauli)