[meteorite-list] More on Chiang Khan

From: Martin Altmann <altmann_at_meteoritecentral.com>
Date: Sat, 22 Mar 2008 14:28:18 +0100
Message-ID: <000401c88c20$97dc04c0$177f2a59_at_name86d88d87e2>

And a little addendum: If cut, several Chiang Khans show a brecciation like
Juancheng.

Here an oriented example in possession of Oliver Alge, who a while ago
investigated the fall and recovered several stones more.
http://www.meteorite-oliver.com/f23-1.jpg

Unfortunately Chiang Khan became a victim of the recent hammer-hysterogeny
and got very expensive nowadays.

Happy Easter
Martin


-----Urspr?ngliche Nachricht-----
Von: meteorite-list-bounces at meteoritecentral.com
[mailto:meteorite-list-bounces at meteoritecentral.com] Im Auftrag von
bernd.pauli at paulinet.de
Gesendet: Samstag, 22. M?rz 2008 14:03
An: Meteorite-list at meteoritecentral.com
Betreff: [meteorite-list] More on Chiang Khan

Yagi K. et al. (1987) Petrology and Magnetic Properties Of Chiang
Khan, Thailand, Meterorite (Meteoritics 22-4, 1987, pp. 536-537):

Chiang Khan meteorite fell on Nov. 17, 1981 at Chiang Khan, Loei, Thailand.
The meteorite consists of olivine, orthopyroxene, clinopyroxene, chromite,
FeNi
metal, plagioclase, glass, troilite, and phosphate in order of abundance.
Olivine always forms barred or porphyritic chondrules. Its composition is
very
homogeneous with an average of Fo80, which is very close to the average com-
position of olivine of equilibrated H chondrites (Van Schmus, 1969).
Orthopyro-
xene usually forms radiating chondrules as fibrous crystals, whereas
clinopyroxene
is much less, occurring as fibrous crystals in the devitrified glass or
minute crystals
in the rim of orthopyroxene. Both orthopyroxene and clinopyroxene have
compositions
similar to those of these pyroxenes of equilibrated H chondrites (Van
Schmus, 1969).
Ca-poor pyroxene is nearly always orthopyroxene and clinoenstatite is almost
absent.
Plagioclase is present as microcrystalline aggregates only in a groundmass
of chondrules.
Chondrules are present, showing their textures well, but their outlines are
often not clear.
Glass is more or less devitrified, resulting in aggregates of fibrous or
microcrystals.
The composition of these aggregates is similar to that of Ca-rich pyroxene +
albitic
plagioclase.
When compositions of chromite are plotted in a diagram Mg/(Mg +Fe) vs. Al/
(Al + Cr),
all of them fall in the field of H chondrites (Bunch et al., 1967). From
these features the
meteorite is classified as an equilibrated chondrite of H5 type (Van Schmus
and Wood, 1967).
Water content and magnetic properties were measured.

Bunch T.E., Keil K., and Snetsinger K.G. (1967) GCA 31, 1569-1582.
Van Schmus (1969) Earth Sci. Rev. 5, 145-184.
Van Schmus WR. and Wood J.A. (1967) GCA 31, 747-765.

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Received on Sat 22 Mar 2008 09:28:18 AM PDT