[meteorite-list] Black Inclusions in Howardites

From: Treiman, Allan <Treiman_at_meteoritecentral.com>
Date: Thu Apr 22 09:54:10 2004
Message-ID: <9CBE44BF7DE9D511960300500424D7D0112021_at_cassnt2>

Also, howardites commonly contain clasts of
carbonaceous chondrite material, nearly all
lik CM and CR chondrites.
  Zolensky ME, Weisberg MK, Buchanan PC, Mittlefehldt DW (1996)
Mineralogy of carbonaceous chondrite clasts in HED achondrites
and the moon. Meteorite. Planet. Sci. 31, 518-537.

  aht

Allan H. Treiman
Lunar and Planetary Institute
3600 Bay Area Boulevard
Houston TX 77058-1113
   281-486-2117
   281-486-2162 FAX
  treiman_at_lpi.usra.edu


-----Original Message-----
From: Bernd Pauli HD [mailto:bernd.pauli_at_lehrer1.rz.uni-karlsruhe.de]
Sent: Monday, February 25, 2002 1:31 PM
To: vincent jacques
Cc: meteorite-list_at_meteoritecentral.com
Subject: [meteorite-list] Black Inclusions in Howardites


vincent jacques wrote:

> I look for information and reports of analyses about
> the nature of black inclusions in howardite type.


Hello Vincent and List,

Several howardites (Bununu, Chaves, DaG 779, Hughes 005, Lohawat,
Malvern, Monticello, NWA 776, Old Homestead 001) are glass-rich.
They contain dark, glassy inclusions - not too surprising for
breccias because of their impact history.

Chaves contains both dark brown and also devitrified glasses, which
are intimately associated with crystalline grains of plagioclase and
pyroxene. Monticello is particularly glass-rich (15% dark brown glass
fragments).

The Varela article in MAPS provides very important background info,
figures, photos, and detailed analyses.

References:

VARELA M.E. et al. (1998) The ubiquitous presence of silica-rich glass
inclusions in mafic minerals: Examples from Earth, Mars, Moon and the
aubrite parent body (MAPS 33-5, 1998, 1041-1051).

MONTEIRO J.F. (1989) Preliminary study of the Chaves howardite
(Meteoritics 24-4, 1989, pp. 305-306).

SINGH U.K. et al. (1998) Lohawat howardite: Chemical and mineralogical
characteristics and cosmogenic records (Meteoritics 33-4, 1998, A146).

Olsen E.J. et al. (1986) Monticello: A glass-rich howardite (Meteoritics
22-1, 1987, 81-96).


Best wishes,

Bernd

______________________________________________
Meteorite-list mailing list
Meteorite-list_at_meteoritecentral.com
http://www.pairlist.net/mailman/listinfo/meteorite-list
Received on Mon 25 Feb 2002 03:25:09 PM PST