[meteorite-list] Dong Ujimqin Qi Mesosiderite - Type 1

From: bernd.pauli_at_paulinet.de <bernd.pauli_at_meteoritecentral.com>
Date: Wed Mar 30 15:09:45 2005
Message-ID: <DIIE.0000002D0000361D_at_paulinet.de>

> http://www.meteoriteguy.com/collection/dong-ujimqin.htm

Thanks for letting us enjoy!

.. and, for those who would appreciate some background info:


TAO K. et al. (1996) A Stony-iron meteorite fall from Dongwu Banner, Inner
Mongolia, China, September 7, 1995 (abs. Meteoritics 31, 1996, A139):

A meteorite shower fell at 13:45 hr on September 7, 1995, in the area of Arisileng-
tugacha, 150 km to the SE of the town of Dongwumuqin Banner, Inner Mongolia,
(45? 30' N, 119' E). Three fragments of 88.2 kg (No.1), 38.0 kg (No.2), and 2.6 kg
(No.3) were recovered from a narrow area about 20 km long in the direction north-
south. From their appearance, all three meteorites have fusion crusts in varying
degrees. The meteorite samples of No.2 and No.3 have more well-developed fusion
crusts than No.1. This implies that No.1 may have experienced disruption. From
observations made of the surfaces of the meteorites, although there are some silicate
fragments with diameters about 2-8 cm that were scattered in the meteorites, most
of the metallic minerals and nonmetallic minerals were finely disseminated and were
inhomogeneously distributed. Among the metallic minerals the main component is
kamacite; other components are taenite, troilite, and schreibersite. For nonmetallic
minerals the dominant mineral is olivine; other minerals include pyroxene, plagioclase,
tridymite, stanfieldite, whitlockite, and cordierite. On the basis of its macroscopic
petrographic texture, the silicate-to-metallic mineral facies has a ratio of about 1:1.
Olivine is brecciform surrounded by numerous fine-grained crystals. The grains of pyroxene
and plagioclase are irregular. Within grains of kamacite banded taenite occurs, and both
of them constitute a netlike texture. Some fine-grained troilite crystals and fine-grained
prismatic schreibersite crystals occur in kamacite. According to the analyses of mineral
constituents and textures, the Dongwu meteorites were identified as stony-iron meteorites.
Because the Dongwu meteorites have some differences in mineral components and textures
from the typical pallasites and mesosiderites, accurate identification for subgroups needs
further studies.


Best wishes,

Bernd
Received on Wed 30 Mar 2005 03:09:43 PM PST