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Grosvenor Mountains 95522
Basic information Name: Grosvenor Mountains 95522
     This is an OFFICIAL meteorite name.
Abbreviation: GRO 95522
Observed fall: No
Year found: 1995
Country: Antarctica [Collected by US Antarctic Search for Meteorites program (ANSMET)]
Mass:help 963 g
Classification
  history:
Antarctic Meteorite Newsletter:  AMN 19(2)  (1996)  Iron-octahedrite
Meteoritical Bulletin:  MB 82  (1998)  Iron
NHM Catalogue:  5th Edition  (2000)  IIIAB
MetBase:  v. 7.1  (2006)  IIIAB
Recommended:  Iron, IIIAB    [explanation]

This is 1 of 311 approved meteorites classified as Iron, IIIAB.   [show all]
Search for other: IIIAB irons, Iron meteorites, and Metal-rich meteorites
Writeuphelp
Writeup from AMN 19(2):
Sample No.: GRO95522
Location: Grosvenor Mountains
Dimensions (cm):   9.4 x 8.0 x 3.0
Weight (g): 962.3
Meteorite Type: Iron - Medium to Coarse Octahedrite
    GRO95522

Macroscopic Description: Roy S. Clarke, Jr.

This specimen is an irregular-shaped oval with a smooth anterior surface and a comparatively rough and irregular posterior. The gentle rounding of the anterior surface suggests oriented flight during atmospheric passage. A thin film of reddish brown to black secondary oxides covers the specimen. The internal Widmanstatten pattern stands out in slight relief over much of the anterior surface, while the posterior surface is irregular, and contains depressions apparently due to terrestrial corrosion.

Polished Section Description: Roy S. Clarke, Jr.

A median slice perpendicular to both the long axis of the oval and an approximated plane of the posterior surface was removed, producing butts of 698 g and 170 g, and a slice of 49 g. A 2.5 cm2 piece was taken for a metallographic section. Fusion crust is absent except for a small accumulation of melt crust on the posterior surface at the rim with the anterior surface. Its maximum width is ~0.3 mm near the union of the surfaces, and it tapers to nothing by 5 mm into the interior. The slice is bordered with a heat-altered zone of ~3 mm on the anterior surface, and of generally narrower and more variable widths on the posterior surface. The plane of cut revealed three directions of the Widmanstatten pattern unequally displayed. Kamacite band widths are ~ 1.3 mm. The kamacite contains Neumann bands, many of which show mild preterrestrial distortion, as do the kamacite bands themselves. Rhabdites are not prominent, but grain-boundary schreibersite and some taenite-border schreibersite are present. Several morphologies of taenite-plessite are present. Close to the anterior surface within an area of fairly high structural distortion is a shattered, euhedral chromite (1.7 x 0.5 mm) surrounded by ~0.4 mm of troilite along the long dimension and ~0.8 at the ends. The exterior of the troilite is bordered over part of its outer edge with schreibersite, and where it is in contact with kamacite, it appears to have been partially melted. Both GRO95511 and GRO95522 are similar in appearance and weathering history. Their Widmanstatten patterns are revealed on different planes, and they have different exposures to preterrestrial distortion and heating. This makes it difficult to suggest if they represent two separate falls or are individuals from a shower. Definitive classification and pairing information awaits trace element analysis.

Data from:
  MB82
  Table A1
  Line 156:
Origin or pseudonym:Outer Cecily
Mass (g):962.5
Class:Iron
Catalogs:
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References: Published in Antarctic Meteorite Newsletter 19(2) (1996), JSC, Houston
Published in Meteoritical Bulletin, no. 82, MAPS 33, A221-A240 (1998)
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Photos:
CreditPhotos
Photographs from AMN:
Photograph from unknown source A photo is in the write-up above
Photos from the Encyclopedia of Meteorites:
courtesy Dr Carlton Allen, JSC-KT, NASA   
Geography:

Antarctica
Coordinates:
     Catalogue of Meteorites:   (85° 40'S, 175° 0'E)
     Recommended::   (85° 40'S, 175° 0'E)

Statistics:
     This is 1 of 39173 approved meteorites from Antarctica (plus 5051 unapproved names)
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