MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 18 Nov 2023
Search for: Search type: Search limits: Display: Publication:
Text help
Starts with
Sounds like
Falls  Non-NWAs
What's new
  in the last:
Limit to approved meteorite names
Search text:  
Allan Hills A81261
Basic information Name: Allan Hills A81261
     This is an OFFICIAL meteorite name.
Abbreviation: ALHA81261
This meteorite may also be called Allan Hills 81261 (ALH 81261) in publications.

Observed fall: No
Year found: 1981
Country: Antarctica [Collected by US Antarctic Search for Meteorites program (ANSMET)]
Mass:help 11.8 g
Antarctic Meteorite Newsletter:  AMN 8(1)  (1985)  H?
AMN 13(1)  (1990)  H?/acapulco-like
AMN 17(1)  (1994)  Acapulco-like
Meteoritical Bulletin:  MB 76  (1994)  Acapulcoite
NHM Catalogue:  5th Edition  (2000)  Acapulcoite
MetBase:  v. 7.1  (2006)  Acapulcoite
Recommended:  Acapulcoite    [explanation]

This is 1 of 91 approved meteorites classified as Acapulcoite.   [show all]
Search for other: Acapulcoite-lodranite family, Acapulcoites, and Primitive achondrites
Writeup from AMN 8(1):

Sample No.: ALHA81261

Location: Allan Hills

Weight (g): 11.8

Field No.: 1255

Dimensions (cm): 2 x 1.5 x 1.5

Meteorite Type: H(?) Chondrite


Macroscopic Description: Roberta Score

Brown and black fusion crust covers 50% of this meteorite fragment. The interior is medium to light gray in color. Metal is abundant. A weathering rind was exposed when the stone was chipped.


Thin Section (,2) Description: Brian Mason

The section shows that this meteorite is an equigranular (grains 0.1-0.4 mm) aggregate of approximately equal amounts of olivine and orthopyroxene, with minor amounts of nickel-iron, plagioclase, troilite, diopside, and accessory chromite. A little limonitic staining is present around metal grains. Microprobe analyses show the minerals are uniform in composition: olivine, Fa11.3; orthopyroxene, Wo2Fs11; plagioclase, An14Or4. This specimen is identical in all respects with ALHA77081, classed as an H(?) meteorite, and the two are almost certainly paired. The mineral analyses are indistinguishable from those of Acapulco (Palme et al., Geochimica et Cosmochimica Acta, 45, p. 728, 1981).

Data from:
  Table 2
  Line 783:
Origin or pseudonym:Main icefield
Mass (g):11.8
Weathering grade:A/B
Fayalite (mol%):11
Ferrosilite (mol%):11
Comments:77081 pairing group
Search for specimens in the Smithsonian Institution collection (U.S.):   
    Require SI photo
Search for this meteorite in the NASA/JSC database (U.S.):   
References: Published in Antarctic Meteorite Newsletter 8(1) (1985), JSC, Houston
Published in Meteoritical Bulletin, no. 76, Meteoritics 29, 100-143 (1994)
Find references in NASA ADS:
Find references in Google Scholar:

     Catalogue of Meteorites:   (76° 43'S, 159° 40'E)
     Recommended::   (76° 41' 28"S, 159° 23' 13"E)
Note: the NHM and MetBase coordinates are 7.7 km apart

     This is 1 of 44248 approved meteorites from Antarctica (plus 3802 unapproved names)
Proximity search:
Find nearby meteorites: enter search radius (km):

Direct link to this page