header
  MetSoc Home            Publications            Contacts  
Search the Meteoritical Bulletin Database
Last update: 20 Oct 2019
Search for: Search type: Search limits: Display: Publication:
Names
Text help
Places
Classes
Years
Contains
Starts with
Exact
Sounds like
NonAntarctic
Falls  Non-NWAs
What's new
  in the last:
Limit to approved meteorite names
Search text:  
Allan Hills A77002
Basic information Name: Allan Hills A77002
     This is an OFFICIAL meteorite name.
Abbreviation: ALHA77002
This meteorite may also be called Allan Hills 77002 (ALH 77002) in publications.

Observed fall: No
Year found: 1977
Country: Antarctica [Collected jointly by ANSMET (US) and NIPR (Japan)]
Mass:help 235 g
Classification
  history:
Antarctic Meteorite Newsletter:  AMN 1(1)  (1978)  L5
Meteoritical Bulletin:  MB 76  (1994)  L5
NHM Catalogue:  5th Edition  (2000)  L5
NIPR Catalogue:  2000 Edition  (2000)  L5
MetBase:  v. 7.1  (2006)  L5
Recommended:  L5    [explanation]

This is 1 of 6534 approved meteorites (plus 4 unapproved names) classified as L5.   [show all]
Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Writeuphelp
Writeup from AMN 4(1):

Sample No.: ALHA77002

Location: Allan Hills

Field No.: 77122927

Weight (gms): 235.2

Meteorite Type: L5 Chondrite

 

Physical Description:

Specimen reasonably angular with complete, brownish-black fusion crust which shows appreciable weathering. No broken surfaces to indicate crustal thickness. One large fracture. A few chipped corners show appreciable rusting. Specimen is approximately 6.5 x 4.5 cms in dimension.

 

Petrographic Description:

The meteorite is classified as an L5 chondrite. Chondrules are prominent and well-defined, 0.3-0.6 mm in diameter; most are porphyritic olivine, some fine-grained pyroxene. The matrix is dominantly olivine, in angular grains up to 1.0 mm in maximum dimension, with lesser amounts of orthopyroxene. Minor minerals in the matrix are nickel-iron, troilite, and chromite; plagioclase is present as very small grains difficult to recognize. The section is stained brown with limonitic materials and the metal grains are corroded evidently by terrestrial weathering, troilite is unaffected. Microprobe analyses show uniform composition in the olivine (Fa25) and orthopyroxene (Wo1.2 En77 Fs22), plagioclase composition averages Ab84An10 Or6, but appears somewhat variable.

Data from:
  MB76
  Table 2
  Line 11:
Origin or pseudonym:Main icefield
Mass (g):235.2
Class:L5
Weathering grade:B
Fayalite (mol%):25
Ferrosilite (mol%):22
Comments:26Al=30±3; NTL=17.2±0.4
Catalogs:
Search for specimens in the Smithsonian Institution collection (U.S.):   
    Require SI photo
Search for this meteorite in the NIPR database (Japan):   
Search for this meteorite in the NASA/JSC database (U.S.):   
References: Published in Antarctic Meteorite Newsletter 4(1) (1981), JSC, Houston
Published in Meteoritical Bulletin, no. 76, Meteoritics 29, 100-143 (1994)
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Antarctica
Coordinates:
     Catalogue of Meteorites:   (76° 43'S, 159° 40'E)
     Recommended::   (76° 43'S, 159° 40'E)

Statistics:
     This is 1 of 39173 approved meteorites from Antarctica (plus 5051 unapproved names)
Proximity search:
Find nearby meteorites: enter search radius (km):

Direct link to this page