Sample No.: ALHA81009

Location: Allan Hills

Field No.: 1500

Weight (gms): 229.0

Meteorite Type: Eucrite

Physical Description: Roberta Score

ALHA81009 is completely covered with flow marked black fusion crust. Contained in the light-gray matrix are numerous clasts which are as large as .5 cm in diameter. Oxidation haloes are present. Dimensions: 7 x 5.5 x 3.5 cm.

Petrographic Description: Brian Mason

The section consists largely of brown grains of pigeonite up to 1 mm and colorless grains of plagioclase up to 2 mm in a comminuted groundmass of these minerals. Some lithic clasts, up to 3 mm across, are present; most are fine-grained, but a few have coarse gabbroic textures. No evidence of weathering is visible. Microprobe analyses show pyroxene compositions ranging fairly continuously from Wo4En33Fs63 to Wo40En26Fs30; En content shows a limited range (28-37) except for one grain Wo6En47Fs47. Plagioclase composition range is An75-93, mean An86. The meteorite is a eucrite, but it differs from previously described polymict eucrites from the Allan Hills in the range and distribution of pyroxene compositions.

[From AMN 7(1):] ALHA81009 Clasts

Several interesting clasts were discovered while processing ALHA81009 (Eucrite). They are now available for allocation. 1) Dark clast with light inclusions; 2) Light gray clast with white and yellowish minerals; 3) Gray area with no clasts. Requests for these specific clasts may be made to the MWG.