Ureilite - Dhofar 836 Oman

Found 2000 August 15 

An oriented stone with large greenish olivine clasts (split into two pieces) weighing together 995gram was found by

an anonymous finder in August 2000 in the Dhofar region of Oman.

Mineralogy and classification (H. Takeda, Chiba; T. Ishii and M.  Ohtsuki, UTok.): coarse (1-2 mm), equigranular olivine (Fo79 core; Fo90 rim) and pigeonite (Ca10Mg74Fe16 to Ca11Mg71Fe19). Carbonaceous

matter occurs as narrow, intergranular veins. Weakly shocked (S1), with rare mosaicism in olivine. W1.

Specimens: type specimen 20.2 g NSMT;

Dho 836 is not paired with Dho 837, the two specimens differ in composition and texture. Dho 837 has some textural similarities to Dhofar 295, but as the two specimens have very different Fe atomic %. The PTSs of the Dhofar ureilites were studied by an optical microscope and an electron probe micro-analyzer (EPMA    ) at Ocean Res. Inst. (ORI) of Univ. of Tokyo. The Area Analysis technique of the JEOL 8900 EPMA was applied to obtain elemental distribution maps at ORI. A mineral distribution

map of each PTS was constructed by combining the elemental maps. The modal abundance (vol. %) of

silicate minerals was derived from these maps. Chemical compositions of minerals were obtained

with EPMA, JEOL JCXA-733 at ORI with WDS.