Adam Thalha [sic]                    22°59.613'N, 10°09.218'W

Mauritania

Find: January 28, 2005

Ordinary chondrite (LL3)

History: Annick Goueslain and Jean Luc Parodi discovered two stones in the Mauritanian Sahara while searching for meteorites.

Physical characteristics: The two fresh-looking stones are partially covered with fusion crust; their masses are 145 and 114.3 g, respectively.

Petrography: (M. Bourot-Denise, MNHN) The chondritic texture is intact, and opaques are present as nodules interspersed between chondrules; large type II chondrules are by far the most abundant among chondrules and very big (0.5->1 cm in size); white, pyroxene chondrules are especially common; in type I porphyritic chondrules, no FeO zoning is seen in olivine. Matrix in between chondrules is most of the time pervaded by a mixture of silicate-, metal-, and sulfide-forming droplets (melted material) in the vicinity of large opaque grains.

Geochemistry: Olivine (Fa_10.4±12.2, range Fa_0.72-39.8; CaO content up to 0.6 and Cr₂O₃ content up to 0.55 [both in wt%]); low-Ca pyroxene (Fs_14.1±6.5, range Fs_4.1-21.2).

Classification: Ordinary chondrite (LL3; estimated subtype 3.2); S4, W2.

Type specimens: A total of 21 g of sample and four polished mounts are on deposit at MNHN. In addition, MNHN holds a nearly complete stone of 120.8 g. Goueslain and Parodi hold the remaining mass.