Grove Mountains 052382                             72°47'15''S, 75°16'38''E

Grove Mountains, Antarctica

Find: 17 January 2006

Achondrite (ureilite)

History and Physical characteristics: The meteorite (1.86 g) was found in a large moraine west to the north segment of the Gale Escarpment in Grove Mountains by J. Li. It has a small, bean-like shape of 17 × 17 mm with a flat bottom, which is almost completely covered by black fusions crust. It is hemispherical in shape with a flat bottom, but completely covered by black fusion crust.

Petrography: (B. Miao, Y. Lin, S. Hu, and L. Feng, IGGCAS). It consists mainly of olivine, pigeonite, and carbonaceous material containing graphite and diamond. Olivine grains are heavily shocked into small grains of 10- 20 µm and shows fine-grained mosaic or granoblastic texture, small amount of glassy material occurs among the fine-grained olivines. Based on the carbonaceous material distribution and reduction zones of olivine, the original outlines of coarse-grained olivine (0.5-1.2 mm) can be readily defined. Reduction zones of olivine, which consist of forsterite and poor-Ni Fe metal, occur near the carbonaceous patches, Many pigeonite grains have rounded shapes with the size of 0.3-0.8 mm. Diamond and graphite were identified in carbonaceous material by Raman.

Mineral compositions and Geochemistry: Olivine (cores = Fa_14.2-22.7; rims = Fa_2.1-13.2), pigeonite (Fs_10.6-14.0Wo_2.1-9.2), augite (Fs_9.6-11.4Wo_19.8-22.8), metal (Ni = 0.8-6.5%, Co = 0.56%).

Classification: Achondrite (ureilite), heavily shocked, minor weathering.

Type specimens: PRIC holds the main mass and a polished section.