Yumenguan 001        40.350°N, 93.520°E

Xinjiang, China

Find: 2022 Mar 21

Classification: Ordinary chondrite (LL5, melt breccia)

History: Discovered by Ashanjiang Mahemuti on March 21, 2022, in the desert near Lop Nur, Xinjiang Province, China and shortly thereafter acquired by Ziyao Wang.

Physical characteristics: One large stone (806 g) plus 8 small pieces. The stones are very dark brown and coated with a glossy desert patina. Interior cut surfaces display small light brown clasts in a dark, almost black matrix.

Petrography: (A. Irving, UWS and P. Carpenter, WUSL) Breccia composed of small lithic Type 5 chondrite clasts plus some dicrete equilibrated chondrules within an opaque, very fine-grained matrix (~50 vol.%). The clasts consist of sparse well-formed, equilibrated chondrules containing devitrified glass and plagioclase within a relatively coarse grained matrix containing extensively altered kamacite, taenite, low-Ti chromite, troilite and merrillite. The fine-grained melt matrix contains tiny blebby grains of kamacite and troilite. Clasts have shock stage S3.

Geochemistry: Olivine (Fa_28.6±0.4, range Fa_28.3-29.3, N = 5), low-Ca pyroxene (Fs_23.8±0.2Wo_1.4±0.1, range Fs_23.6-24.1Wo_1.2-1.5, N = 4), augite (Fs_9.0±0.6Wo_44.4±0.9, range Fs_8.5-9.4Wo_45.0-43.7, N = 2), plagioclase in chondrule groundmasses (Ab_58.9-77.6An_25.1-14.7Or_16.2-7.7, N = 2).

Classification: Ordinary chondrite (LL5-melt breccia).

Specimens: 39.2 g including one polished thin section at UWB; remainder with WangZ.