Catalina 629        25.084765°S, 69.908789°W

Antofagasta, Chile

Find: 2019 Nov 07

Classification: Mesosiderite (group A3)

Petrography (E. Jacquet, C. Brillatz, MNHNP): A fresh (<1 vol% weathering phases) recrystallized stone with 59 vol% (point counting with N=504) pyroxene crystals with augite exsolution, up to 1 mm in size (the largest still identifiable as preexisting mineral clasts), anorthitic plagioclase (19 vol%), silica (4 vol%), more or less irregular Fe-Ni (chiefly kamacite) grains up to 2 mm in size (19 vol%), small troilite grains a few 10s of µm across at most (<1 vol%), chromite (<1 vol%), merrillite (<1 vol%) especially enriched in one pyroxene area which may have contained olivine (now absent) prior to metamorphism, trace ilmenite.

Geochemistry: Mineral composition and geochemistry: plagioclase An_90.3±0.3Ab_9.4±0.2Or_0.3±0.1 (N=3); clinopyroxene Fs_14.7±0.3Wo_42.0±0.2 (N=2); orthopyroxene FeO/MnO = 28 (N=3)

Classification: Mesosiderite, group A from plagioclase/pyroxene ratio (see Mittlefehldt et al. 1998), and grade 3 from level of recrystallization (Powe, 1971), with no impact melt evident. Probably paired with Catalina 392 and 399 found nearby (although classified B2, with Catalina 399 having nonetheless 21 vol% plagioclase).