Petrography and mineral chemistry of Escalón meteorite, an H4 chondrite, Mexico

The Escalón meteorite, a crusted mass weighing 54.3 g, was recovered near Zona del Silencio in Escalón, state of Chihuahua, México. The stone is an ordinary chondrite belonging to the high iron group H, type 4. Electron microprobe analyses of olivine (Fa18.1) and pyroxene (Fs16.5), phosphate, plagioclase, opaque phases, matrix and chondrule glasses are presented. The metal phases present are kamacite (6.08%Ni), taenite (31.66%Ni), high nickel taenite (50.01%Ni) and traces of native Cu. The chondrules average apparent diameter measures 0.62 mm. X-ray diffraction pattern shows olivine, pyroxene and kamacite. Alkaline-type glass is found mainly in chondrules. This meteorite is a stage S3, shock-blackened chondrite with weathering grade W0.