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The Binningup H5 Chondrite: A New Fall from Western Australia
Authors:A W R Bevan  K J McNamara  J C Barton
Abstract:Abstract— Following a brilliant daylight fireball at 10:10 a.m. (local time) on 30 September 1984, a single stone weighing 488.1 grams was recovered from Binningup beach (33°09′23″S, 115°40′35″E), Western Australia. Data from 23 reported sightings of the fireball indicate an angle of trajectory 20–40° from the horizontal, a flight-path bearing N210°E and an end-point (ca. 32°39′S, 115°54.5′E) at a height of ~20–30 km. A recrystallized chondritic texture and the presence of olivine and low-Ca orthopyroxene with compositions of Fa18.4 (PMD 1.1)and Fs16.1 (PMD 1.1), respectively, show that Binningup is a typical member of the H-group of ordinary chondrites. Uniform mineral compositions and the presence of generally microcrystalline plagioclase feldspar indicate that the meteorite belongs to petrologic type 5. Pervasive fracturing of silicates suggests mild pre-terrestrial shock loading. Measurements (dpm kg?1) of cosmogenic radionuclides including 22Na (61 ± 5), 26Al (49 ± 3) and 54Mn (66 ± 10) indicate a normal history of irradiation.
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