Gubja Meteorite, Bencubbin, Nigeria

In the early evening of April 3, 1984 the meteorite fell in a corn field near the village of Bogga Dingare after a bright fireball was seen with an explosion. Local people hammered the meteorite into many pieces, and most of the material was dispersed. The original mass may have been ~100 kg, but only 12 kg is accounted for. Various pieces have passed thru many hands with inconsistent amounts of weathering. Gujba is the only known CBa fall, but its nature was not known until the CB group had been formally defined using Bencubbin as a prototype. Members of the CBa subgroup are distinguished by their chondrule-like silicates, abundant metal, and virtual lack of refractory inclusions.

The CB group is somewhat of an outlier among Carbonaceous Chondrites, but its chemical affinities to other Carbonaceous and, most especially, its oxygen isotope peculiarities, place it clearly within the larger grouping’s defined boundaries.