Structures at the base of the Upper Group 2 chromitite layer, Bushveld Complex, South Africa, on Karee Mine (Lonmin Platinum)

Several possible processes are reviewed for the origin of these irregularities, especially the small-scale structures, but none explains all the features noted. These processes include remelting, diapirism, impact-generated dimpling, gas escape, and interference rippling. We present a photographic record of these structures, but present no definitive model for their interpretation.