Grant Cawthorn Bushveld Complex Grant cawthorn, rffiliation aaschool of geosciences, university of the witwatersrand, po wits, 2050, in the case of the bushveld complex, several km of hot, dense magma intruded into lowdensity sandstones and shalesalong a strike length of 160 km in the western bushvelduch changes indie that there was topographic relief.