The Jurassic Karoo large igneous province (LIP) of Antarctica, and its conjugate margin in southern Africa, is critical for investigating important questions about the relationship of basaltic LIPs to mantle plumes. Detailed aerogeophysical, structural, anisotropy of magnetic susceptibility, geochronological and geochemical investigations completed under the British Antarctic Survey's MAMOG project have provided some of the answers. Magma volumes were small compared to those in Africa. Jurassic dikes intruding the Archean craton are sparse and the Jutulstraumen trough, a Jurassic rift, is largely amagmatic. Dikes were emplaced by both vertical and horizontal flow, but overwhelmingly magmas were locally derived, and not emplaced laterally from distant sources. Basaltic magmatism was protracted, and the small magma volumes resulted in diverse compositions, including ferro-picrites interpreted to have been derived from a hot mantle plume. The protracted magmatism before the local flood eruptions favor a model of mantle plume incubation for 20-30 million years.