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 (AMS), geochronological and geochemical
investigations completed under the British Antarctic Survey’s MAMOG project have provided some of the answers.
Across most of the area, magma volumes were small compared to those in southern Africa. Jurassic dikes intruding the
Archean craton are sparse and the Jutulstraumen trough, a Jurassic rift, is interpreted, from aerogeophysical data, as
largely amagmatic. The largest volumes of magma were emplaced along the margin of the craton and close to the
Africa-Antarctica rift. Although dikes were emplaced by both vertical and horizontal flow, overwhelmingly magmas in
Dronning Maud Land were locally derived, and not emplaced laterally from distant sources. Basaltic magmatism was
protracted in Dronning Maud Land (several dike emplacement episodes between ~206 and 175 Ma), and the small
magma volumes resulted in highly diverse magma compositions, including picrites and ferropicrites interpreted to have
been derived from hot mantle in a mantle plume. The protracted magmatism before the locally ~177 Ma flood lava
eruptions, and evidence for a radiating dike swarm, favor a model of mantle plume incubation for 20-30 million years
before flood lava eruption.
