This award supports the study of rocks of Jurassic age (Ferrar Group) which cap the Gondwana sedimentary sequence in Antarctica and are interpreted to be a manifestation of the thermal processes associated with supercontinent breakup. Correlative magmatism is recorded in Australia and southern Africa. The age of crystalization of all these igneous rocks is not well established because of the difficulties in age determination of tholeiites and altered silicic rocks. Recent work on feldspar separates suggests that at least the Ferrar lavas may be older that currently accepted. The results will have implications for: (1) petrogenesis of the Ferrar rocks; (2) age relations of Ferrar magmatic along the Transantarctic Mountains; (3) temporal and spatial relations between magmatic events across southern Africa-Antarctica-Australia associated with Gondwana breakup; (4) the tectonic history of the Transantarctic Mountains.