The Fosdick Mountains, West Antarctica, form an 80 × 15 km migmatite dome comprising massive paragneisses that exhibit polyphase fabrics, nappe-scale folds that involve granodiorite to leucogranite intrusions, and diatexite. High strain zones developed on the NE flank of the dome. Multiple generations of leucogranite sheets, dikes and diatexite intrude the dome, and evidence for partial melt in structural sites is widespread. Macroscopic folds and the maximum anisotropy of magnetic susceptibility (AMS) direction are oriented NE-SW, generally parallel with the N65W regional finite strain axis determined from brittle faults and a mafic dike array outside the dome. The direction is...