Geologic framework of the proposed aeromagnetic survey area in the central Transantarctic Mountains. (a) Map of Archean and Proterozoic basement in East Antarctica and location of Nimrod Group in Transantarctic Mountains. (b) General geology of the Nimrod Group in the Miller and Geologists ranges (simplified from Goodge et al. 1993a). (c) General geology of the central Transantarctic Mountains between Byrd and Beardmore glaciers, showing proposed survey area and base camps. Stratigraphic divisions based on new field and geochronologic data in rocks of the Beardmore and Byrd groups (Goodge et al., 2002; Myrow et al., 2002). Contours of depth to bedrock from BEDMAP data (Lythe et al., 2000). Electronic version is in color.