The Bureau of Mineral Resources proposed aeromagnetic survey during 1968 covering the western Musgrave Block in South Australia includes MANN and portions of the WOODROFFE, BIRKSGATE and LINDSAY 1:250 000 mapsheet areas. Topographic features in the region vary in elevation between about 4000 feet and 1500 feet above sea level. Crystalline basement comprises granulites, gneisses, metaquartzites of the Musgrave-Mann Metamorphics and associated intrusive granites, and mafic and ultramafic large intrusive bodies of the Giles Complex which are associated with major regional fault and shear structures trending across the northern part of the survey area. The margins of the basement on BIRKSGATE and LINDSAY are probably bounded by major faults or shears. The Officer Basin reaches its maximum development immediately south of the survey area. The basin sediments are Ordovician(?), Cambrian and Adelaidean. Adelaidean sandstones overlap with major unconformity the crystalline basement along the southern flank of the Officer Basin.