Anticyclone, glacial, [284].
Ants, factor in rock decomposition, [156].
Apron, alluvial, [213].
Aprons, outwash, [280], [281].
Arbenz, P., cited, [195].
Arches, of folded strata, [42];
Architecture, of fractured earth superstructure, [55].
Arctic depression, [17].
Areal geological map, [62].