Soils and salt Fretting

Wellman and Wilson have suggested that salt fretting is in important erosive agent where soluble salts are abundant. The Wright Valley is the classic area for the process. The soils were studied in more detail than they had been previously because it is thought that salt fretting within the soils, although less obvious, is more important than the spectacular cavernous weathering of boulders that stand above soil level. Within the area we examined there are at least two main soil types: on arid soil which covers most of the Wright Valley and is never flushed out by water, and a non-arid soil which is flushed out annually by melting snow. The arid soils contain much soluble salt and have well defined horizons. They require detailed study in roder to find the processes that control horizon formation. The uppermost horizon is normally deseribed as being "lag gravels", inferring wind transport of fines. Wind is important but does not explain all the profiels observed.