Nonsorted polygons in Victoria Land are usually 10 to 30m in diameter and have associated wedges 20 to 1,000cm wide. The most common wedge filling is a composite of ice, sand, or rubble. The wedges go through a predictable sequence of growth, which is reflected at the surface. Preliminary measurements of growth rates of 0.5 to 3.6mm.yr for wedges in Victoria Land permit dating of various geomorphic surfaces. Results for recent surfaces appear to be good and in agreement with dates derived from lichen studies, but they vary marketly from C-14 dates. Dates of 500 yr for moraine in front of the Hobbs Glacier and 1,300 yr for a terrace in Wright Valley indicate that the last glaciation is more recent than previously thought. Although dating by polygonal ground is still subject to uncertainties, results do permit the determination of ages of glacial events of an order of magnitude. Where polygons are present, surfaces are less than 10,000 yr old; where they are absent and the thickness of the surface dry zone exceeds 1m, surfaces may be older.