Sastrugi breaking equipment—ripples and waves are often undercut and the surface is hard and unforgiving, with constant minor topographic changes between ridge and trough. The words "sastrugi" and "zastrugi" are Russian-language plurals; the singular is "sastruga" or "zastruga". The form "sastruga" started as the German-language transliteration of the Russian word заструга (plural: заструги). A Latin-type analogica singular "sastrugus" is used in various writings on exploration of the South Pole, including Robert Falcon Scott's expedition's diaries and Ernest Shackleton's "The Heart of the Antarctic". Under the action of steady wind, free snow particles accumulate and drift like the sand grains in barchan
Origin of the Oak Ridges Moraine a 20 m layer of shallow surface Oak Ridges Moraine sediments, underlain by the "Newmarket Till". The other wedges, which peak at up to 335 m, have thicker and more varied surficial deposits, and the "Newmarket Till" lies deeper below the surface. Moreover, the sedimentary deposits are underlain by "Halton Till" on these wedges, which is not present in the Rice Lake wedge. Thus, from top to bottom, the stratigraphy of the moraine is: The most accepted theory of the development of the Oak Ridges Moraine is that proposed by Barnett et al. (1998). "Moraine development is highlighted in four