A polygon outlined by sand wedges underlying its boundaries.
Sand-filled polygon; Soil-wedge polygon (not recommended: tessellation, tundra polygon, “Taimyr” polygon)
Sand-filled frost-fissure polygon net. Similar to ice-wedge polygons, their troughs have raised rims.
On Earth, open cracks can be 1–100 mm wide, 2–5 m or more deep, and 1 m to several tens of meters long (Mackay 1974; Murton 1996). Typical is a raised rim on either side of the fissure. Sometimes the rim may be as much as 0.5–1.0 m high. In plain view, the cracks form orthogonal or non-orthogonal networks, according to the kind of angles where cracks or their projections intersect, and complete or incomplete, depending on whether the cracks join (Lachenbruch 1962). Polygon diameter varies from a few meters to >100 m.
Primary filling (this entry)
- Fábián SÁ, Kovács J, Tarnocai C, Varga G (2009) Similarities between the recent permafrost in north-western Canada and the Pleistocene relict cryogenic forms in Central Europe (Hungary). In: Krugger M, Stern HP (eds) New permafrost and glacier research. Nova, New York, pp 107–129Google Scholar
- Harris SA, French HM, Heginbottom JA, Johnston GH, Ladanyi B, Sego DC, van Everdingen RO (eds) (1988) Glossary of permafrost and related ground-ice terms, Technical memorandum no 142. Permafrost Subcommittee, National Research Council of Canada, OttawaGoogle Scholar
- Lachenbruch AH (1962) Mechanics of thermal contraction cracks and ice-wedge polygons in permafrost. U.S. Geological Survey, Special paper 70, 69 pGoogle Scholar
- Levy JS, Head JW, Marchant DR (2011) Gullies, polygons and mantles in Martian permafrost environments: cold desert landforms and sedimentary processes during recent Martian geological history. In: Martini IP, French HM, Pérez Alberti A (eds) Ice-marginal and periglacial processes and sediments, Special publications, 354. Geological Society, London, pp 167–182Google Scholar
- Mellon MT, Searls ML, Martinez-Alonso S et al (2007) HIRISE observations of patterned ground on Mars. In: Seventh international conference on Mars #3285. Pasadena, California, USAGoogle Scholar
- Murton JB (1996) Morphology and paleoenvironmental significance of quaternary sand veins, sand wedges and composite wedges, Tuktoyaktuk Coastlands, Western Arctic Canada. J Sediment Res 66:17–25Google Scholar
- van Everdingen R (ed) (1998, revised May 2005) Multi-language glossary of permafrost and related ground-ice terms. National Snow and Ice Data Center/World Data Center for Glaciology, BoulderGoogle Scholar
- Washburn AL (1979) Geocryology. Edward Arnold, London, 406 pGoogle Scholar