Solifluction

Garland-like solifluction formed in the Swiss National Park
Possible solifluction lobes in Acidalia Planitia on Mars as seen by HiRISE

Solifluction is a collective name for gradual mass wasting slope processes related to freeze-thaw activity. This is the standard modern meaning of solifluction, which differs from the original meaning given to it by Johan Gunnar Andersson in 1906.[1][2]

Origin and evolution of the concept

In the original sense it meant the movement of waste saturated in water found in periglacial regions. However it was later discovered that various slow waste movements in periglacial regions did not required saturation in water, but were rather associated to freeze-thaw processes.[1][2] The term solifluction was appropriated to refer to these slow processes, and therefore excludes rapid periglacial movements.[1] In slow periglacial solifluction there are not clear gliding planes,[3] an therefore skinflows and active layer detachments are not included in the concept.[1] On the other hand, movement of waste saturated in water can occurs in any humid climate, and therefore this kind of solifluction is not restricted to cold climates. Slow periglacial solifluction is classified into four types:[1]

Slow solifluction is acts much slower than some geochemical fluxes or than other erosion processes. [1] The relatively low rates at which solifluction operates contrast occurrence over wide mountain areas and periglaciated lowlands.[1][2] Since solifluction is associated to humidity and cold climates it can be used to infer past climates.[1]

Deposits

Deposits of slow periglacial solifluction compromise poorly stratified diamicton and diamicton where stratification is wholly lacking. When stratification can be seen it is often distinguished by a buried organic soil.[3] Some other solifluction deposits that have a more defined stratification consists of alternating layers of diamicton and open-work beds, these last representing buried stone-banked lobes and sheets. A common featurein solifluction deposits is the orientation of clasts parallel to the slope.[3]

Landforms

Extraterrestrial solifluction

It was suggested that solifluction might be active on Mars,[4][5] even relatively recently (within the last few millions years), as observed martian lobates bear many similarities with solifluction lobes known from Svalbard.[5]

See also

Notes

  1. ↑ ”Cryogenic deserption” is a transliteration equivalent to frost creep found in some translated Russian scientific literature.[2]

References

  1. 1 2 3 4 5 6 7 8 Matsuoka, Norikazu (2001). "Solifluction rates, processes and landforms: a global review". Earth-Science Reviews. 55: 107–134.
  2. 1 2 3 4 French, Hugh M. (2007). "Azonal Processes and Landforms". The Periglacial Environment (3rd ed.). John Wiley & Sons Ltd. pp. 225–26. ISBN 978-0-470-86588-0.
  3. 1 2 3 Bertran, Pascal; Texier, Jean-Pierre (1999). "Facies and microfacies of slope deposits". Catena. 35: 99–121.
  4. ↑ Mangold, Nicolas. "High latitude patterned grounds on Mars: Classification, distribution and climatic control". Icarus. 174 (2): 336–359. doi:10.1016/j.icarus.2004.07.030.
  5. 1 2 Johnsson, A.; Reiss, D.; Hauber, E.; Zanetti, M.; Hiesinger, H.; Johansson, L.; Olvmo, M. (March 2012). "Periglacial mass-wasting landforms on Mars suggestive of transient liquid water in the recent past: Insights from solifluction lobes on Svalbard". Icarus. 218 (1): 489–505. doi:10.1016/j.icarus.2011.12.021.
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