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Thermokarst involutions, summer island, pleistocene mackenzie delta, Western Canadian arctic
Author(s) -
Murton Julian B.,
French Hugh M.
Publication year - 1993
Publication title -
permafrost and periglacial processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.867
H-Index - 76
eISSN - 1099-1530
pISSN - 1045-6740
DOI - 10.1002/ppp.3430040304
Subject(s) - thermokarst , permafrost , geology , buoyancy , liquefaction , geomorphology , ice wedge , pleistocene , fluidization , holocene , arctic , pore water pressure , delta , oceanography , geotechnical engineering , paleontology , aerospace engineering , physics , quantum mechanics , fluidized bed , engineering , waste management
Thermokarst involutions form primarily by loading, buoyancy and water‐escape during the degradation of ice‐rich permafrost. In the Summer Island area of the Pleistocene Mackenzie Delta, they are formed mainly by loading and buoyancy, and occur within a Late Wisconsinan‐Early Holocene thaw layer. Involutions formed by water‐escape (fluidization) occur within slump‐floor deposits. To form thermokarst involutions, ice‐rich permafrost must thaw, drainage conditions must be poor and sediments must vary in texture or composition. In addition, the sediments should be susceptible to fluidization, liquefaction or hydroplastic deformation. Thermokarst involutions formed by loading and buoyancy require a reverse density gradient; those formed by fluidization require open‐system groundwater conditions or associated water‐saturated sediments susceptible to liquefaction.