Nature and genesis of mudboils, central Keewatin, Canada
Mudboils are round lo elongate, 1–3 m diameter bare soil patches that form on perennially frozen till, marine clayey silt, colluvium, or other poorly sorted sediments (muds) with significant silt and (or) clay content. In Keewatin these muds have low liquid limits (< 20%) and limited plasticity i...
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1978
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crcansciencepubl:10.1139/e78-113 2024-09-09T19:44:38+00:00 Nature and genesis of mudboils, central Keewatin, Canada Shilts, William W. 1978 http://dx.doi.org/10.1139/e78-113 http://www.nrcresearchpress.com/doi/pdf/10.1139/e78-113 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 15, issue 7, page 1053-1068 ISSN 0008-4077 1480-3313 journal-article 1978 crcansciencepubl https://doi.org/10.1139/e78-113 2024-07-25T04:10:06Z Mudboils are round lo elongate, 1–3 m diameter bare soil patches that form on perennially frozen till, marine clayey silt, colluvium, or other poorly sorted sediments (muds) with significant silt and (or) clay content. In Keewatin these muds have low liquid limits (< 20%) and limited plasticity indices (< 10%). Natural moisture contents are very near the liquid limit so that the muds liquefy and flow readily in response to slight changes in moisture content or slight internal or external stresses. When the stresses cannot be readily relieved by downslope movement, mud may burst through a rigid surface layer or carapace, creating or maintaining a mudboil.Ideally, the structures of a mudboil include: (1) an outer turf or stone ring, the type of ring depending on the stoniness of the mud and severity of the climate; (2) a thawed mud substrate (TMS), lying between the permafrost table and a rigid surface layer; (3) a carapace, a semi-rigid, sandy, desiccated layer averaging 30–40 cm thick; and (4) a diapir, in the case of active mudboils, which marks a zone of intrusion of mud from the TMS through the carapace.Driving pressures for diapirism may result from hydrostatic or artesian pressures on a slope, from excess pore-water pressures due to rain or thawing ice lenses, or from loading by animals or man.The shapes of mudboils are controlled principally by slope, the steeper the slope, the more elongate the boil; the nature of their borders depends on the texture of mud, its thickness over bedrock, exposure to tundra fires, and on the suitability of local climate for growth of vegetation.The degree of activity of a mudboil is largely related to the amount of clay and silt in the mud, the steepness of the slope on which it is located, and the amount of moisture available to the mud during the thaw season. Article in Journal/Newspaper Ice Keewatin permafrost Tundra Canadian Science Publishing Canada Boil The ENVELOPE(161.533,161.533,-74.150,-74.150) The Boil ENVELOPE(-57.443,-57.443,-63.496,-63.496) Canadian Journal of Earth Sciences 15 7 1053 1068 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
Mudboils are round lo elongate, 1–3 m diameter bare soil patches that form on perennially frozen till, marine clayey silt, colluvium, or other poorly sorted sediments (muds) with significant silt and (or) clay content. In Keewatin these muds have low liquid limits (< 20%) and limited plasticity indices (< 10%). Natural moisture contents are very near the liquid limit so that the muds liquefy and flow readily in response to slight changes in moisture content or slight internal or external stresses. When the stresses cannot be readily relieved by downslope movement, mud may burst through a rigid surface layer or carapace, creating or maintaining a mudboil.Ideally, the structures of a mudboil include: (1) an outer turf or stone ring, the type of ring depending on the stoniness of the mud and severity of the climate; (2) a thawed mud substrate (TMS), lying between the permafrost table and a rigid surface layer; (3) a carapace, a semi-rigid, sandy, desiccated layer averaging 30–40 cm thick; and (4) a diapir, in the case of active mudboils, which marks a zone of intrusion of mud from the TMS through the carapace.Driving pressures for diapirism may result from hydrostatic or artesian pressures on a slope, from excess pore-water pressures due to rain or thawing ice lenses, or from loading by animals or man.The shapes of mudboils are controlled principally by slope, the steeper the slope, the more elongate the boil; the nature of their borders depends on the texture of mud, its thickness over bedrock, exposure to tundra fires, and on the suitability of local climate for growth of vegetation.The degree of activity of a mudboil is largely related to the amount of clay and silt in the mud, the steepness of the slope on which it is located, and the amount of moisture available to the mud during the thaw season. |
format |
Article in Journal/Newspaper |
author |
Shilts, William W. |
spellingShingle |
Shilts, William W. Nature and genesis of mudboils, central Keewatin, Canada |
author_facet |
Shilts, William W. |
author_sort |
Shilts, William W. |
title |
Nature and genesis of mudboils, central Keewatin, Canada |
title_short |
Nature and genesis of mudboils, central Keewatin, Canada |
title_full |
Nature and genesis of mudboils, central Keewatin, Canada |
title_fullStr |
Nature and genesis of mudboils, central Keewatin, Canada |
title_full_unstemmed |
Nature and genesis of mudboils, central Keewatin, Canada |
title_sort |
nature and genesis of mudboils, central keewatin, canada |
publisher |
Canadian Science Publishing |
publishDate |
1978 |
url |
http://dx.doi.org/10.1139/e78-113 http://www.nrcresearchpress.com/doi/pdf/10.1139/e78-113 |
long_lat |
ENVELOPE(161.533,161.533,-74.150,-74.150) ENVELOPE(-57.443,-57.443,-63.496,-63.496) |
geographic |
Canada Boil The The Boil |
geographic_facet |
Canada Boil The The Boil |
genre |
Ice Keewatin permafrost Tundra |
genre_facet |
Ice Keewatin permafrost Tundra |
op_source |
Canadian Journal of Earth Sciences volume 15, issue 7, page 1053-1068 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e78-113 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
15 |
container_issue |
7 |
container_start_page |
1053 |
op_container_end_page |
1068 |
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1809914290589663232 |