ORIGIN AND ENVIRONMENTAL SIGNIFICANCE OF LARGE-SCALE PATTERNED GROUND, DONNELLY DOME AREA, ALASKA.
Large-scale patterned ground in the Donnelly Dome area of central Alaska consists of polygons 25 to 46 m in diameter bounded by shallow troughs 1 to 2 m wide that form the sides of the polygons. The troughs are underlain by wedge-shaped masses of sediments that extend downward 2 to 3 m. Texture of t...
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ftdtic:AD0474477 2023-05-15T15:09:23+02:00 ORIGIN AND ENVIRONMENTAL SIGNIFICANCE OF LARGE-SCALE PATTERNED GROUND, DONNELLY DOME AREA, ALASKA. Church, Richard E. Pewe, Troy L. Andresen, Marvin J. COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH 1965-06 text/html http://www.dtic.mil/docs/citations/AD0474477 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0474477 en eng http://www.dtic.mil/docs/citations/AD0474477 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Geology Geochemistry and Mineralogy (*PERMAFROST ALASKA) PHYSICAL PROPERTIES TERRAIN STRUCTURAL GEOLOGY ICE GRAVEL SILT SOURCES STRATIGRAPHY ARCTIC REGIONS CLIMATE TEXTURE Text 1965 ftdtic 2016-02-18T17:16:36Z Large-scale patterned ground in the Donnelly Dome area of central Alaska consists of polygons 25 to 46 m in diameter bounded by shallow troughs 1 to 2 m wide that form the sides of the polygons. The troughs are underlain by wedge-shaped masses of sediments that extend downward 2 to 3 m. Texture of the sediments of the wedges is distinct from that of the poorly stratified glacial outwash gravel that the wedges transect. Sediments of the wedge vary texturally along the strike and vertically within a given wedge. The coarsest material in the wedge is about 75 mm in diameter, which is the same size as the coarsest material in the outwash. The fine material in the wedges is silt, the same as that which blankets the area. The patterned ground of the Donnelly Dome area originated during Wisconsin time when the mean annual air temperature was at least 3C colder than now. Wigh the warming of the climate in post-Wisconsin time most of the perennially frozen gravel thawed and the ice wedges melted. The voids created by the melting of the ice wedges were filled with sediment that was washed from the surface or collapsed from the thawed sides of the voids. The troughs bounding the polygons are now, however, no longer underlain with ice wedges but with ice wedge pseudomorphs (fossil ice wedges). (Author) Text Arctic Ice permafrost wedge* Alaska Defense Technical Information Center: DTIC Technical Reports database Arctic Donnelly ENVELOPE(-117.105,-117.105,55.728,55.728) |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Geology Geochemistry and Mineralogy (*PERMAFROST ALASKA) PHYSICAL PROPERTIES TERRAIN STRUCTURAL GEOLOGY ICE GRAVEL SILT SOURCES STRATIGRAPHY ARCTIC REGIONS CLIMATE TEXTURE |
spellingShingle |
Geology Geochemistry and Mineralogy (*PERMAFROST ALASKA) PHYSICAL PROPERTIES TERRAIN STRUCTURAL GEOLOGY ICE GRAVEL SILT SOURCES STRATIGRAPHY ARCTIC REGIONS CLIMATE TEXTURE Church, Richard E. Pewe, Troy L. Andresen, Marvin J. ORIGIN AND ENVIRONMENTAL SIGNIFICANCE OF LARGE-SCALE PATTERNED GROUND, DONNELLY DOME AREA, ALASKA. |
topic_facet |
Geology Geochemistry and Mineralogy (*PERMAFROST ALASKA) PHYSICAL PROPERTIES TERRAIN STRUCTURAL GEOLOGY ICE GRAVEL SILT SOURCES STRATIGRAPHY ARCTIC REGIONS CLIMATE TEXTURE |
description |
Large-scale patterned ground in the Donnelly Dome area of central Alaska consists of polygons 25 to 46 m in diameter bounded by shallow troughs 1 to 2 m wide that form the sides of the polygons. The troughs are underlain by wedge-shaped masses of sediments that extend downward 2 to 3 m. Texture of the sediments of the wedges is distinct from that of the poorly stratified glacial outwash gravel that the wedges transect. Sediments of the wedge vary texturally along the strike and vertically within a given wedge. The coarsest material in the wedge is about 75 mm in diameter, which is the same size as the coarsest material in the outwash. The fine material in the wedges is silt, the same as that which blankets the area. The patterned ground of the Donnelly Dome area originated during Wisconsin time when the mean annual air temperature was at least 3C colder than now. Wigh the warming of the climate in post-Wisconsin time most of the perennially frozen gravel thawed and the ice wedges melted. The voids created by the melting of the ice wedges were filled with sediment that was washed from the surface or collapsed from the thawed sides of the voids. The troughs bounding the polygons are now, however, no longer underlain with ice wedges but with ice wedge pseudomorphs (fossil ice wedges). (Author) |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH |
format |
Text |
author |
Church, Richard E. Pewe, Troy L. Andresen, Marvin J. |
author_facet |
Church, Richard E. Pewe, Troy L. Andresen, Marvin J. |
author_sort |
Church, Richard E. |
title |
ORIGIN AND ENVIRONMENTAL SIGNIFICANCE OF LARGE-SCALE PATTERNED GROUND, DONNELLY DOME AREA, ALASKA. |
title_short |
ORIGIN AND ENVIRONMENTAL SIGNIFICANCE OF LARGE-SCALE PATTERNED GROUND, DONNELLY DOME AREA, ALASKA. |
title_full |
ORIGIN AND ENVIRONMENTAL SIGNIFICANCE OF LARGE-SCALE PATTERNED GROUND, DONNELLY DOME AREA, ALASKA. |
title_fullStr |
ORIGIN AND ENVIRONMENTAL SIGNIFICANCE OF LARGE-SCALE PATTERNED GROUND, DONNELLY DOME AREA, ALASKA. |
title_full_unstemmed |
ORIGIN AND ENVIRONMENTAL SIGNIFICANCE OF LARGE-SCALE PATTERNED GROUND, DONNELLY DOME AREA, ALASKA. |
title_sort |
origin and environmental significance of large-scale patterned ground, donnelly dome area, alaska. |
publishDate |
1965 |
url |
http://www.dtic.mil/docs/citations/AD0474477 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0474477 |
long_lat |
ENVELOPE(-117.105,-117.105,55.728,55.728) |
geographic |
Arctic Donnelly |
geographic_facet |
Arctic Donnelly |
genre |
Arctic Ice permafrost wedge* Alaska |
genre_facet |
Arctic Ice permafrost wedge* Alaska |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/AD0474477 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766340592356294656 |