Semdimentological Analysis of the Western Terminus Region of the Matanuska Glacier, Alaska
Sedimentation at the terminus of the Matanuska Glacier has been found to be primarily subaerial in a 100- to 300-m wide, ice-cored zone paralleling the edge of the active ice. Certain physical and chemical characteristics of the ice and debris of the superglacial, englacial and basal zones of the gl...
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ftdtic:ADA072000 2023-05-15T16:20:27+02:00 Semdimentological Analysis of the Western Terminus Region of the Matanuska Glacier, Alaska Lawson,Daniel E COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH 1979-05 text/html http://www.dtic.mil/docs/citations/ADA072000 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA072000 en eng http://www.dtic.mil/docs/citations/ADA072000 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Geology Geochemistry and Mineralogy Snow Ice and Permafrost *GLACIERS *SEDIMENTOLOGY DEBRIS ALASKA SEDIMENT TRANSPORT DRAINAGE MELTING GLACIAL GEOLOGY Matanuska glacier PE61102A AST24 WU002 Text 1979 ftdtic 2016-02-20T16:34:37Z Sedimentation at the terminus of the Matanuska Glacier has been found to be primarily subaerial in a 100- to 300-m wide, ice-cored zone paralleling the edge of the active ice. Certain physical and chemical characteristics of the ice and debris of the superglacial, englacial and basal zones of the glacier indicate the debris of the basal zone, the primary source of sediment, is entrained during freeze-on of meltwater, probably surficially derived, to the glacier sole. Till formation results from the melting of buried ice of the basal zone. Melt-out till inherits the texture and particle orientations of basal ice debris; other properties are not as well preserved. Most deposits result from resedimentation of till and debris by sediment gravity flows, meltwater sheet and rill flow, slump, spall, and ice ablation. Depositional processes are interrelated in the process of backwasting of ice-cored slopes. Sediment flows are the primary process of resedimentation. Their physical characteristics, multiple mechanisms of flow and deposition, and characteristics of their deposits vary with the water content of the flow mass. Deposits of each process are distinguished from one another by detailed analysis of their internal organization, geometry and dimensions, and the presence of other internal and related external features. Genetic facies are defined by these characteristics. The interrelationship of processes develops a composite depositional sequence defined in terms of genetic facies associations; an upper, resedimented facies association, a middile, till facies association, and a lower, subglacial-resedimental facies association. The lateral and vertical distribution of genetic facies within the associations is mainly nonrepetitive. Text glacier glaciers Ice permafrost Alaska Defense Technical Information Center: DTIC Technical Reports database |
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Open Polar |
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Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Geology Geochemistry and Mineralogy Snow Ice and Permafrost *GLACIERS *SEDIMENTOLOGY DEBRIS ALASKA SEDIMENT TRANSPORT DRAINAGE MELTING GLACIAL GEOLOGY Matanuska glacier PE61102A AST24 WU002 |
spellingShingle |
Geology Geochemistry and Mineralogy Snow Ice and Permafrost *GLACIERS *SEDIMENTOLOGY DEBRIS ALASKA SEDIMENT TRANSPORT DRAINAGE MELTING GLACIAL GEOLOGY Matanuska glacier PE61102A AST24 WU002 Lawson,Daniel E Semdimentological Analysis of the Western Terminus Region of the Matanuska Glacier, Alaska |
topic_facet |
Geology Geochemistry and Mineralogy Snow Ice and Permafrost *GLACIERS *SEDIMENTOLOGY DEBRIS ALASKA SEDIMENT TRANSPORT DRAINAGE MELTING GLACIAL GEOLOGY Matanuska glacier PE61102A AST24 WU002 |
description |
Sedimentation at the terminus of the Matanuska Glacier has been found to be primarily subaerial in a 100- to 300-m wide, ice-cored zone paralleling the edge of the active ice. Certain physical and chemical characteristics of the ice and debris of the superglacial, englacial and basal zones of the glacier indicate the debris of the basal zone, the primary source of sediment, is entrained during freeze-on of meltwater, probably surficially derived, to the glacier sole. Till formation results from the melting of buried ice of the basal zone. Melt-out till inherits the texture and particle orientations of basal ice debris; other properties are not as well preserved. Most deposits result from resedimentation of till and debris by sediment gravity flows, meltwater sheet and rill flow, slump, spall, and ice ablation. Depositional processes are interrelated in the process of backwasting of ice-cored slopes. Sediment flows are the primary process of resedimentation. Their physical characteristics, multiple mechanisms of flow and deposition, and characteristics of their deposits vary with the water content of the flow mass. Deposits of each process are distinguished from one another by detailed analysis of their internal organization, geometry and dimensions, and the presence of other internal and related external features. Genetic facies are defined by these characteristics. The interrelationship of processes develops a composite depositional sequence defined in terms of genetic facies associations; an upper, resedimented facies association, a middile, till facies association, and a lower, subglacial-resedimental facies association. The lateral and vertical distribution of genetic facies within the associations is mainly nonrepetitive. |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH |
format |
Text |
author |
Lawson,Daniel E |
author_facet |
Lawson,Daniel E |
author_sort |
Lawson,Daniel E |
title |
Semdimentological Analysis of the Western Terminus Region of the Matanuska Glacier, Alaska |
title_short |
Semdimentological Analysis of the Western Terminus Region of the Matanuska Glacier, Alaska |
title_full |
Semdimentological Analysis of the Western Terminus Region of the Matanuska Glacier, Alaska |
title_fullStr |
Semdimentological Analysis of the Western Terminus Region of the Matanuska Glacier, Alaska |
title_full_unstemmed |
Semdimentological Analysis of the Western Terminus Region of the Matanuska Glacier, Alaska |
title_sort |
semdimentological analysis of the western terminus region of the matanuska glacier, alaska |
publishDate |
1979 |
url |
http://www.dtic.mil/docs/citations/ADA072000 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA072000 |
genre |
glacier glaciers Ice permafrost Alaska |
genre_facet |
glacier glaciers Ice permafrost Alaska |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA072000 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766008373762850816 |