Itkillik Glaciation in the Brooks Range, Northern Alaska
During the Itkillik Glaciation the Brooks Range supported an extensive mountain-glacier complex that extended for 750 km between 141° and 158°W longitude. Individual ice streams and piedmont lobes flowed as much as 50 km beyond the north and south margins of the range. Glaciers in the southern Brook...
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Cambridge University Press (CUP)
1975
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crcambridgeupr:10.1016/0033-5894(75)90012-5 2024-10-13T14:06:27+00:00 Itkillik Glaciation in the Brooks Range, Northern Alaska Hamilton, Thomas D. Porter, Stephen C. 1975 http://dx.doi.org/10.1016/0033-5894(75)90012-5 http://api.elsevier.com/content/article/PII:0033589475900125?httpAccept=text/xml http://api.elsevier.com/content/article/PII:0033589475900125?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400031616 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Quaternary Research volume 5, issue 4, page 471-497 ISSN 0033-5894 1096-0287 journal-article 1975 crcambridgeupr https://doi.org/10.1016/0033-5894(75)90012-5 2024-09-18T04:03:19Z During the Itkillik Glaciation the Brooks Range supported an extensive mountain-glacier complex that extended for 750 km between 141° and 158°W longitude. Individual ice streams and piedmont lobes flowed as much as 50 km beyond the north and south margins of the range. Glaciers in the southern Brooks Range were longer than those farther north because of a southerly precipitation source, whereas those in the central and eastern part of the range were larger than glaciers at the extremities of the mountain system because of higher and more-extensive accumulation areas. Glacier equilibrium-line altitudes (ELAs) at the time of greatest advance were depressed 600 ± 100 m below present levels, whereas during a less-extensive late-glacial readvance (Alapah Mountain) ELA depression was about 300 ± 30 m. Radiocarbon dates indicate that Itkillik drift correlates with Late Wisconsin drift along the southern margin of the Laurentide Ice Sheet and with drift of Cordilleran glaciers in southern Alaska and the western conterminous United States deposited during the last glaciation. Itkillik I moraines represent the maximum ice advance under cold full-glacial conditions between about 24,000 and 17,000 14 C y. a. Itkillik II sediments, probably deposited close to 14,000 y. a., are characterized by abundant outwash and ice-contact stratified drift implying a milder climate than that of the Itkillik I phase. Alapah Mountain moraines at the heads of valleys draining high-altitude (≥1800 m) source areas record a possible late Itkillik readvance that is not yet closely dated. Itkillik glaciers may have largely disappeared from Brooks Range valleys by the beginning of the Holocene. Article in Journal/Newspaper Brooks Range glacier glaciers Ice Sheet Alaska Cambridge University Press Ela ENVELOPE(9.642,9.642,63.170,63.170) Quaternary Research 5 4 471 497 |
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Cambridge University Press |
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English |
description |
During the Itkillik Glaciation the Brooks Range supported an extensive mountain-glacier complex that extended for 750 km between 141° and 158°W longitude. Individual ice streams and piedmont lobes flowed as much as 50 km beyond the north and south margins of the range. Glaciers in the southern Brooks Range were longer than those farther north because of a southerly precipitation source, whereas those in the central and eastern part of the range were larger than glaciers at the extremities of the mountain system because of higher and more-extensive accumulation areas. Glacier equilibrium-line altitudes (ELAs) at the time of greatest advance were depressed 600 ± 100 m below present levels, whereas during a less-extensive late-glacial readvance (Alapah Mountain) ELA depression was about 300 ± 30 m. Radiocarbon dates indicate that Itkillik drift correlates with Late Wisconsin drift along the southern margin of the Laurentide Ice Sheet and with drift of Cordilleran glaciers in southern Alaska and the western conterminous United States deposited during the last glaciation. Itkillik I moraines represent the maximum ice advance under cold full-glacial conditions between about 24,000 and 17,000 14 C y. a. Itkillik II sediments, probably deposited close to 14,000 y. a., are characterized by abundant outwash and ice-contact stratified drift implying a milder climate than that of the Itkillik I phase. Alapah Mountain moraines at the heads of valleys draining high-altitude (≥1800 m) source areas record a possible late Itkillik readvance that is not yet closely dated. Itkillik glaciers may have largely disappeared from Brooks Range valleys by the beginning of the Holocene. |
format |
Article in Journal/Newspaper |
author |
Hamilton, Thomas D. Porter, Stephen C. |
spellingShingle |
Hamilton, Thomas D. Porter, Stephen C. Itkillik Glaciation in the Brooks Range, Northern Alaska |
author_facet |
Hamilton, Thomas D. Porter, Stephen C. |
author_sort |
Hamilton, Thomas D. |
title |
Itkillik Glaciation in the Brooks Range, Northern Alaska |
title_short |
Itkillik Glaciation in the Brooks Range, Northern Alaska |
title_full |
Itkillik Glaciation in the Brooks Range, Northern Alaska |
title_fullStr |
Itkillik Glaciation in the Brooks Range, Northern Alaska |
title_full_unstemmed |
Itkillik Glaciation in the Brooks Range, Northern Alaska |
title_sort |
itkillik glaciation in the brooks range, northern alaska |
publisher |
Cambridge University Press (CUP) |
publishDate |
1975 |
url |
http://dx.doi.org/10.1016/0033-5894(75)90012-5 http://api.elsevier.com/content/article/PII:0033589475900125?httpAccept=text/xml http://api.elsevier.com/content/article/PII:0033589475900125?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400031616 |
long_lat |
ENVELOPE(9.642,9.642,63.170,63.170) |
geographic |
Ela |
geographic_facet |
Ela |
genre |
Brooks Range glacier glaciers Ice Sheet Alaska |
genre_facet |
Brooks Range glacier glaciers Ice Sheet Alaska |
op_source |
Quaternary Research volume 5, issue 4, page 471-497 ISSN 0033-5894 1096-0287 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1016/0033-5894(75)90012-5 |
container_title |
Quaternary Research |
container_volume |
5 |
container_issue |
4 |
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471 |
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497 |
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1812812612608458752 |