Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska
The study of glacial landforms and deposits is important, as it isdifficult to observe processes under modern glaciers and ice-sheets. Thus landscapes and sediments that are the product of present glaciation can give insight into processes that occurred during Pleistocene times. This study investiga...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
CEG
2009-06-01
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| Series: | Finisterra - Revista Portuguesa de Geografia |
| Subjects: | |
| Online Access: | http://www.ceg.ul.pt/finisterra/numeros/2009-87/87_08.pdf |
| _version_ | 1818575031804887040 |
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| author | Carlos Córdova João Santos |
| author_facet | Carlos Córdova João Santos |
| author_sort | Carlos Córdova |
| collection | DOAJ |
| description | The study of glacial landforms and deposits is important, as it isdifficult to observe processes under modern glaciers and ice-sheets. Thus landscapes and sediments that are the product of present glaciation can give insight into processes that occurred during Pleistocene times. This study investigates the genesis of little ice age glacial landforms present in Portage Glacier, South-Central Alaska. The present day moraine morphology and sedimentology in Portage Glacier valley reveals the presence of two types of till and moraines. The clast-rich sandy diamicton present on the 1852 moraine is interpreted to be a basal till indicating this feature is a pushmoraine representing an advance or a standstill position of Portage Glacier in 1852. The moderately sorted gray sandy boulder gravel present on the 1900 and 1922 moraines is interpreted to be an ice-marginal deposit (ablation till) with a mixture of supraglacial and glaciofluvial sediments deposited by slumping and stream sortingprocesses. All of these features are interpreted to be ablation moraines representing glacier retreat and moraine building in 1900 and1922. |
| first_indexed | 2024-12-15T00:34:50Z |
| format | Article |
| id | doaj.art-184a0c16fb4e4a0bbaaf6aaac14631b4 |
| institution | Directory Open Access Journal |
| issn | 0430-5027 |
| language | English |
| last_indexed | 2024-12-15T00:34:50Z |
| publishDate | 2009-06-01 |
| publisher | CEG |
| record_format | Article |
| series | Finisterra - Revista Portuguesa de Geografia |
| spelling | doaj.art-184a0c16fb4e4a0bbaaf6aaac14631b42022-12-21T22:41:50ZengCEGFinisterra - Revista Portuguesa de Geografia0430-50272009-06-01XLIV8795108Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central AlaskaCarlos CórdovaJoão SantosThe study of glacial landforms and deposits is important, as it isdifficult to observe processes under modern glaciers and ice-sheets. Thus landscapes and sediments that are the product of present glaciation can give insight into processes that occurred during Pleistocene times. This study investigates the genesis of little ice age glacial landforms present in Portage Glacier, South-Central Alaska. The present day moraine morphology and sedimentology in Portage Glacier valley reveals the presence of two types of till and moraines. The clast-rich sandy diamicton present on the 1852 moraine is interpreted to be a basal till indicating this feature is a pushmoraine representing an advance or a standstill position of Portage Glacier in 1852. The moderately sorted gray sandy boulder gravel present on the 1900 and 1922 moraines is interpreted to be an ice-marginal deposit (ablation till) with a mixture of supraglacial and glaciofluvial sediments deposited by slumping and stream sortingprocesses. All of these features are interpreted to be ablation moraines representing glacier retreat and moraine building in 1900 and1922.http://www.ceg.ul.pt/finisterra/numeros/2009-87/87_08.pdfGlacial geomorphologyPortage GlacierSouth-Central Alaska. |
| spellingShingle | Carlos Córdova João Santos Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska Finisterra - Revista Portuguesa de Geografia Glacial geomorphology Portage Glacier South-Central Alaska. |
| title | Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska |
| title_full | Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska |
| title_fullStr | Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska |
| title_full_unstemmed | Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska |
| title_short | Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska |
| title_sort | little ice age glacial geomorphology and sedimentology of portage glacier south central alaska |
| topic | Glacial geomorphology Portage Glacier South-Central Alaska. |
| url | http://www.ceg.ul.pt/finisterra/numeros/2009-87/87_08.pdf |
| work_keys_str_mv | AT carloscordova littleiceageglacialgeomorphologyandsedimentologyofportageglaciersouthcentralalaska AT joaosantos littleiceageglacialgeomorphologyandsedimentologyofportageglaciersouthcentralalaska |