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Geomorphology and sedimentology of surging glaciers: a land-systems approach
- Source :
- Annals of Glaciology. 28:75-82
- Publication Year :
- 1999
- Publisher :
- International Glaciological Society, 1999.
-
Abstract
- The identification of surging glaciers and ice streams in glaciated landscapes is of major importance to the understanding of ice-sheet dynamics and for reconstructing ice sheets and climate. No single landform or diagnostic criterion has yet been found with which to identify surging glaciers. A surging-glacier land-system model is constructed using observations and measurements from contemporary surging-glacier snouts in Iceland, Svalbard, U.S.A. and Canada for differentiating ancient surging margins from other non-surging palaeoglaciers. This integrates the suite of landforms, sediments and stratigraphy produced at surging-glacier margins. Landforms produced during surging include thrust moraines, concertina eskers and subglacial crevasse-squeeze ridges. Sedimentary sequences are usually characterized by multiple stacked diamictons and stratified interbeds, which display severe glaciotectonic contortion and faulting. Hummocky moraine, comprising interbedded stratified sediments and mass-flow diamictons, has also been associated with surge margins where large quantities of supraglacial and englacial debris entrained during the surge event have melted out in situ. An example of the application of the land-system model is presented for east-central Alberta, Canada. A surging palaeo-ice stream is identified within this part of the southwestern Laurentide ice sheet, where thrust-block moraines, crevasse-squeeze ridges, flutings, hummocky moraine and glaciotectonized sediments are juxtaposed.
- Subjects :
- 010506 paleontology
geography
geography.geographical_feature_category
010504 meteorology & atmospheric sciences
Landform
Glacier
01 natural sciences
Glaciology
Moraine
Sedimentary rock
Sedimentology
Surge
Ice sheet
Geomorphology
Geology
0105 earth and related environmental sciences
Earth-Surface Processes
Subjects
Details
- ISSN :
- 17275644 and 02603055
- Volume :
- 28
- Database :
- OpenAIRE
- Journal :
- Annals of Glaciology
- Accession number :
- edsair.doi...........6873fcecd61b7f9fd2d4b76a9e00538e