Architecture and sedimentation of outwash fans in front of the Myrdalsjokull ice cap, Iceland
In this study, we introduce the architecture and style of sedimentation of two outwash fans in front of the Myrdalsjokull ice cap, central south Iceland, that broaden different types of ice-marginal sedimentation. At Kotlujokull, a southeastern outlet of the ice cap, fan formation was monitored from...
Published in: | Sedimentary Geology |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2004
|
Subjects: | |
Online Access: | https://lup.lub.lu.se/record/259802 https://doi.org/10.1016/j.sedgeo.2004.08.002 |
id |
ftulundlup:oai:lup.lub.lu.se:cd394d84-2926-4bd8-834d-1e3349f915fa |
---|---|
record_format |
openpolar |
spelling |
ftulundlup:oai:lup.lub.lu.se:cd394d84-2926-4bd8-834d-1e3349f915fa 2023-05-15T16:38:07+02:00 Architecture and sedimentation of outwash fans in front of the Myrdalsjokull ice cap, Iceland Kjaer, Kurt Sultan, L Kruger, J Schomacker, Anders 2004 https://lup.lub.lu.se/record/259802 https://doi.org/10.1016/j.sedgeo.2004.08.002 eng eng Elsevier https://lup.lub.lu.se/record/259802 http://dx.doi.org/10.1016/j.sedgeo.2004.08.002 wos:000225346400008 scopus:7544225097 Sedimentary Geology; 172(1-2), pp 139-163 (2004) ISSN: 0037-0738 Geology sediment architecture hochsander outwash fans supraglacial Iceland Myrdalsjokull contributiontojournal/article info:eu-repo/semantics/article text 2004 ftulundlup https://doi.org/10.1016/j.sedgeo.2004.08.002 2023-02-01T23:27:22Z In this study, we introduce the architecture and style of sedimentation of two outwash fans in front of the Myrdalsjokull ice cap, central south Iceland, that broaden different types of ice-marginal sedimentation. At Kotlujokull, a southeastern outlet of the ice cap, fan formation was monitored from the late 1970s to 2002; thus, the style of sedimentation is well understood and the relationship to the depositional architecture easily established. In front of Slettjokull, a northern lobate extension of the ice cap, a fan from the 10th century AD is capped by neoglacial till sheets. At both sites, the fan surfaces were reconstructed in three dimensions. Ground Penetrating Radar (GPR) provided the thickness and internal structure of sediment bodies. Geological exposures and excavations were used for detailed sedimentological documentation of the outwash deposits in proximal-to-distal transects. The outwash deposits at both Kotlujokull and Slettjokull are considered to be alluvial fans of the hochsander type, i.e., supraglacially fed, as they show all the architectural characteristics of alluvial fans with a semiconical shape, a restricted radial length of ca. 0.5-1.5 km, a plano-convex cross-profile and a slope gradient ranging between 1 and 5. Fan deposits are dominated by planar or low-angle cross-bedded sand facies interbedded with thin laminae of fine gravel occasionally draped by mud. Sedimentation occurs during upper flow regime sheetflows associated with antidune migration within an aggrading, shallow braided-stream network. Hochsanders are intimately linked to advancing or stationary glaciers with steep ice-cored frontal slopes that favor supraglacial over subglacial drainage. Most important, hochsander fans lack any proximal-to-distal transition in the grain-size distribution, sediment facies or facies associations. Because much classification of glacial outwash sediments is based on proximal-to-distal distinctions, it is crucial to consider the depositional model for hochsanders. This study also indicates ... Article in Journal/Newspaper Ice cap Iceland Lund University Publications (LUP) Plano ENVELOPE(-61.250,-61.250,-62.783,-62.783) Sedimentary Geology 172 1-2 139 163 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology sediment architecture hochsander outwash fans supraglacial Iceland Myrdalsjokull |
spellingShingle |
Geology sediment architecture hochsander outwash fans supraglacial Iceland Myrdalsjokull Kjaer, Kurt Sultan, L Kruger, J Schomacker, Anders Architecture and sedimentation of outwash fans in front of the Myrdalsjokull ice cap, Iceland |
topic_facet |
Geology sediment architecture hochsander outwash fans supraglacial Iceland Myrdalsjokull |
description |
In this study, we introduce the architecture and style of sedimentation of two outwash fans in front of the Myrdalsjokull ice cap, central south Iceland, that broaden different types of ice-marginal sedimentation. At Kotlujokull, a southeastern outlet of the ice cap, fan formation was monitored from the late 1970s to 2002; thus, the style of sedimentation is well understood and the relationship to the depositional architecture easily established. In front of Slettjokull, a northern lobate extension of the ice cap, a fan from the 10th century AD is capped by neoglacial till sheets. At both sites, the fan surfaces were reconstructed in three dimensions. Ground Penetrating Radar (GPR) provided the thickness and internal structure of sediment bodies. Geological exposures and excavations were used for detailed sedimentological documentation of the outwash deposits in proximal-to-distal transects. The outwash deposits at both Kotlujokull and Slettjokull are considered to be alluvial fans of the hochsander type, i.e., supraglacially fed, as they show all the architectural characteristics of alluvial fans with a semiconical shape, a restricted radial length of ca. 0.5-1.5 km, a plano-convex cross-profile and a slope gradient ranging between 1 and 5. Fan deposits are dominated by planar or low-angle cross-bedded sand facies interbedded with thin laminae of fine gravel occasionally draped by mud. Sedimentation occurs during upper flow regime sheetflows associated with antidune migration within an aggrading, shallow braided-stream network. Hochsanders are intimately linked to advancing or stationary glaciers with steep ice-cored frontal slopes that favor supraglacial over subglacial drainage. Most important, hochsander fans lack any proximal-to-distal transition in the grain-size distribution, sediment facies or facies associations. Because much classification of glacial outwash sediments is based on proximal-to-distal distinctions, it is crucial to consider the depositional model for hochsanders. This study also indicates ... |
format |
Article in Journal/Newspaper |
author |
Kjaer, Kurt Sultan, L Kruger, J Schomacker, Anders |
author_facet |
Kjaer, Kurt Sultan, L Kruger, J Schomacker, Anders |
author_sort |
Kjaer, Kurt |
title |
Architecture and sedimentation of outwash fans in front of the Myrdalsjokull ice cap, Iceland |
title_short |
Architecture and sedimentation of outwash fans in front of the Myrdalsjokull ice cap, Iceland |
title_full |
Architecture and sedimentation of outwash fans in front of the Myrdalsjokull ice cap, Iceland |
title_fullStr |
Architecture and sedimentation of outwash fans in front of the Myrdalsjokull ice cap, Iceland |
title_full_unstemmed |
Architecture and sedimentation of outwash fans in front of the Myrdalsjokull ice cap, Iceland |
title_sort |
architecture and sedimentation of outwash fans in front of the myrdalsjokull ice cap, iceland |
publisher |
Elsevier |
publishDate |
2004 |
url |
https://lup.lub.lu.se/record/259802 https://doi.org/10.1016/j.sedgeo.2004.08.002 |
long_lat |
ENVELOPE(-61.250,-61.250,-62.783,-62.783) |
geographic |
Plano |
geographic_facet |
Plano |
genre |
Ice cap Iceland |
genre_facet |
Ice cap Iceland |
op_source |
Sedimentary Geology; 172(1-2), pp 139-163 (2004) ISSN: 0037-0738 |
op_relation |
https://lup.lub.lu.se/record/259802 http://dx.doi.org/10.1016/j.sedgeo.2004.08.002 wos:000225346400008 scopus:7544225097 |
op_doi |
https://doi.org/10.1016/j.sedgeo.2004.08.002 |
container_title |
Sedimentary Geology |
container_volume |
172 |
container_issue |
1-2 |
container_start_page |
139 |
op_container_end_page |
163 |
_version_ |
1766028410114539520 |