Fabric signature of subglacial till deformation, Breidamerkurjökull, Iceland
ABSTRACT The foreland of Breidamerkurjökull, Iceland, is the only locality where tills known to have undergone subglacial deformation are exposed. Till on the foreland has a two‐tiered structure, consisting of a dilatant upper horizon c 0.5 m thick and a compact lower till; these horizons correspond...
Published in: | Sedimentology |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
1995
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1111/j.1365-3091.1995.tb00406.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3091.1995.tb00406.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3091.1995.tb00406.x |
id |
crwiley:10.1111/j.1365-3091.1995.tb00406.x |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1111/j.1365-3091.1995.tb00406.x 2024-09-30T14:35:24+00:00 Fabric signature of subglacial till deformation, Breidamerkurjökull, Iceland BENN, DOUGLAS I. 1995 http://dx.doi.org/10.1111/j.1365-3091.1995.tb00406.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3091.1995.tb00406.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3091.1995.tb00406.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Sedimentology volume 42, issue 5, page 735-747 ISSN 0037-0746 1365-3091 journal-article 1995 crwiley https://doi.org/10.1111/j.1365-3091.1995.tb00406.x 2024-09-17T04:45:11Z ABSTRACT The foreland of Breidamerkurjökull, Iceland, is the only locality where tills known to have undergone subglacial deformation are exposed. Till on the foreland has a two‐tiered structure, consisting of a dilatant upper horizon c 0.5 m thick and a compact lower till; these horizons correspond to the ductile deforming A horizon and the brittle‐ductile B horizon observed below the glacier by G. S. Boulton and co‐workers. The relationship between known strain history and a variety of macrofabric elements is examined for these two genetic facies of deformation till. The upper horizon exhibits variable a ‐axis fabrics and abundant evidence for clast re‐alignment, reflecting ductile flow and rapid clast response to transient strains. In contrast, the lower horizon has consistently well organized a ‐axis fabrics with a narrow range of dip values, recording clast rotation into parallel with strain axes during brittle or brittle‐ductile shear. The data indicate that till strain history imparts identifiable macrofabric signatures, providing important analogues to guide the interpretation of Pleistocene tills. Article in Journal/Newspaper glacier Iceland Wiley Online Library Sedimentology 42 5 735 747 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
ABSTRACT The foreland of Breidamerkurjökull, Iceland, is the only locality where tills known to have undergone subglacial deformation are exposed. Till on the foreland has a two‐tiered structure, consisting of a dilatant upper horizon c 0.5 m thick and a compact lower till; these horizons correspond to the ductile deforming A horizon and the brittle‐ductile B horizon observed below the glacier by G. S. Boulton and co‐workers. The relationship between known strain history and a variety of macrofabric elements is examined for these two genetic facies of deformation till. The upper horizon exhibits variable a ‐axis fabrics and abundant evidence for clast re‐alignment, reflecting ductile flow and rapid clast response to transient strains. In contrast, the lower horizon has consistently well organized a ‐axis fabrics with a narrow range of dip values, recording clast rotation into parallel with strain axes during brittle or brittle‐ductile shear. The data indicate that till strain history imparts identifiable macrofabric signatures, providing important analogues to guide the interpretation of Pleistocene tills. |
format |
Article in Journal/Newspaper |
author |
BENN, DOUGLAS I. |
spellingShingle |
BENN, DOUGLAS I. Fabric signature of subglacial till deformation, Breidamerkurjökull, Iceland |
author_facet |
BENN, DOUGLAS I. |
author_sort |
BENN, DOUGLAS I. |
title |
Fabric signature of subglacial till deformation, Breidamerkurjökull, Iceland |
title_short |
Fabric signature of subglacial till deformation, Breidamerkurjökull, Iceland |
title_full |
Fabric signature of subglacial till deformation, Breidamerkurjökull, Iceland |
title_fullStr |
Fabric signature of subglacial till deformation, Breidamerkurjökull, Iceland |
title_full_unstemmed |
Fabric signature of subglacial till deformation, Breidamerkurjökull, Iceland |
title_sort |
fabric signature of subglacial till deformation, breidamerkurjökull, iceland |
publisher |
Wiley |
publishDate |
1995 |
url |
http://dx.doi.org/10.1111/j.1365-3091.1995.tb00406.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-3091.1995.tb00406.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3091.1995.tb00406.x |
genre |
glacier Iceland |
genre_facet |
glacier Iceland |
op_source |
Sedimentology volume 42, issue 5, page 735-747 ISSN 0037-0746 1365-3091 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1365-3091.1995.tb00406.x |
container_title |
Sedimentology |
container_volume |
42 |
container_issue |
5 |
container_start_page |
735 |
op_container_end_page |
747 |
_version_ |
1811638688326615040 |