Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls
© 2018 Elsevier B.V. Tephrochronology is increasingly being utilised as a key tool for improving chronological models and correlating disparate palaeoclimatic sequences. For many sedimentary environments, however, there is an increased recognition that a range of processes may impart a delay in depo...
Published in: | Marine Geology |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://qmro.qmul.ac.uk/xmlui/handle/123456789/55004 https://doi.org/10.1016/j.margeo.2018.04.008 |
id |
ftqueenmaryuniv:oai:qmro.qmul.ac.uk:123456789/55004 |
---|---|
record_format |
openpolar |
spelling |
ftqueenmaryuniv:oai:qmro.qmul.ac.uk:123456789/55004 2023-05-15T16:48:43+02:00 Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls Abbott, PM Griggs, AJ BOURNE, AJ Davies, SM 2018-07-01 81 - 97 https://qmro.qmul.ac.uk/xmlui/handle/123456789/55004 https://doi.org/10.1016/j.margeo.2018.04.008 en eng Marine Geology 0025-3227 https://qmro.qmul.ac.uk/xmlui/handle/123456789/55004 doi:10.1016/j.margeo.2018.04.008 © 2018 Elsevier B.V. All rights reserved. Article 2018 ftqueenmaryuniv https://doi.org/10.1016/j.margeo.2018.04.008 2022-09-25T20:18:03Z © 2018 Elsevier B.V. Tephrochronology is increasingly being utilised as a key tool for improving chronological models and correlating disparate palaeoclimatic sequences. For many sedimentary environments, however, there is an increased recognition that a range of processes may impart a delay in deposition and/or rework tephra. These processes can affect the integrity of tephra deposits as time-synchronous markers, therefore, it is crucial to assess their isochronous nature, especially when cryptotephras are investigated in a dynamic marine environment. A methodology for the identification and characterisation of marine cryptotephras alongside a protocol for assessing their integrity is outlined. This methodology was applied to a wide network of North Atlantic marine sequences covering the last glacial period. A diverse range of cryptotephra deposits were identified and, based on similarities in physical characteristics (e.g. glass shard concentration profiles and geochemical homogeneity/heterogeneity), indicative of common modes of tephra delivery and post-depositional reworking, a deposit type classification scheme was defined. The presence and dominance of different deposit types within each core allowed an assessment of spatial and temporal controls on tephra deposition and preservation. Overall, isochronous horizons can be identified across a large portion of the North Atlantic due to preferential atmospheric dispersal patterns. However, the variable influence of ice-rafting processes and an interplay between the high eruptive frequency of Iceland and relatively lower sedimentation rates can also create complex tephrostratigraphies in this sector. Sites within a wide sector to the south and east of Iceland have the greatest potential to be repositories for isochronous horizons that can facilitate the synchronisation of palaeoclimatic records. Article in Journal/Newspaper Iceland North Atlantic Queen Mary University of London: Queen Mary Research Online (QMRO) Marine Geology 401 81 97 |
institution |
Open Polar |
collection |
Queen Mary University of London: Queen Mary Research Online (QMRO) |
op_collection_id |
ftqueenmaryuniv |
language |
English |
description |
© 2018 Elsevier B.V. Tephrochronology is increasingly being utilised as a key tool for improving chronological models and correlating disparate palaeoclimatic sequences. For many sedimentary environments, however, there is an increased recognition that a range of processes may impart a delay in deposition and/or rework tephra. These processes can affect the integrity of tephra deposits as time-synchronous markers, therefore, it is crucial to assess their isochronous nature, especially when cryptotephras are investigated in a dynamic marine environment. A methodology for the identification and characterisation of marine cryptotephras alongside a protocol for assessing their integrity is outlined. This methodology was applied to a wide network of North Atlantic marine sequences covering the last glacial period. A diverse range of cryptotephra deposits were identified and, based on similarities in physical characteristics (e.g. glass shard concentration profiles and geochemical homogeneity/heterogeneity), indicative of common modes of tephra delivery and post-depositional reworking, a deposit type classification scheme was defined. The presence and dominance of different deposit types within each core allowed an assessment of spatial and temporal controls on tephra deposition and preservation. Overall, isochronous horizons can be identified across a large portion of the North Atlantic due to preferential atmospheric dispersal patterns. However, the variable influence of ice-rafting processes and an interplay between the high eruptive frequency of Iceland and relatively lower sedimentation rates can also create complex tephrostratigraphies in this sector. Sites within a wide sector to the south and east of Iceland have the greatest potential to be repositories for isochronous horizons that can facilitate the synchronisation of palaeoclimatic records. |
format |
Article in Journal/Newspaper |
author |
Abbott, PM Griggs, AJ BOURNE, AJ Davies, SM |
spellingShingle |
Abbott, PM Griggs, AJ BOURNE, AJ Davies, SM Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls |
author_facet |
Abbott, PM Griggs, AJ BOURNE, AJ Davies, SM |
author_sort |
Abbott, PM |
title |
Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls |
title_short |
Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls |
title_full |
Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls |
title_fullStr |
Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls |
title_full_unstemmed |
Tracing marine cryptotephras in the North Atlantic during the last glacial period: Protocols for identification, characterisation and evaluating depositional controls |
title_sort |
tracing marine cryptotephras in the north atlantic during the last glacial period: protocols for identification, characterisation and evaluating depositional controls |
publishDate |
2018 |
url |
https://qmro.qmul.ac.uk/xmlui/handle/123456789/55004 https://doi.org/10.1016/j.margeo.2018.04.008 |
genre |
Iceland North Atlantic |
genre_facet |
Iceland North Atlantic |
op_relation |
Marine Geology 0025-3227 https://qmro.qmul.ac.uk/xmlui/handle/123456789/55004 doi:10.1016/j.margeo.2018.04.008 |
op_rights |
© 2018 Elsevier B.V. All rights reserved. |
op_doi |
https://doi.org/10.1016/j.margeo.2018.04.008 |
container_title |
Marine Geology |
container_volume |
401 |
container_start_page |
81 |
op_container_end_page |
97 |
_version_ |
1766038792736604160 |