The age and chronostratigraphical significance of North Atlantic Ash Zone II
Rhyolitic tephra with the geochemical characteristics of North Atlantic Ash Zone (NAAZ) II are described from the giant piston core MD95-2006 from the northeast Atlantic Ocean. Shard size distribution indicates that the tephra represent a wind-sorted, primary air-fall deposit, but with a mode close...
Published in: | Journal of Quaternary Science |
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Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2004
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Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/the-age-and-chronostratigraphical-significance-of-north-atlantic-ash-zone-ii(2f0d8872-1928-467a-93e8-1ee5417359ca).html https://doi.org/10.1002/jqs.821 http://www.scopus.com/inward/record.url?scp=15044350000&partnerID=8YFLogxK |
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/2f0d8872-1928-467a-93e8-1ee5417359ca 2023-05-15T16:28:39+02:00 The age and chronostratigraphical significance of North Atlantic Ash Zone II Austin, W E N Wilson, L J Hunt, J B 2004-02 https://risweb.st-andrews.ac.uk/portal/en/researchoutput/the-age-and-chronostratigraphical-significance-of-north-atlantic-ash-zone-ii(2f0d8872-1928-467a-93e8-1ee5417359ca).html https://doi.org/10.1002/jqs.821 http://www.scopus.com/inward/record.url?scp=15044350000&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Austin , W E N , Wilson , L J & Hunt , J B 2004 , ' The age and chronostratigraphical significance of North Atlantic Ash Zone II ' , Journal of Quaternary Science , vol. 19 , no. 2 , pp. 137-146 . https://doi.org/10.1002/jqs.821 tephra radiocarbon dating Dansgaard-Oeschger cycle ice cores North Atlantic Ocean ELECTRON-PROBE MICROANALYSIS GREENLAND ICE-CORE VOLCANIC ASH LATE QUATERNARY LATE PLEISTOCENE ICELAND HOTSPOT C-14 AGES SEDIMENTS CLIMATE CALIBRATION article 2004 ftunstandrewcris https://doi.org/10.1002/jqs.821 2021-12-26T14:16:40Z Rhyolitic tephra with the geochemical characteristics of North Atlantic Ash Zone (NAAZ) II are described from the giant piston core MD95-2006 from the northeast Atlantic Ocean. Shard size distribution indicates that the tephra represent a wind-sorted, primary air-fall deposit, but with a mode close to 200 mum they are too coarse to be air-fall deposits at the core site, which lies ca. 1000 km from the possible tephra source. Randomly sampled shards reveal a single geochemical population belonging to the Icelandic transitional alkali magma series, Suggesting that they are unlikely to represent ice rafted debris derived from Icelandic icebergs. The tephra probably represent airfall deposits, transported to the core site by sea ice within the northeast Atlantic gyre. The NAAZ II peak coincides with the rapid climate transition (cooling) at the end of interstadial 15, which can be assigned an age of 53 260 +/- 2660 yr BP from direct correlation with the Greenland ice-core (GISP2) record. A comparison of the MD95-2006 Neogloboquadrina pachyderma (sinistral) relative abundance and GISP2 delta(18)O records, relative to the NAAZ II isochron, suggests that this climatic event was synchronous across the North Atlantic. By direct correlation of interstadial maxima between the two records, the GISP2 time-scale is transferred to MD95-2006. Comparison of corrected and calibrated radiocarbon ages derived from monospecific foraminifers with the GISP2 ages at the same stratigraphical horizon suggest major age differences. These probably result from large variations in atmospheric C-14 Concentration and highlight the significant uncertainties associated with radiocarbon calibration during marine isotope stage 3. Copyright (C) 2004 John Wiley Sons, Ltd. Article in Journal/Newspaper Greenland Greenland ice core ice core Iceland Neogloboquadrina pachyderma North Atlantic Northeast Atlantic Sea ice University of St Andrews: Research Portal Greenland Journal of Quaternary Science 19 2 137 146 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
tephra radiocarbon dating Dansgaard-Oeschger cycle ice cores North Atlantic Ocean ELECTRON-PROBE MICROANALYSIS GREENLAND ICE-CORE VOLCANIC ASH LATE QUATERNARY LATE PLEISTOCENE ICELAND HOTSPOT C-14 AGES SEDIMENTS CLIMATE CALIBRATION |
spellingShingle |
tephra radiocarbon dating Dansgaard-Oeschger cycle ice cores North Atlantic Ocean ELECTRON-PROBE MICROANALYSIS GREENLAND ICE-CORE VOLCANIC ASH LATE QUATERNARY LATE PLEISTOCENE ICELAND HOTSPOT C-14 AGES SEDIMENTS CLIMATE CALIBRATION Austin, W E N Wilson, L J Hunt, J B The age and chronostratigraphical significance of North Atlantic Ash Zone II |
topic_facet |
tephra radiocarbon dating Dansgaard-Oeschger cycle ice cores North Atlantic Ocean ELECTRON-PROBE MICROANALYSIS GREENLAND ICE-CORE VOLCANIC ASH LATE QUATERNARY LATE PLEISTOCENE ICELAND HOTSPOT C-14 AGES SEDIMENTS CLIMATE CALIBRATION |
description |
Rhyolitic tephra with the geochemical characteristics of North Atlantic Ash Zone (NAAZ) II are described from the giant piston core MD95-2006 from the northeast Atlantic Ocean. Shard size distribution indicates that the tephra represent a wind-sorted, primary air-fall deposit, but with a mode close to 200 mum they are too coarse to be air-fall deposits at the core site, which lies ca. 1000 km from the possible tephra source. Randomly sampled shards reveal a single geochemical population belonging to the Icelandic transitional alkali magma series, Suggesting that they are unlikely to represent ice rafted debris derived from Icelandic icebergs. The tephra probably represent airfall deposits, transported to the core site by sea ice within the northeast Atlantic gyre. The NAAZ II peak coincides with the rapid climate transition (cooling) at the end of interstadial 15, which can be assigned an age of 53 260 +/- 2660 yr BP from direct correlation with the Greenland ice-core (GISP2) record. A comparison of the MD95-2006 Neogloboquadrina pachyderma (sinistral) relative abundance and GISP2 delta(18)O records, relative to the NAAZ II isochron, suggests that this climatic event was synchronous across the North Atlantic. By direct correlation of interstadial maxima between the two records, the GISP2 time-scale is transferred to MD95-2006. Comparison of corrected and calibrated radiocarbon ages derived from monospecific foraminifers with the GISP2 ages at the same stratigraphical horizon suggest major age differences. These probably result from large variations in atmospheric C-14 Concentration and highlight the significant uncertainties associated with radiocarbon calibration during marine isotope stage 3. Copyright (C) 2004 John Wiley Sons, Ltd. |
format |
Article in Journal/Newspaper |
author |
Austin, W E N Wilson, L J Hunt, J B |
author_facet |
Austin, W E N Wilson, L J Hunt, J B |
author_sort |
Austin, W E N |
title |
The age and chronostratigraphical significance of North Atlantic Ash Zone II |
title_short |
The age and chronostratigraphical significance of North Atlantic Ash Zone II |
title_full |
The age and chronostratigraphical significance of North Atlantic Ash Zone II |
title_fullStr |
The age and chronostratigraphical significance of North Atlantic Ash Zone II |
title_full_unstemmed |
The age and chronostratigraphical significance of North Atlantic Ash Zone II |
title_sort |
age and chronostratigraphical significance of north atlantic ash zone ii |
publishDate |
2004 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/the-age-and-chronostratigraphical-significance-of-north-atlantic-ash-zone-ii(2f0d8872-1928-467a-93e8-1ee5417359ca).html https://doi.org/10.1002/jqs.821 http://www.scopus.com/inward/record.url?scp=15044350000&partnerID=8YFLogxK |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Greenland ice core ice core Iceland Neogloboquadrina pachyderma North Atlantic Northeast Atlantic Sea ice |
genre_facet |
Greenland Greenland ice core ice core Iceland Neogloboquadrina pachyderma North Atlantic Northeast Atlantic Sea ice |
op_source |
Austin , W E N , Wilson , L J & Hunt , J B 2004 , ' The age and chronostratigraphical significance of North Atlantic Ash Zone II ' , Journal of Quaternary Science , vol. 19 , no. 2 , pp. 137-146 . https://doi.org/10.1002/jqs.821 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1002/jqs.821 |
container_title |
Journal of Quaternary Science |
container_volume |
19 |
container_issue |
2 |
container_start_page |
137 |
op_container_end_page |
146 |
_version_ |
1766018322606850048 |