Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas
We present a new speleothem record of atmospheric Delta C-14 between 28 and 44 ka that offers considerable promise for resolving some of the uncertainty associated with existing radiocarbon calibration curves for this time period. The record is based on a comprehensive suite of AMS C-14 ages, using...
Published in: | Earth and Planetary Science Letters |
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Main Authors: | , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2010
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Online Access: | https://research-portal.st-andrews.ac.uk/en/researchoutput/towards-radiocarbon-calibration-beyond-28-ka-using-speleothems-from-the-bahamas(724295c2-0fba-4807-bfa6-f49bd1d9ba07).html https://doi.org/10.1016/j.epsl.2009.10.004 http://www.scopus.com/inward/record.url?scp=73049088350&partnerID=8YFLogxK |
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ftunstandrewcris:oai:research-portal.st-andrews.ac.uk:publications/724295c2-0fba-4807-bfa6-f49bd1d9ba07 2024-06-23T07:53:25+00:00 Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas Hoffmann, Dirk L. Beck, J. Warren Richards, David A. Smart, Peter L. Singarayer, Joy S. Ketchmark, Tricia Hawkesworth, Chris J. 2010-01-15 https://research-portal.st-andrews.ac.uk/en/researchoutput/towards-radiocarbon-calibration-beyond-28-ka-using-speleothems-from-the-bahamas(724295c2-0fba-4807-bfa6-f49bd1d9ba07).html https://doi.org/10.1016/j.epsl.2009.10.004 http://www.scopus.com/inward/record.url?scp=73049088350&partnerID=8YFLogxK eng eng https://research-portal.st-andrews.ac.uk/en/researchoutput/towards-radiocarbon-calibration-beyond-28-ka-using-speleothems-from-the-bahamas(724295c2-0fba-4807-bfa6-f49bd1d9ba07).html info:eu-repo/semantics/restrictedAccess Hoffmann , D L , Beck , J W , Richards , D A , Smart , P L , Singarayer , J S , Ketchmark , T & Hawkesworth , C J 2010 , ' Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas ' , Earth and Planetary Science Letters , vol. 289 , no. 1-2 , pp. 110 . https://doi.org/10.1016/j.epsl.2009.10.004 radiocarbon U-Th dating speleothems MIS 3 geomagnetic intensity earth system models LAST GLACIAL PERIOD EARTH SYSTEM MODEL PAST 50,000 YEARS CURVE SPANNING 0 PAPUA-NEW-GUINEA CAL KYR BP C-14 CALIBRATION AGE CALIBRATION HALF-LIVES PAIRED TH-230/U-234/U-238 article 2010 ftunstandrewcris https://doi.org/10.1016/j.epsl.2009.10.004 2024-06-13T00:26:44Z We present a new speleothem record of atmospheric Delta C-14 between 28 and 44 ka that offers considerable promise for resolving some of the uncertainty associated with existing radiocarbon calibration curves for this time period. The record is based on a comprehensive suite of AMS C-14 ages, using new low-blank protocols, and U-Th ages using high precision MC-ICPMS procedures. Atmospheric Delta C-14 was calculated by correcting C-14 ages with a constant dead carbon fraction (DCF) of 22.7 +/- 5.9%, based on a comparison of stalagmite C-14 ages with the lntCal04 (Reimer et al., 2004) calibration curve between 15 and 11 ka. The new Delta C-14 speleothem record shows similar structure and amplitude to that derived from Cariaco Basin foraminifera (Hughen et al., 2004, 2006), and the match is further improved if the latter is tied to the most recent Greenland ice core chronology (Svensson et al., 2008). These data are however in conflict with a previously published C-14 data set for a stalagmite record from the Bahamas - CB-89-24-1 (Beck et al., 2001), which likely suffered from C-14 analytical blank subtraction issues in the older part of the record. The new Bahamas speleothem. Delta C-14 data do not show the extreme shifts between 44 and 40 ka reported in the previous study (Beck et al., 2001). Causes for the observed structure in derived atmospheric Delta C-14 variation based on the new speleothem data are investigated with a suite of simulations using an earth system model of intermediate complexity. Data-model comparison indicates that major fluctuations in atmospheric Delta C-14 during marine isotope stage 3 is primarily a function of changes in geomagnetic field intensity, although ocean-atmosphere system reorganisation also played a supporting role. (C) 2009 Elsevier B.V. All rights reserved. Article in Journal/Newspaper Greenland Greenland ice core ice core University of St Andrews: Research Portal Beck ENVELOPE(67.017,67.017,-71.033,-71.033) Greenland Reimer ENVELOPE(-86.200,-86.200,-77.800,-77.800) Earth and Planetary Science Letters 289 1-2 1 10 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
radiocarbon U-Th dating speleothems MIS 3 geomagnetic intensity earth system models LAST GLACIAL PERIOD EARTH SYSTEM MODEL PAST 50,000 YEARS CURVE SPANNING 0 PAPUA-NEW-GUINEA CAL KYR BP C-14 CALIBRATION AGE CALIBRATION HALF-LIVES PAIRED TH-230/U-234/U-238 |
spellingShingle |
radiocarbon U-Th dating speleothems MIS 3 geomagnetic intensity earth system models LAST GLACIAL PERIOD EARTH SYSTEM MODEL PAST 50,000 YEARS CURVE SPANNING 0 PAPUA-NEW-GUINEA CAL KYR BP C-14 CALIBRATION AGE CALIBRATION HALF-LIVES PAIRED TH-230/U-234/U-238 Hoffmann, Dirk L. Beck, J. Warren Richards, David A. Smart, Peter L. Singarayer, Joy S. Ketchmark, Tricia Hawkesworth, Chris J. Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas |
topic_facet |
radiocarbon U-Th dating speleothems MIS 3 geomagnetic intensity earth system models LAST GLACIAL PERIOD EARTH SYSTEM MODEL PAST 50,000 YEARS CURVE SPANNING 0 PAPUA-NEW-GUINEA CAL KYR BP C-14 CALIBRATION AGE CALIBRATION HALF-LIVES PAIRED TH-230/U-234/U-238 |
description |
We present a new speleothem record of atmospheric Delta C-14 between 28 and 44 ka that offers considerable promise for resolving some of the uncertainty associated with existing radiocarbon calibration curves for this time period. The record is based on a comprehensive suite of AMS C-14 ages, using new low-blank protocols, and U-Th ages using high precision MC-ICPMS procedures. Atmospheric Delta C-14 was calculated by correcting C-14 ages with a constant dead carbon fraction (DCF) of 22.7 +/- 5.9%, based on a comparison of stalagmite C-14 ages with the lntCal04 (Reimer et al., 2004) calibration curve between 15 and 11 ka. The new Delta C-14 speleothem record shows similar structure and amplitude to that derived from Cariaco Basin foraminifera (Hughen et al., 2004, 2006), and the match is further improved if the latter is tied to the most recent Greenland ice core chronology (Svensson et al., 2008). These data are however in conflict with a previously published C-14 data set for a stalagmite record from the Bahamas - CB-89-24-1 (Beck et al., 2001), which likely suffered from C-14 analytical blank subtraction issues in the older part of the record. The new Bahamas speleothem. Delta C-14 data do not show the extreme shifts between 44 and 40 ka reported in the previous study (Beck et al., 2001). Causes for the observed structure in derived atmospheric Delta C-14 variation based on the new speleothem data are investigated with a suite of simulations using an earth system model of intermediate complexity. Data-model comparison indicates that major fluctuations in atmospheric Delta C-14 during marine isotope stage 3 is primarily a function of changes in geomagnetic field intensity, although ocean-atmosphere system reorganisation also played a supporting role. (C) 2009 Elsevier B.V. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Hoffmann, Dirk L. Beck, J. Warren Richards, David A. Smart, Peter L. Singarayer, Joy S. Ketchmark, Tricia Hawkesworth, Chris J. |
author_facet |
Hoffmann, Dirk L. Beck, J. Warren Richards, David A. Smart, Peter L. Singarayer, Joy S. Ketchmark, Tricia Hawkesworth, Chris J. |
author_sort |
Hoffmann, Dirk L. |
title |
Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas |
title_short |
Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas |
title_full |
Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas |
title_fullStr |
Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas |
title_full_unstemmed |
Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas |
title_sort |
towards radiocarbon calibration beyond 28 ka using speleothems from the bahamas |
publishDate |
2010 |
url |
https://research-portal.st-andrews.ac.uk/en/researchoutput/towards-radiocarbon-calibration-beyond-28-ka-using-speleothems-from-the-bahamas(724295c2-0fba-4807-bfa6-f49bd1d9ba07).html https://doi.org/10.1016/j.epsl.2009.10.004 http://www.scopus.com/inward/record.url?scp=73049088350&partnerID=8YFLogxK |
long_lat |
ENVELOPE(67.017,67.017,-71.033,-71.033) ENVELOPE(-86.200,-86.200,-77.800,-77.800) |
geographic |
Beck Greenland Reimer |
geographic_facet |
Beck Greenland Reimer |
genre |
Greenland Greenland ice core ice core |
genre_facet |
Greenland Greenland ice core ice core |
op_source |
Hoffmann , D L , Beck , J W , Richards , D A , Smart , P L , Singarayer , J S , Ketchmark , T & Hawkesworth , C J 2010 , ' Towards radiocarbon calibration beyond 28 ka using speleothems from the Bahamas ' , Earth and Planetary Science Letters , vol. 289 , no. 1-2 , pp. 110 . https://doi.org/10.1016/j.epsl.2009.10.004 |
op_relation |
https://research-portal.st-andrews.ac.uk/en/researchoutput/towards-radiocarbon-calibration-beyond-28-ka-using-speleothems-from-the-bahamas(724295c2-0fba-4807-bfa6-f49bd1d9ba07).html |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2009.10.004 |
container_title |
Earth and Planetary Science Letters |
container_volume |
289 |
container_issue |
1-2 |
container_start_page |
1 |
op_container_end_page |
10 |
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1802645050828521472 |