Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas
We present a new speleothem record of atmospheric Δ14C 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 14C ages, using new low...
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2010
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Online Access: | https://hdl.handle.net/1983/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 https://research-information.bris.ac.uk/en/publications/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 https://doi.org/10.1016/j.epsl.2009.10.004 http://www.sciencedirect.com/science/article/pii/S0012821X09006037 |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 2024-04-28T08:22:30+00:00 Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas Hoffmann, DL Beck, JW Richards, DA Smart, PL Singarayer, JS Ketchmark, T Hawkesworth, CJ 2010 https://hdl.handle.net/1983/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 https://research-information.bris.ac.uk/en/publications/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 https://doi.org/10.1016/j.epsl.2009.10.004 http://www.sciencedirect.com/science/article/pii/S0012821X09006037 eng eng https://research-information.bris.ac.uk/en/publications/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 info:eu-repo/semantics/restrictedAccess Hoffmann , DL , Beck , JW , Richards , DA , Smart , PL , Singarayer , JS , Ketchmark , T & Hawkesworth , CJ 2010 , ' Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas ' , Earth and Planetary Science Letters , vol. 289 , no. 1-2 , pp. 1 - 10 . https://doi.org/10.1016/j.epsl.2009.10.004 article 2010 ftubristolcris https://doi.org/10.1016/j.epsl.2009.10.004 2024-04-03T15:06:37Z We present a new speleothem record of atmospheric Δ14C 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 14C ages, using new low-blank protocols, and U–Th ages using high precision MC-ICPMS procedures. Atmospheric Δ14C was calculated by correcting 14C ages with a constant dead carbon fraction (DCF) of 22.7 ± 5.9%, based on a comparison of stalagmite 14C ages with the IntCal04 (Reimer et al., 2004) calibration curve between 15 and 11 ka. The new Δ14C 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 14C data set for a stalagmite record from the Bahamas — GB-89-24-1 (Beck et al., 2001), which likely suffered from 14C analytical blank subtraction issues in the older part of the record. The new Bahamas speleothem ∆14C 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 Δ14C 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 ∆14C 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. We present a new speleothem record of atmospheric Δ14C 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 14C ages, using new low-blank ... Article in Journal/Newspaper Greenland Greenland ice core ice core University of Bristol: Bristol Research Earth and Planetary Science Letters 289 1-2 1 10 |
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Open Polar |
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University of Bristol: Bristol Research |
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ftubristolcris |
language |
English |
description |
We present a new speleothem record of atmospheric Δ14C 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 14C ages, using new low-blank protocols, and U–Th ages using high precision MC-ICPMS procedures. Atmospheric Δ14C was calculated by correcting 14C ages with a constant dead carbon fraction (DCF) of 22.7 ± 5.9%, based on a comparison of stalagmite 14C ages with the IntCal04 (Reimer et al., 2004) calibration curve between 15 and 11 ka. The new Δ14C 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 14C data set for a stalagmite record from the Bahamas — GB-89-24-1 (Beck et al., 2001), which likely suffered from 14C analytical blank subtraction issues in the older part of the record. The new Bahamas speleothem ∆14C 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 Δ14C 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 ∆14C 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. We present a new speleothem record of atmospheric Δ14C 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 14C ages, using new low-blank ... |
format |
Article in Journal/Newspaper |
author |
Hoffmann, DL Beck, JW Richards, DA Smart, PL Singarayer, JS Ketchmark, T Hawkesworth, CJ |
spellingShingle |
Hoffmann, DL Beck, JW Richards, DA Smart, PL Singarayer, JS Ketchmark, T Hawkesworth, CJ Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas |
author_facet |
Hoffmann, DL Beck, JW Richards, DA Smart, PL Singarayer, JS Ketchmark, T Hawkesworth, CJ |
author_sort |
Hoffmann, DL |
title |
Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas |
title_short |
Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas |
title_full |
Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas |
title_fullStr |
Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas |
title_full_unstemmed |
Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas |
title_sort |
towards radiocarbon calibration beyond 28 ka based on speleothems from the bahamas |
publishDate |
2010 |
url |
https://hdl.handle.net/1983/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 https://research-information.bris.ac.uk/en/publications/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 https://doi.org/10.1016/j.epsl.2009.10.004 http://www.sciencedirect.com/science/article/pii/S0012821X09006037 |
genre |
Greenland Greenland ice core ice core |
genre_facet |
Greenland Greenland ice core ice core |
op_source |
Hoffmann , DL , Beck , JW , Richards , DA , Smart , PL , Singarayer , JS , Ketchmark , T & Hawkesworth , CJ 2010 , ' Towards radiocarbon calibration beyond 28 ka based on speleothems from the Bahamas ' , Earth and Planetary Science Letters , vol. 289 , no. 1-2 , pp. 1 - 10 . https://doi.org/10.1016/j.epsl.2009.10.004 |
op_relation |
https://research-information.bris.ac.uk/en/publications/ab9363f5-8960-4e2a-997e-7ce1b6be8c24 |
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 |
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1-2 |
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1 |
op_container_end_page |
10 |
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1797584079581872128 |