Sediment Chronology in Antarctic Deglacial Sediments: Reconciling Organic Carbon 14 C Ages to Carbonate 14 C Ages Using Ramped PyrOx
We present the first study which directly compares carbonate radiocarbon (14C) dates with the Ramped PyrOx (RP) radiocarbon dating technique within a single sediment core, and we confirm the utility for the latter constructing chronologies of high latitude, Holocene marine margin sediment succession...
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Digital Commons @ University of South Florida
2022
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Online Access: | https://digitalcommons.usf.edu/msc_facpub/2445 https://doi.org/10.1177/0959683615608688 |
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ftusouthflorida:oai:digitalcommons.usf.edu:msc_facpub-3443 2023-07-30T03:57:49+02:00 Sediment Chronology in Antarctic Deglacial Sediments: Reconciling Organic Carbon 14 C Ages to Carbonate 14 C Ages Using Ramped PyrOx Subt, Cristina Fangman, Kimberly A Wellner, Julia S Rosenheim, Brad E 2022-01-01T08:00:00Z https://digitalcommons.usf.edu/msc_facpub/2445 https://doi.org/10.1177/0959683615608688 unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/2445 doi:10.1177/0959683615608688 https://doi.org/10.1177/0959683615608688 Marine Science Faculty Publications Antarctic bulk acid insoluble organic fraction deglacial sediment radiocarbon dating Ramped PyrOx Life Sciences article 2022 ftusouthflorida https://doi.org/10.1177/0959683615608688 2023-07-13T21:07:48Z We present the first study which directly compares carbonate radiocarbon (14C) dates with the Ramped PyrOx (RP) radiocarbon dating technique within a single sediment core, and we confirm the utility for the latter constructing chronologies of high latitude, Holocene marine margin sediment successions. Historically, the heavily detrital nature of Antarctic margin sedimentary organic material and lack of carbonate preservation have made these sediments difficult to date accurately. Here, we use archived cores with existing foraminiferal ages to compare with RP dates at equal or similar depth intervals. The lowest temperature RP splits were integrated over narrower intervals than in previous studies to reduce the amount of mixing with older, more thermochemically stable end-members during pyrolytic decomposition. Ages of the low-temperature RP splits coincide with their corresponding carbonate counterparts, suggesting that the RP 14C dating method is a reliable alternative to carbonate dates in sediments where carbonates are absent or not sufficiently preserved for 14C dating. The rarity of calcareous material in most Antarctic sediments often obligates the use of the bulk acid insoluble organic (AIO) fraction of the sediment, which can be problematic because of contamination by older carbon. The bulk AIO 14C ages, which are calculated using the weighted arithmetic mean of all RP splits of individual samples, show that age reversals and biases can occur using bulk AIO dates for age models because of variable proportions of pre-aged organic matter down-core. The application of the RP dating method can reduce these effects to produce a more reliable chronology that is statistically identical to the foraminiferal dating chronology. Article in Journal/Newspaper Antarc* Antarctic University of South Florida St. Petersburg: Digital USFSP Antarctic The Holocene 26 2 265 273 |
institution |
Open Polar |
collection |
University of South Florida St. Petersburg: Digital USFSP |
op_collection_id |
ftusouthflorida |
language |
unknown |
topic |
Antarctic bulk acid insoluble organic fraction deglacial sediment radiocarbon dating Ramped PyrOx Life Sciences |
spellingShingle |
Antarctic bulk acid insoluble organic fraction deglacial sediment radiocarbon dating Ramped PyrOx Life Sciences Subt, Cristina Fangman, Kimberly A Wellner, Julia S Rosenheim, Brad E Sediment Chronology in Antarctic Deglacial Sediments: Reconciling Organic Carbon 14 C Ages to Carbonate 14 C Ages Using Ramped PyrOx |
topic_facet |
Antarctic bulk acid insoluble organic fraction deglacial sediment radiocarbon dating Ramped PyrOx Life Sciences |
description |
We present the first study which directly compares carbonate radiocarbon (14C) dates with the Ramped PyrOx (RP) radiocarbon dating technique within a single sediment core, and we confirm the utility for the latter constructing chronologies of high latitude, Holocene marine margin sediment successions. Historically, the heavily detrital nature of Antarctic margin sedimentary organic material and lack of carbonate preservation have made these sediments difficult to date accurately. Here, we use archived cores with existing foraminiferal ages to compare with RP dates at equal or similar depth intervals. The lowest temperature RP splits were integrated over narrower intervals than in previous studies to reduce the amount of mixing with older, more thermochemically stable end-members during pyrolytic decomposition. Ages of the low-temperature RP splits coincide with their corresponding carbonate counterparts, suggesting that the RP 14C dating method is a reliable alternative to carbonate dates in sediments where carbonates are absent or not sufficiently preserved for 14C dating. The rarity of calcareous material in most Antarctic sediments often obligates the use of the bulk acid insoluble organic (AIO) fraction of the sediment, which can be problematic because of contamination by older carbon. The bulk AIO 14C ages, which are calculated using the weighted arithmetic mean of all RP splits of individual samples, show that age reversals and biases can occur using bulk AIO dates for age models because of variable proportions of pre-aged organic matter down-core. The application of the RP dating method can reduce these effects to produce a more reliable chronology that is statistically identical to the foraminiferal dating chronology. |
format |
Article in Journal/Newspaper |
author |
Subt, Cristina Fangman, Kimberly A Wellner, Julia S Rosenheim, Brad E |
author_facet |
Subt, Cristina Fangman, Kimberly A Wellner, Julia S Rosenheim, Brad E |
author_sort |
Subt, Cristina |
title |
Sediment Chronology in Antarctic Deglacial Sediments: Reconciling Organic Carbon 14 C Ages to Carbonate 14 C Ages Using Ramped PyrOx |
title_short |
Sediment Chronology in Antarctic Deglacial Sediments: Reconciling Organic Carbon 14 C Ages to Carbonate 14 C Ages Using Ramped PyrOx |
title_full |
Sediment Chronology in Antarctic Deglacial Sediments: Reconciling Organic Carbon 14 C Ages to Carbonate 14 C Ages Using Ramped PyrOx |
title_fullStr |
Sediment Chronology in Antarctic Deglacial Sediments: Reconciling Organic Carbon 14 C Ages to Carbonate 14 C Ages Using Ramped PyrOx |
title_full_unstemmed |
Sediment Chronology in Antarctic Deglacial Sediments: Reconciling Organic Carbon 14 C Ages to Carbonate 14 C Ages Using Ramped PyrOx |
title_sort |
sediment chronology in antarctic deglacial sediments: reconciling organic carbon 14 c ages to carbonate 14 c ages using ramped pyrox |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2022 |
url |
https://digitalcommons.usf.edu/msc_facpub/2445 https://doi.org/10.1177/0959683615608688 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/2445 doi:10.1177/0959683615608688 https://doi.org/10.1177/0959683615608688 |
op_doi |
https://doi.org/10.1177/0959683615608688 |
container_title |
The Holocene |
container_volume |
26 |
container_issue |
2 |
container_start_page |
265 |
op_container_end_page |
273 |
_version_ |
1772819600809918464 |