Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution

In this study, the ‘dead carbon proportion’ (DCP) calculated from combined U-Th and radiocarbon analyses was used to explore the carbon isotope systematics in Corchia Cave (Italy) speleothems, using the example of stalagmite CC26 which grew during the last ∼12 ka. The DCP values in CC26 are among th...

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Published in:Geochimica et Cosmochimica Acta
Main Authors: Bajo, Petra, Borsato, Andrea, Drysdale, Russell, Hua, Quan
Format: Text
Language:unknown
Published: Digital Commons @ University of South Florida 2017
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Online Access:https://digitalcommons.usf.edu/kip_articles/7223
https://doi.org/10.1016/j.gca.2017.04.038
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spelling ftunisfloridatam:oai:digitalcommons.usf.edu:kip_articles-8223 2023-12-10T09:47:37+01:00 Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution Bajo, Petra Borsato, Andrea Drysdale, Russell Hua, Quan 2017-01-01T08:00:00Z https://digitalcommons.usf.edu/kip_articles/7223 https://doi.org/10.1016/j.gca.2017.04.038 unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/kip_articles/7223 doi:10.1016/j.gca.2017.04.038 https://doi.org/10.1016/j.gca.2017.04.038 KIP Articles text 2017 ftunisfloridatam https://doi.org/10.1016/j.gca.2017.04.038 2023-11-16T19:07:43Z In this study, the ‘dead carbon proportion’ (DCP) calculated from combined U-Th and radiocarbon analyses was used to explore the carbon isotope systematics in Corchia Cave (Italy) speleothems, using the example of stalagmite CC26 which grew during the last ∼12 ka. The DCP values in CC26 are among the highest ever recorded in a stalagmite, spanning the range 44.8–68.8%. A combination of almost closed-system conditions and sulphuric acid dissolution (SAD) are proposed as major drivers in producing such a high DCP with minor contribution from old organic matter from the deep vadose zone. The long-term decrease in both DCP and δ13C most likely reflects post-glacial soil recovery above the cave, with a progressive increase of soil CO2 contribution to the total dissolved inorganic carbon (DIC). Pronounced millennial-scale shifts in DCP and relatively small coeval but antipathetic changes in δ13C are modulated by the effects of hydrological variability on open and closed-system dissolution, SAD and prior calcite precipitation. Hence, the DCP in Corchia Cave speleothems represents an additional proxy for rainfall amount. Text Carbonic acid Digital Commons University of South Florida (USF) Geochimica et Cosmochimica Acta 210 208 227
institution Open Polar
collection Digital Commons University of South Florida (USF)
op_collection_id ftunisfloridatam
language unknown
description In this study, the ‘dead carbon proportion’ (DCP) calculated from combined U-Th and radiocarbon analyses was used to explore the carbon isotope systematics in Corchia Cave (Italy) speleothems, using the example of stalagmite CC26 which grew during the last ∼12 ka. The DCP values in CC26 are among the highest ever recorded in a stalagmite, spanning the range 44.8–68.8%. A combination of almost closed-system conditions and sulphuric acid dissolution (SAD) are proposed as major drivers in producing such a high DCP with minor contribution from old organic matter from the deep vadose zone. The long-term decrease in both DCP and δ13C most likely reflects post-glacial soil recovery above the cave, with a progressive increase of soil CO2 contribution to the total dissolved inorganic carbon (DIC). Pronounced millennial-scale shifts in DCP and relatively small coeval but antipathetic changes in δ13C are modulated by the effects of hydrological variability on open and closed-system dissolution, SAD and prior calcite precipitation. Hence, the DCP in Corchia Cave speleothems represents an additional proxy for rainfall amount.
format Text
author Bajo, Petra
Borsato, Andrea
Drysdale, Russell
Hua, Quan
spellingShingle Bajo, Petra
Borsato, Andrea
Drysdale, Russell
Hua, Quan
Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution
author_facet Bajo, Petra
Borsato, Andrea
Drysdale, Russell
Hua, Quan
author_sort Bajo, Petra
title Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution
title_short Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution
title_full Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution
title_fullStr Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution
title_full_unstemmed Stalagmite carbon isotopes and dead carbon proportion (DCP) in a near-closed-system situation: An interplay between sulphuric and carbonic acid dissolution
title_sort stalagmite carbon isotopes and dead carbon proportion (dcp) in a near-closed-system situation: an interplay between sulphuric and carbonic acid dissolution
publisher Digital Commons @ University of South Florida
publishDate 2017
url https://digitalcommons.usf.edu/kip_articles/7223
https://doi.org/10.1016/j.gca.2017.04.038
genre Carbonic acid
genre_facet Carbonic acid
op_source KIP Articles
op_relation https://digitalcommons.usf.edu/kip_articles/7223
doi:10.1016/j.gca.2017.04.038
https://doi.org/10.1016/j.gca.2017.04.038
op_doi https://doi.org/10.1016/j.gca.2017.04.038
container_title Geochimica et Cosmochimica Acta
container_volume 210
container_start_page 208
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