Did high Neo-Tethys subduction rates contribute to early Cenozoic warming?
The 58–51 Ma interval was characterized by a long-term increase of global temperatures (+4 to +6 °C) up to the Early Eocene Climate Optimum (EECO, 52.9–50.7 Ma), the warmest interval of the Cenozoic. It was recently suggested that sustained high atmospheric <i>p</i>CO<sub>2</sub...
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Format: | Article |
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Copernicus Publications
2015-12-01
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Series: | Climate of the Past |
Online Access: | http://www.clim-past.net/11/1751/2015/cp-11-1751-2015.pdf |
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author | G. Hoareau B. Bomou D. J. J. van Hinsbergen N. Carry D. Marquer Y. Donnadieu G. Le Hir B. Vrielynck A.-V. Walter-Simonnet |
author_facet | G. Hoareau B. Bomou D. J. J. van Hinsbergen N. Carry D. Marquer Y. Donnadieu G. Le Hir B. Vrielynck A.-V. Walter-Simonnet |
author_sort | G. Hoareau |
collection | DOAJ |
description | The 58–51 Ma interval was characterized by a long-term increase of global
temperatures (+4 to +6 °C) up to the Early Eocene Climate
Optimum (EECO, 52.9–50.7 Ma), the warmest interval of the Cenozoic. It was
recently suggested that sustained high atmospheric <i>p</i>CO<sub>2</sub>, controlling
warm early Cenozoic climate, may have been released during Neo-Tethys
closure through the subduction of large amounts of pelagic carbonates and
their recycling as CO<sub>2</sub> at arc volcanoes. To analyze the impact of
Neo-Tethys closure on early Cenozoic warming, we have modeled the volume of
subducted sediments and the amount of CO<sub>2</sub> emitted along the northern
Tethys margin. The impact of calculated CO<sub>2</sub> fluxes on global
temperature during the early Cenozoic have then been tested using a climate
carbon cycle model (GEOCLIM). We show that CO<sub>2</sub> production may have
reached up to 1.55 × 10<sup>18</sup> mol Ma<sup>−1</sup> specifically during the EECO,
~ 4 to 37 % higher that the modern global volcanic CO<sub>2</sub>
output, owing to a dramatic India-Asia plate convergence increase. The
subduction of thick Greater Indian continental margin carbonate sediments at
~ 55–50 Ma may also have led to additional CO<sub>2</sub> production
of 3.35 × 10<sup>18</sup> mol Ma<sup>−1</sup> during the EECO, making a total of 85 % of the
global volcanic CO<sub>2</sub> outgassed. However, climate modeling demonstrates
that timing of maximum CO<sub>2</sub> release only partially fits with the EECO,
and that corresponding maximum <i>p</i>CO<sub>2</sub> values (750 ppm) and surface warming
(+2 °C) do not reach values inferred from geochemical proxies, a
result consistent with conclusions arising from modeling based on other
published CO<sub>2</sub> fluxes. These results demonstrate that CO<sub>2</sub> derived
from decarbonation of Neo-Tethyan lithosphere may have possibly contributed
to, but certainly cannot account alone for early Cenozoic warming. Other
commonly cited sources of excess CO<sub>2</sub> such as enhanced igneous province
volcanism also appear to be up to 1 order of magnitude below fluxes
required by the model to fit with proxy data of <i>p</i>CO<sub>2</sub> and temperature at
that time. An alternate explanation may be that CO<sub>2</sub> consumption, a key
parameter of the long-term atmospheric <i>p</i>CO<sub>2</sub> balance, may have been
lower than suggested by modeling. These results call for a better
calibration of early Cenozoic weathering rates. |
first_indexed | 2024-04-13T08:54:13Z |
format | Article |
id | doaj.art-2e03d08802c841dca0e62f2ccc46bf17 |
institution | Directory Open Access Journal |
issn | 1814-9324 1814-9332 |
language | English |
last_indexed | 2024-04-13T08:54:13Z |
publishDate | 2015-12-01 |
publisher | Copernicus Publications |
record_format | Article |
series | Climate of the Past |
spelling | doaj.art-2e03d08802c841dca0e62f2ccc46bf172022-12-22T02:53:21ZengCopernicus PublicationsClimate of the Past1814-93241814-93322015-12-0111121751176710.5194/cp-11-1751-2015Did high Neo-Tethys subduction rates contribute to early Cenozoic warming?G. Hoareau0B. Bomou1D. J. J. van Hinsbergen2N. Carry3D. Marquer4Y. Donnadieu5G. Le Hir6B. Vrielynck7A.-V. Walter-Simonnet8UMR 6249 Chrono-environnement (CNRS-Université de Franche-Comté), 25030 Besançon CEDEX, FranceUMR 6249 Chrono-environnement (CNRS-Université de Franche-Comté), 25030 Besançon CEDEX, FranceDepartment of Earth Sciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, the NetherlandsUMR 6249 Chrono-environnement (CNRS-Université de Franche-Comté), 25030 Besançon CEDEX, FranceUMR 6249 Chrono-environnement (CNRS-Université de Franche-Comté), 25030 Besançon CEDEX, FranceLSCE/UVSQ/IPSL CEA Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette, FranceInstitut de Physique du Globe de Paris, 4 place Jussieu, 75005 Paris, FranceUMR 7193 – ISTEP (CNRS-UPMC), 4 place Jussieu, 75252 Paris CEDEX 05, FranceUMR 6249 Chrono-environnement (CNRS-Université de Franche-Comté), 25030 Besançon CEDEX, FranceThe 58–51 Ma interval was characterized by a long-term increase of global temperatures (+4 to +6 °C) up to the Early Eocene Climate Optimum (EECO, 52.9–50.7 Ma), the warmest interval of the Cenozoic. It was recently suggested that sustained high atmospheric <i>p</i>CO<sub>2</sub>, controlling warm early Cenozoic climate, may have been released during Neo-Tethys closure through the subduction of large amounts of pelagic carbonates and their recycling as CO<sub>2</sub> at arc volcanoes. To analyze the impact of Neo-Tethys closure on early Cenozoic warming, we have modeled the volume of subducted sediments and the amount of CO<sub>2</sub> emitted along the northern Tethys margin. The impact of calculated CO<sub>2</sub> fluxes on global temperature during the early Cenozoic have then been tested using a climate carbon cycle model (GEOCLIM). We show that CO<sub>2</sub> production may have reached up to 1.55 × 10<sup>18</sup> mol Ma<sup>−1</sup> specifically during the EECO, ~ 4 to 37 % higher that the modern global volcanic CO<sub>2</sub> output, owing to a dramatic India-Asia plate convergence increase. The subduction of thick Greater Indian continental margin carbonate sediments at ~ 55–50 Ma may also have led to additional CO<sub>2</sub> production of 3.35 × 10<sup>18</sup> mol Ma<sup>−1</sup> during the EECO, making a total of 85 % of the global volcanic CO<sub>2</sub> outgassed. However, climate modeling demonstrates that timing of maximum CO<sub>2</sub> release only partially fits with the EECO, and that corresponding maximum <i>p</i>CO<sub>2</sub> values (750 ppm) and surface warming (+2 °C) do not reach values inferred from geochemical proxies, a result consistent with conclusions arising from modeling based on other published CO<sub>2</sub> fluxes. These results demonstrate that CO<sub>2</sub> derived from decarbonation of Neo-Tethyan lithosphere may have possibly contributed to, but certainly cannot account alone for early Cenozoic warming. Other commonly cited sources of excess CO<sub>2</sub> such as enhanced igneous province volcanism also appear to be up to 1 order of magnitude below fluxes required by the model to fit with proxy data of <i>p</i>CO<sub>2</sub> and temperature at that time. An alternate explanation may be that CO<sub>2</sub> consumption, a key parameter of the long-term atmospheric <i>p</i>CO<sub>2</sub> balance, may have been lower than suggested by modeling. These results call for a better calibration of early Cenozoic weathering rates.http://www.clim-past.net/11/1751/2015/cp-11-1751-2015.pdf |
spellingShingle | G. Hoareau B. Bomou D. J. J. van Hinsbergen N. Carry D. Marquer Y. Donnadieu G. Le Hir B. Vrielynck A.-V. Walter-Simonnet Did high Neo-Tethys subduction rates contribute to early Cenozoic warming? Climate of the Past |
title | Did high Neo-Tethys subduction rates contribute to early Cenozoic warming? |
title_full | Did high Neo-Tethys subduction rates contribute to early Cenozoic warming? |
title_fullStr | Did high Neo-Tethys subduction rates contribute to early Cenozoic warming? |
title_full_unstemmed | Did high Neo-Tethys subduction rates contribute to early Cenozoic warming? |
title_short | Did high Neo-Tethys subduction rates contribute to early Cenozoic warming? |
title_sort | did high neo tethys subduction rates contribute to early cenozoic warming |
url | http://www.clim-past.net/11/1751/2015/cp-11-1751-2015.pdf |
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