| Title: |
Using extra-terrestrial 3He to reconstruct terrigenous fluxes and their impacts on marine primary productivity and carbon burial during OAE2 |
| Authors: |
Godet, Blandine; Blard, P.; Suan, Guillaume; Suchéras-Marx, Baptiste; Riquier, Laurent; Tibari, Bouchaïb; Martinez, Mathieu |
| Contributors: |
Centre de Recherches Pétrographiques et Géochimiques (CRPG); Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS); Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE); École normale supérieure de Lyon (ENS de Lyon); Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL); Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS); Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE); Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE); Institut des Sciences de la Terre de Paris (iSTeP); Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY); Centre National de la Recherche Scientifique (CNRS); Université de Lorraine (UL); Institut national des sciences de l'Univers (INSU - CNRS); Géosciences Rennes (GR); Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des sciences de l'environnement de Rennes (OSERen); Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE); MarlHe – Marl-Limestone alternation formation reconstruction based on 3HeET - CNRS Terre et Univers |
| Source: |
EGU General Assembly 2025 ; https://hal.science/hal-04871297 ; EGU General Assembly 2025, Apr 2025, Vienne (Autriche), Austria. pp.EGU25-3672, ⟨10.5194/egusphere-egu25-3672⟩ |
| Publisher Information: |
CCSD |
| Publication Year: |
2025 |
| Collection: |
Archive Ouverte de l'Université Rennes (HAL) |
| Subject Terms: |
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy |
| Subject Geographic: |
Vienne (Autriche); Austria |
| Description: |
International audience ; The Mesozoic was punctuated by several Oceanic Anoxic Events (OAE) characterised by widespread black shale deposition and global carbon cycle perturbations. Among them, the OAE2 spanning the Cenomanian-Turonian boundary (~ 94 Ma), has been identified as one of the most severe OAE of the Mesozoic. The OAE2 is characterised by a global > 2‰ positive carbon isotope excursion (CIE ) recorded in both inorganic and organic sedimentary material. This CIE is interpreted as a massive burial of 13C-depeleted organic carbon driven by a global decrease in seafloor oxygenation. Previous models suggested that volcanism related to Large Igneous Provinces (LIPs) increased atmospheric CO2 concentrations, thereby increasing, through enhanced continental weathering, oceanic nutrient and primary production in superficial waters, ultimately leading to higher oxygen consumption at depth. However, the role of enhanced weathering and accelerated continental fluxes on marine primary productivity and organic carbon burial during OAE2 remains highly debated, largely due to the difficulty of reconstructing highly resolved changes in terrigenous and organic fluxes from sedimentary records. In this study, we use new extra-terrestrial 3He (3HeET) measurements from hemipelagic marine samples from Pont d’Issole (Vocontian Basin) and Cuba (Western Interior Basin) sections to reconstruct carbonate, organic carbon and terrigenous sedimentation rates and fluxes across the OAE2. Our results from Pont d’Issole reveal that over 70 % of the 3He in the analysed samples is extra-terrestrial in origin. Assuming a constant flux of 3HeET-bearing Interplanetary Dust Particles, we used 3HeET concentrations to reconstruct relative changes in sedimentation rates at an unprecedented high resolution (every 15 cm / 5 ka). Our preliminary results indicate constant terrigenous fluxes (ca 1.6 g/cm²/ka) across different carbonate-rich and carbonate-poor lithologies prior to and across the OAE2 onset. On the contrary, carbonate fluxes ... |
| Document Type: |
conference object |
| Language: |
English |
| DOI: |
10.5194/egusphere-egu25-3672 |
| Availability: |
https://hal.science/hal-04871297; https://doi.org/10.5194/egusphere-egu25-3672 |
| Rights: |
http://creativecommons.org/licenses/by-nc-sa/ |
| Accession Number: |
edsbas.7649372D |
| Database: |
BASE |