Titre :

Revisiting the fingerprint of organic matters in speleothem by Electron Paramagnetic Resonance

Auteur(s) :

Perrette, Yves [Auteur]
Environnements, Dynamiques et Territoires de Montagne [EDYTEM]
Vezin, Herve [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Fanget, Bernard [Auteur]
Environnements, Dynamiques et Territoires de Montagne [EDYTEM]
Garagnon, Julia [Auteur]
Environnements, Dynamiques et Territoires de Montagne [EDYTEM]
Poulenard, Jérome [Auteur]
Environnements, Dynamiques et Territoires de Montagne [EDYTEM]

Titre de la revue :

Organic Geochemistry

Nom court de la revue :

Organic Geochemistry

Numéro :

201

Pagination :

104929

Éditeur :

Elsevier

Date de publication :

2025-03

ISSN :

0146-6380

Mot(s)-clé(s) en anglais :

Soil organic matter
Electron Paramagnetic Resonance spectroscopy
UV fluorescence spectroscopy
Speleothems

Discipline(s) HAL :

Chimie/Chimie théorique et/ou physique
Sciences de l'environnement
Sciences de l'environnement/Milieux et Changements globaux

Résumé en anglais : [en]

The evolution of soil organic carbon (SOC) stocks is critical for both food production and climate change mitigation. This study uses advanced electron paramagnetic resonance (EPR) spectroscopy to investigate the spatial ...
Lire la suite >The evolution of soil organic carbon (SOC) stocks is critical for both food production and climate change mitigation. This study uses advanced electron paramagnetic resonance (EPR) spectroscopy to investigate the spatial localisation and characterisation of organic carbon in speleothems, with a particular focus on methodological advances in recent decades. A speleothem sample from the Choranche cave in France was analysed using UV laser-induced fluorescence (LIF) and continuous wave EPR spectroscopy. The LIF analysis identified three main types of organic compounds − aromatic amino acids, aliphatic aromatics and larger aromatic compounds − distributed throughout the sample. EPR spectroscopy revealed the presence of Fe3+ and Mn2+ ions, along the entire sample for Fe3+ and more localised for Mn2+. When radical organic matter (ROM) is detected, first and second harmonic EPR imaging shows its collocation with Fe3+ and Mn2+, suggesting specific embedding conditions or source events. The study highlights a significant discrepancy between fluorescent organic matter (FOM) and ROM, challenging previous assumptions about their co-transfer from soil to speleothems. The results suggest that ROM is likely to be associated with specific soil redox conditions or high-energy events, whereas FOM represents a continuous background transfer. This distinction is crucial for accurate interpretations of soil organic carbon loss and its environmental implications. Future research should integrate detailed spectroscopic and isotopic analyses to better quantify organic carbon dynamics and their environmental proxies. Our results highlight the importance of distinguishing between different types of organic matter in speleothems to improve our understanding of soil organic carbon fluxes in relation to climate and human land use.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
CNRS

Collections :

• Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516

Équipe(s) de recherche :

Propriétés magnéto structurales des matériaux (PMSM)

Date de dépôt :

2025-01-17T09:42:56Z
2025-01-17T10:41:31Z