Determining soil sources by organic matter EPR fingerprints in two modern speleothems

摘要: Organic matter (OM) sources and transfers are critical questions at the crossroad of ecology, hydrology paleoenvironmental studies in karst environments. Recently chemical or isotopic characterisations these organic matters have demonstrated their diversity water speleothems. However, knowledge origin transfer from soil needs to be improved especially environments where a mosaic soils occurs. Here we investigate applicability Electron Paramagnetic Resonance (EPR) signature OM seek different fingerprints The positions shapes semiquinone-type radical’s EPR lines considered as robust through compartment ecosystems. We demonstrate that combination simulation constitutes fingerprint discriminates folic Leptosol developed on limestone outcrops eutric Cambisols located dolines topographical depressions. also report conservation thinner after extraction soils. Finally, signatures were detected two speleothems sampled near each other: stalagmite subaqueous flowstone. An unexpected two-orders-of-magnitude discrepancy between free radical concentrations flowstone one hand, low concentration samples other, was ascribed kinetics conformational changes occurring during either fast slow pathways. A found conversely, an Cambisol sample. This difference sample masking (due radicals) case fact clearly shows is sole source OM. remains steady over last four centuries covered by demonstrating stable growth period strengthening interest entrapped speleothem for paleoenvironment studies.