Mercury enrichments of the Pyrenean foreland basins sediments support enhanced volcanism during the Paleocene-Eocene thermal maximum (PETM)

Details

Ressource 1Download: Tremblin et al_Mercury-Pyrenean foreland basins_PETM.pdf (9786.21 [Ko])
State: Public
Version: Final published version
License: CC BY 4.0
Serval ID
serval:BIB_5F674B12D8FF
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Mercury enrichments of the Pyrenean foreland basins sediments support enhanced volcanism during the Paleocene-Eocene thermal maximum (PETM)
Journal
Global and Planetary Change
Author(s)
Tremblin M., Khozyem H., Adatte T., Spangenberg J. E., Fillon C., Grauls A., Hunger T., Nowak A., Läuchli C., Lasseur E., Roig J.-Y., Serrano O., Calassou S., Guillocheau F., Castelltort S.
ISSN
0921-8181
Publication state
Published
Issued date
05/2022
Peer-reviewed
Oui
Volume
212
Pages
103794
Language
english
Abstract
The Paleogene records the most prominent global climate change of the Cenozoic Era with a shift from a greenhouse to an icehouse world. Several transient hyperthermal events punctuated this long-term evolution. The most pronounced and the best known of these is the Paleocene-Eocene Thermal Maximum (PETM-56 Ma). This event is associated with global warming, a worldwide perturbation of the carbon cycle, and significant biotic changes. The PETM is primarily recorded by a sharp negative carbon isotope excursion (NCIE) in both carbonates and organic matter of sedimentary successions. The source of the 13C-depleted carbon for the NCIE and whether it was released in one or numerous events is still debated. Several carbon sources have been proposed to explain the PETM-NCIE and the mechanisms that triggered this abrupt climate upheaval. These include, among others, the magmatic and thermogenic release of carbon associated with the emplacement of Large Igneous Provinces (LIP). One proxy for tracking past volcanic emissions in the geological record and testing hypothetical links between volcanism and hyperthermals is the use of mercury (Hg) anomalies found in marine and continental sedimentary successions. Here, we present new high-resolution mercury and stable isotopic records from a continental-marine transect in Pyrenean peripheral basins during the PETM. Compared to deeper marine settings, the significant sedimentation rate that characterizes these high-accommodation and high sediment-supply environments allows the preservation of expanded successions, providing reliable information about the fluctuations of Hg concentration in deposits across the PETM. Our data reveal two large negative carbon excursions across the studied successions. Based on biostratigraphy and the similarity of shape and amplitude of the isotopic excursions with global records, we interpret the largest NCIE as the PETM. This main excursion is preceded by another that we interpret as the Pre-Onset Excursion (POE), found in other profiles worldwide. We find that the POE and the PETM are, in our studied sections, systematically associated with significant Hg anomalies regardless of the depositional environment. These results suggest that large pulses of volcanism, possibly related to the North Atlantic Igneous Province's emplacement, contributed to the onset and possibly also to the long duration of the PETM. Furthermore, the record of higher Hg anomalies in nearshore than offshore settings suggests a massive collapse of terrestrial ecosystems linked to volcanism-driven environmental change triggered significant Hg loading in shallow marine ecosystems. If this is correct, these findings confirm the primary role of the solid Earth in determining past terrestrial climates.
Keywords
Oceanography, Global and Planetary Change
Web of science
Open Access
Yes
Create date
10/06/2022 10:51
Last modification date
17/06/2022 6:35
Usage data