The sediments deposited during the Bartonian along the drowning ramp of the Provençal- Dauphinois Domain record the Middle Eocene Climatic Optimum (MECO), the prominent global warming event, centered at ~40 Ma and lasting ~400-600 kyrs. These successions offer the crucial opportunity to evaluate the resilience of foraminifera (both planktic and benthic, including larger foraminifera) based on their ecological reactions to the climatic disturbance. Our dataset come from three different successions (Sealza, Capo Mortola and Olivetta San Michele) that, despite being lithostratigraphically and biostratigraphically correlated, depict significant differences in terms of faunal distribution and depositional setting. Planktic foraminiferal assemblages differ in all the successions both in abundance and diversity, suggesting major differences in water circulation in these shallow-water settings. The variations in abundance of Subbotina and Acarinina appear controlled by both the MECO warming and by a moderate eutrophication related to the enhanced hydrological cycle. Benthic taxa fluctuations across the MECO are mostly comparable among the sections. The significant changes in the communities appears mainly influenced by the enhanced fluvial regime and related trophic state rather than by the temperature increase. This is particularly evident in larger foraminifera that reacted positively to the new trophic regime by increasing their abundance and diversity. Being shallow-water biota, they are better adapted to seasonal variations in salinity and temperature more than taxa living in deep-water settings and they are generally more resilient to long-term climatic perturbations. Nonetheless, their population shifts appear more directly impacted by the altered sedimentary rates and nutrient inputs, modulated by the enhanced hydrological cycle triggered by the warming event.
A regional synthesis from the Provençal Domain (western Tethys) on the response of marine calcifiers in shallow-water paleoenvironments across the Middle Eocene Climatic Optimum / Gandolfi, A.; Giraldo-Gómez, V. M.; Arena, L.; Papazzoni, C. A.; Luciani, V.; Pignatti, J.; Piazza, M.; Briguglio, A.. - (2024), pp. 66-66. (Intervento presentato al convegno XXIV Edition of the “Giornate di Paleontologia” Pisa, (4) 5-7 June 2024 tenutosi a Pisa).
A regional synthesis from the Provençal Domain (western Tethys) on the response of marine calcifiers in shallow-water paleoenvironments across the Middle Eocene Climatic Optimum
Pignatti, J.;
2024
Abstract
The sediments deposited during the Bartonian along the drowning ramp of the Provençal- Dauphinois Domain record the Middle Eocene Climatic Optimum (MECO), the prominent global warming event, centered at ~40 Ma and lasting ~400-600 kyrs. These successions offer the crucial opportunity to evaluate the resilience of foraminifera (both planktic and benthic, including larger foraminifera) based on their ecological reactions to the climatic disturbance. Our dataset come from three different successions (Sealza, Capo Mortola and Olivetta San Michele) that, despite being lithostratigraphically and biostratigraphically correlated, depict significant differences in terms of faunal distribution and depositional setting. Planktic foraminiferal assemblages differ in all the successions both in abundance and diversity, suggesting major differences in water circulation in these shallow-water settings. The variations in abundance of Subbotina and Acarinina appear controlled by both the MECO warming and by a moderate eutrophication related to the enhanced hydrological cycle. Benthic taxa fluctuations across the MECO are mostly comparable among the sections. The significant changes in the communities appears mainly influenced by the enhanced fluvial regime and related trophic state rather than by the temperature increase. This is particularly evident in larger foraminifera that reacted positively to the new trophic regime by increasing their abundance and diversity. Being shallow-water biota, they are better adapted to seasonal variations in salinity and temperature more than taxa living in deep-water settings and they are generally more resilient to long-term climatic perturbations. Nonetheless, their population shifts appear more directly impacted by the altered sedimentary rates and nutrient inputs, modulated by the enhanced hydrological cycle triggered by the warming event.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
