Tephrochronological constraints on the timing and nature of sea-level change prior to and during glacial termination V

• Published in: Quaternary Science Reviews
• Main Authors: Giaccio, Biagio, Marino, Gianluca, Marra, Fabrizio, Monaco, Lorenzo, Pereira, Alison, Zanchetta, Giovanni, Gaeta, Mario, Leicher, Niklas, Nomade, Sébastien, Palladino, Danilo, Sottili, Gianluca, Guillou, Hervé, Scao, Vincent
• Other Authors: Istituto di Geologia Ambientale e Geoingegneria (IGAG), National Research Council of Italy, Universidade de Vigo, Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Roma (INGV), Istituto Nazionale di Geofisica e Vulcanologia, Dipartimento di Scienze della Terra, Università degli Studi di Roma "La Sapienza" = Sapienza University Rome (UNIROMA), Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Scienze della Terra Pisa, University of Pisa - Università di Pisa, University of Cologne, Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Paléocéanographie (PALEOCEAN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), G.M. acknowledges support from the University of Vigo's programme to attract excellent research talent (RR04092017), a Beatriz Galindo Fellowship (2020), and a generous start-up package.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: MIS 12 to MIS 11 transition; Aggradational successions; Meltwater pulse events; Heinrich-like events; Middle pleistocene; 40Ar/39Ar geochronology; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDE.MCG]Environmental Sciences/Global Changes; [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy; Tiber; North Atlantic
• Online Access: https://hal.science/hal-03233481; https://hal.science/hal-03233481/document; https://hal.science/hal-03233481/file/Giaccio%2Bet%2Bal_QSR_28-01-2021.pdf; https://doi.org/10.1016/j.quascirev.2021.106976

International audience Glacial-interglacial variations in ice volume and sea level are essential components of the Pleistocene global climate evolution. Deciphering the timing of change of these key climate parameters with respect to the insolation forcing is central to understanding the processes controlling glacial terminations. Here we exploit the sensitivity of the Paleo Tiber River (central Italy) to sea-level forced changes in the base level and the frequent occurrence of datable tephra layers in its sedimentary successions to reconstruct the timing of the relative sea-level (RSL) change between 450 and 403 ka, i.e., across the glacial termination (T-V) that marks the transition between Marine Isotope Stage (MIS) 12 and MIS 11. The analysis hinges on new stratigraphic data, tephra geochemical fingerprinting, and 40Ar/39Ar dating from a fluvial section that represents the inland counterpart of the near mouth, coastal aggradational successions of the San Paolo Formation (SPF). Tephra correlation indicates that the morpho-stratigraphic record of the inland section is as sensitive to the sea-level change as its coastal counterparts, which makes it ideal to complement previous RSL reconstructions from the Tiber River catchment basin, thereby providing a more detailed picture of the sea-level history across T-V. Combined sedimentological and morphological proxies of the composed inland-coastal SPF record document the occurrence of two phases of relatively rapid sea-level rise, here interpreted as meltwater pulse (MWP) events. The earlier MWP occurred between ∼450 and ∼445 ka and matches a relatively minor episode of the sea-level rise documented in an existing RSL record, while the younger MWP at ∼430 ka corresponds to the high amplitude sea-level rise that marks T-V. We find that both MWPs coincide with episodes of ice-rafted debris deposition in the North Atlantic (Heinrich-like events) and with attendant Southern Hemisphere warming, plausibly associated with the bipolar seesaw.