Browsing by Author "Capraro, Luca"
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- Monsoon variability and high latitude climate signals in the Central Mediterranean at the Pliocene- Pleistocene transition: The Gelasian stratotype section (Monte San Nicola, Sicily) [Global and Planetary Change, volume 249, 104788]: CommentPublication . Zanola, Elena; Bonomo, Sergio; Incarbona, Alessandro; Tesei, Telemaco; Stefano, Agata Di; Ferretti, Patrizia; Fornaciari, Eliana; Galeotti, Simone; Macrì, Patrizia; Raffi, Isabella; Rodrigues, Teresa; Speranza, Fabio; Stefano, Enrico Di; Sprovieri, Rodolfo; Rio, Domenico; Capraro, LucaThe stratigraphic record of Monte San Nicola (southern Sicily, Italy), where the Global Boundary Stratotype Section and Point (GSSP) for the Gelasian Stage (Lower Pleistocene) has been defined, has been studied by our research group for fifteen years. In 2021, another working group (GELSTRAT) started investigating the Monte San Nicola stratigraphy in a location close to the GSSP section, with results that differ significantly from those published by our team. In particular, major discrepancies in the alkenone-derived paleotemperature reconstructions led the GELSTRAT team to suggest that our age model is invalid, and they inferred that we had made a wrong interpretation of the physical stratigraphic record. In this comment, we demonstrate that our chronological model is correct, while the stratigraphic profile studied by the GELSTRAT team should be approached with care, due to the presence of tectonic displacements, truncations, and uncertain lithological evidence for critical marker beds, such as the sapropel layers below the Nicola bed.
- Orbital and suborbital temperature variability in the central Mediterranean across the Pliocene/Pleistocene transitionPublication . Zanola, Elena; Rodrigues, Teresa; Bonomo, Sergio; Ferretti, Patrizia; Fornaciari, Eliana; Stefano, Agata Di; Incarbona, Alessandro; Preto, Nereo; Raffi, Isabella; Capraro, Luca; Jessica L. OsterA high-resolution record of central Mediterranean Sea Surface Temperatures (SSTs) based on the alkenone U-37(K') index and planktic delta O-18 values for the surface-dweller G. ruber has been reconstructed across the Pliocene/Pleistocene transition at Monte San Nicola (Sicily), reference area for the GSSP (Global Boundary Stratotype Section and Point) of the Gelasian Stage. Spectral analyses indicate that the SST record is predominantly paced by a cyclicity in the similar to 47 kyr time domain, consistent with the obliquity driven glacial-interglacial variability that is expected to dominate in the interval of relevance. In addition, two suborbital periodicities in the similar to 5 kyr and similar to 8 kyr time domains provide a pervasive spectral signal that proves to be especially strong during the MIS (Marine Isotope Stage) 100 glacial, at the inception of the Northern Hemisphere Glaciation. This high frequency climatic instability, a prominent feature of the early Gelasian, might reflect episodic events of massive disruption of the Atlantic Meridional Overturning Circulation with increased production of cold, low-salinity water masses in the North Atlantic. Alternatively, it may be interpreted as the resonance (i.e., harmonics) of the low-latitude precessional forcing in mid-latitude regions. Although the driving mechanisms of these processes remain largely unconstrained, our study emphasizes the role of the central Mediterranean as the main reference for high-resolution paleoclimatic studies in the Neogene and the Quaternary.