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Sprovieri, Rodolfo
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Sprovieri, Rodolfo
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- PublicationOpen AccessCalcareous Nannofossil variability controlled by Milankovitch and sub-Milankovitch periodicity in the Monte San Nicola section (Gelasian GSSP / MIS 100–104)(2024-09)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ;; ; ; ; ;The Quaternary marks the beginning of the ice ages, with the establishment of a stable Northern Hemisphere ice sheet. The Monte San Nicola section, southern Sicily (Italy) is the Global Boundary Stratotype Section and Point of the Gelasian Stage of the Lower Quaternary Subseries and is attracting new attention for providing valuable information on paleoclimate evolution. Here we present a paleoenvironmental reconstruction based on new data from calcareous nannoplankton, the phytoplankton organisms that are sensitive to sea surface changes and water column dynamics. We adopt statistical and signal analysis to support our paleoenvironmental model. The most evident paleoenvironmental signal throughout the investigated interval is the contrast between the abundance patterns of placoliths and F. profunda, the former pointing to surface productivity (water column mixing, shallow nutricline), the latter to the establishment of a deep nutricline. The observed nutricline depth shift occurred with a regular precessional pace, following Northern Hemisphere summer insolation and, likely, North African monsoon activity. A significant periodicity of 8 kyr, in tune with late Quaternary Heinrich events, is also observed in nannoplankton taxa, supporting previous findings on the existence of suborbital climatic variability even at the Pliocene-Pleistocene transition.14 2 - PublicationRestrictedVariability in the vertical structure of the water column and paleoproductivity reconstruction in the central-western Mediterranean during the Late Pleistocene(2008-09)
; ; ; ; ; ; ; ;Incarbona, A.; Università degli Studi di Palermo, Dipartimento di Geologia e Geodesia, Via Archirafi 22, 90134 Palermo, Italy ;Di Stefano, E.; Università degli Studi di Palermo, Dipartimento di Geologia e Geodesia, Via Archirafi 22, 90134 Palermo, Italy ;Sprovieri, R.; Università degli Studi di Palermo, Dipartimento di Geologia e Geodesia, Via Archirafi 22, 90134 Palermo, Italy ;Bonomo, S.; Università degli Studi di Palermo, Dipartimento di Geologia e Geodesia, Via Archirafi 22, 90134 Palermo, Italy ;Censi, P.; Università degli Studi di Catania, Dipartimento di Scienze Geologiche, C.so Italia 155, 95129 Catania, Italy ;Dinarès-Turell, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Spoto, S.; Università degli Studi di Catania, Dipartimento di Scienze Geologiche, C.so Italia 155, 95129 Catania, Italy; ; ; ; ; ; A sedimentary sequence spanning Marine Isotope Stage (MIS) 6 to MIS 2 in core LC07, recovered in the central Mediterranean, has been investigated in order to produce a high-resolution paleoceanographic reconstruction. The changes in productivity deduced from calcareous plankton relative abundances and independently confirmed by the BaXS fluctuations are linked to the stability of the water column which is mainly controlled by the water mass temperature. During glacial intervals, productivity was generally enhanced. Oligotrophic and warmer water masses with a deepened seasonal thermocline can be inferred for most of MIS5. The magnetic properties of the sediment show increased occurrences of North Africa dust in the central Mediterranean during cold phases, likely as a consequence of a more efficient erosive process triggered by southward displacement of the intertropical convergence zone. Although increases in both productivity and Saharan dust occurred during cold periods, the atmospheric inputs do not seem to contribute significantly to the fertilization of primary producers. A Shannon Index curve has been used to tentatively synthesize the variations of calcareous nannofossil assemblages through the last 150 kyr. The assemblage diversity sharply increased coincident with the transition from the penultimate glacial to the last interglacial, subsequently low diversity was gradually reached again in the last glacial.230 43 - PublicationEmbargoHigh-resolution climate variability across the Piacenzian/Gelasian boundary in the Monte San Nicola section (Sicily, Italy)(2024-01-15)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ;; ; ; ; ;The Piacenzian – Gelasian transition is a time of profound changes in the Earth's climatic regime, epitomized by the definitive establishment of large ice caps in the Northern Hemisphere and the beginning of the “ice ages” at ca. 2.6 Ma. This event is sharply documented in δ18O records globally by a prominent triplet of severe glacial events (MIS 100, 98 and 96) that approximate the base of the Gelasian Stage. We have reconstructed a multi-species planktic and benthic foraminiferal δ18O and δ13C record from the Monte San Nicola section (Sicily) across the Piacenzian/Gelasian boundary, with the purpose of better constraining in time the main marker criteria for recognition of the Gelasian GSSP (Global Boundary Stratotype Section and Point) and investigating in detail the paleoclimatic and paleoceanographic response of the central Mediterranean to the definitive onset of the Northern Hemisphere Glaciation. Our results confirm the reliability and usability of the criteria originally proposed for defining the Gelasian GSSP, and significantly improve their chronology and chronostratigraphic positioning. Beyond an obvious alternation of obliquity-driven glacial-interglacial cycles, our isotopic record unraveled a pervasive climate variability in the suborbital time domain, the origin of which is still ambiguous. Altogether data presented in this paper provide the first high resolution isotopic records shedding new light both on the stratigraphic and paleoclimatic evolution of the Central Mediterranean area at the beginning of the Northern Hemisphere Glaciation.165 45 - PublicationRestrictedOrbital variations in planktonic foraminifera assemblages from the Ionian Sea during the Middle Pleistocene Transition(2013)
; ; ; ; ; ; ;Incarbona, A.; Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Via Archirafi 22, 90134 Palermo, Italy ;Dinarès-Turell, J.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Di Stefano, E.; Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Via Archirafi 22, 90134 Palermo, Italy ;Ippolito, G.; Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Via Archirafi 22, 90134 Palermo, Italy ;Pelosi, N.; Consiglio Nazionale delle Ricerche, Istituto per l'Ambiente Marino Costiero, Calata Porto di Massa, Interno Porto di Napoli, 80133, Naples, Italy ;Sprovieri, R.; Università degli Studi di Palermo, Dipartimento di Scienze della Terra e del Mare, Via Archirafi 22, 90134 Palermo, Italy; ; ; ; ; The Middle Pleistocene Transition (1.2-0.7 Ma) is the most recent re-organization of the global climate system which includes variations in the frequency and amplitude of glacial/interglacial cycles, increased ice sheet volume, sea surface temperature cooling and a significant drop in the CO2 atmospheric levels. Here we present high-resolution planktonic foraminifera data (mean sampling resolution of about 780 years) from core LC10 recovered in the Ionian Sea (eastern Mediterranean), between 1.2 and 0.9 Ma. Selected taxa, among them G. ruber, T. quinqueloba and G. bulloides, show significant periodicities that can be associated to orbital cycles, mainly precession and obliquity. The planktonic foraminifera based paleoclimatic curve exhibits a cooling linear trend that can be associated to similar phenomena observed in the North Atlantic. On the other hand, we refer to the influence of the North African Monsoon the occurrence of two peaks of the low-salinity tolerant species G. quadrilobatus that fall in coincidence of sapropel layers. Finally, we discuss the distribution pattern of N. pachyderma sinistral coiling, with peaks up to about 20% between MIS 30 and 28, and compare it to middle-late Quaternary records of the Sicily Channel and western Mediterranean.195 32