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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 Florisphaera 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. • Highresolved calcareous nannofossil data from the Monte San Nicola 'Mandorlo' section. • Contrasting abundance patterns of placoliths vs. F. profunda point to surface productivity vs. deep nutricline. • Nutricline depth variation follows the 21kyr pace of precession and Northern Hemisphere summer insolation. • Suitability of the Monte San Nicola site for precise correlations at global, regional and local scale. [ABSTRACT FROM AUTHOR]

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. • A multispecies d18O and d13C record was reconstructed from Monte San Nicola (Sicily). • First isotopic record ever across the base Gelasian, ca. 2.7 to 2.5 Ma (MIS G5 to MIS 99). • Stratigraphic position of the Gelasian GSSP and its proxies was confirmed, their age improved. • Suborbital variability was found in glacial MIS 104 and 100, probably driven by the N. Atlantic. • Suborbital signals also occur in interglacial MIS G1, with ambiguous origin. [ABSTRACT FROM AUTHOR]

A new high-resolution pollen record, spanning the last five millennia, is presented from the Gulf of Gaeta (Tyrrhenian Sea, central Italy), with the aim of verifying if any vegetation change occurred in the central Mediterranean region in relation to specific well-known global and/or regional climate events, including the 4.2 ka event, the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA), and to detect possible vegetation changes related to still under-investigated climate signals, for example the so-called “Bond 2” cold event around 2.8 ka BP. The vegetation dynamics of the Gaeta record shows a recurrent pattern of forest increase and decline punctuating the mid- and late Holocene. When the timing of these patterns is compared with the climate proxy data available from the same core (planktonic foraminifera assemblages and oxygen stable isotope record) and with the NAO (North Atlantic Oscillation) index, it clearly appears that the main driver for the forest fluctuations is climate, which may even overshadow the effects of human activity. We have found a clear correspondence between phases with negative NAO index and forest declines. In particular, around 4200 cal BP, a drop in AP (Arboreal Pollen) confirms the clearance recorded in many sites in Italy south of 43°N. Around 2800 cal BP, a vegetation change towards open conditions is found at a time when the NAO index clearly shows negative values. Between 800 and 1000 AD, a remarkable forest decline, coeval with a decrease in the frequencies of both Castanea and Olea , matches a shift in the oxygen isotope record towards positive values, indicating cooler temperatures, and a negative NAO. Between 1400–1850 AD, in the time period chronologically corresponding to the LIA (Little Ice Age), the Gaeta record shows a clear decline of the forest cover, particularly evident after 1550 AD, once again in correspondence with negative NAO index. [ABSTRACT FROM AUTHOR]

Coccolithophores are an ecologically and biogeochemically important group of calcifying marine plankton, contributing globally to both the organic carbon pump and the carbonate counter pump. Understanding their distribution in today's ecosystems is crucial for both paleoenvironmental reconstruction and for predicting their fate under climate change and environmental pollution. Traditionally regarded as open ocean dwellers, more recent studies have highlighted their importance in coastal systems. Here we describe the coccolithophore community in the Catalan Sea (Northwestern Mediterranean), off the Ebro River Delta, based on an oceanographic survey conducted in autumn 2019. We identify three environmentally distinct regimes: mixed (mostly shallow), transition (upper photic layers offshore), and stratified deep waters (below 75 m). Total coccolithophore density is driven by Emiliania huxleyi and peaks in the mixed zone where nutrient concentrations are low, but nitrite concentrations are high. We propose that peak cell densities are partly explained by a switch from nitrate to nitrite usage similar to the behavior of diatoms. Species diversity peaks in deeper offshore waters due to vertical stratification. Helicosphaera carteri and Algirosphaera robusta benefit from E. huxleyi decrease both in coastal and offshore environment. • Coccolithophore distribution is described in the Catalan Sea, NW Mediterranean Sea. • E. huxleyi dominates the assemblage and peaks with high nitrite concentrations. • Species diversity peaks in deeper offshore waters due to vertical stratification. • H. carteri and A. robusta benefit from E. huxleyi decrease. [ABSTRACT FROM AUTHOR]

This work explores the significance of sedimentary proxies recorded within the Paleogene fine-grained detritus of the Adriatic foredeep (Northern Italy). Such sequences represent the only sedimentary record describing the source-to-sink system delivering detritus from the growing Alpine belt to the basin during the Eocene – Oligocene boundary. The combination of x-ray powder diffractometric, petrographic, SEM-EDS and biostratigraphic analyses on more than twenty samples from the Ternate-Travedona Formation, the Chiasso Formation, and the Villa Olmo Conglomerate allowed to identify the source areas of detritus and potential fluvial paleo-drainages, possibly ascribable to two different sectors of the Southalpine domain. Comparison between these results and the petrographic composition of the Cretaceous wedge in the same area opens to the possibility that Cenozoic drainages were inherited from more limited paleo-drainages developed during the end of the Mesozoic. Results of provenance analysis also gives new insights on how detrital compositions may vary in function of grain-size in tropical-subtropical environments. • Fine-grained sequences were studied through a multidisciplinary appoach • New provenance constrains morphogenic evolution of river catchments • Discussion on lack of syn-sedimentary volcaniclastic detritus • Discussion on the role of climate in signature variations [ABSTRACT FROM AUTHOR]

Abstract: The environment of the central Mediterranean Sea is investigated on the basis of high-resolution planktonic foraminifera and calcareous nannofossil data (mean sampling resolutions of about 80 and 160yr, respectively). MIS 5 is characterized by warm, oligotrophic and stratified waters, while coccolithophore communities developed a vertical zonation that, in today''s oceans, is typical of the low-latitude gyres. The temperate-subtropical configuration of planktonic foraminifera and calcareous nannofossil assemblages is repeatedly transformed into a temperate-subpolar one during the suborbital cooling episodes C25-C18. A comparison with European pollen sequences and North Atlantic cores over the interval between about 128 and 110 kyr BP is carried out. Records from this broad geographical area show a series of environmental changes that occurred at comparable times. However, the first cooling episodes were more severe at high-latitude (approximately north of 50°N), where an anticipated end of interglacial conditions can be ascribed. Variations in the rate of the Atlantic meridional overturning circulation and the strength of atmospheric circulation in the Northern Hemisphere are discussed as likely climatic forcing mechanisms. [Copyright &y& Elsevier]