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We report a new fossil-bearing locality from the “Chaotic Complex” units in the Northern Apennine Chain of the Emilia-Romagna Region (northern Italy). The material collected includes an articulated series of nine caudal vertebrae referable to a large-bodied ichthyosaur. Based on the nannofossil assemblage sampled from the matrix encasing the vertebrae, we refer the specimen to the early Aptian: this is the first accurate chronostratigraphic dating of a Cretaceous ichthyosaur from the Apennine Chain. The discovery of this new fossil-bearing locality is also significant because of the rather poor record of Aptian ichthyosaurs worldwide. Compared to the large majority of vertebrate remains from the “Chaotic Complex” units, usually represented by isolated or damaged skeletal elements, the specimen retains several vertebral elements in articulation and is associated to ichnological traces left by possibly saprophagous invertebrates, a taphonomic pattern which might indicate depositional conditions less destructive than those usually assumed for the genesis of the “Chaotic Complex’’ vertebrate fossils. The presence of both ichthyosaurs and thalattosuchians in the Aptian of Italy supports the persistence in the Western Tethys of the large-bodied pelagic reptile clades typical of the Middle and Late Jurassic along the first half of the Early Cretaceous.

A perfectly preserved left felid hemimandible has been found in fluvial deposits of the Po River near Cremona (Northern Italy). The fossil, found in allochthonous position within an alluvial bar, corresponding in morphology and size at the hemimandible of modern and fossil lions. The bone, in excellent conditions, is characterized by the presence of all the teeth and shows a slight erosion of the condyle and angular process indicating a very limited transport (rafting). Based on the comparison with a large dataset of morphometric measurements of cave lion and fossil leopard hemimandibles, the studied fossil is classified as a subadult female of the chronosubspecies Panthera spelaea intermedia. The mammalian fossil record from Po River consists predominantly of large herbivores Palaeoloxodon antiquus, Stephanorhinus kirchbergensis, Bison priscus, Megaloceros giganteus, Mammuthus primigenius, Alces alces, Cervus elaphus, some carnivores like Panthera cf. pardus, Crocuta crocuta, Ursus arctos, Canis lupus, Vulpes vulpes and primates such as Homo neanderthalensis and H. sapiens. The species composition indicates a mixing of different faunal assemblages from interglacial and glacial periods of the Late Pleistocene.

The Middle Ages represented a crucial period for the evolutionary history of wolves (Canis lupus), marked by both significant ecosystem changes, especially through the degradation of wooded landscapes and heavy persecution, that drove this species to a dramatic demographic decline. In Europe, informative and well-documented wolf remains from the Medieval Ages are exceptionally rare and are mostly represented by teeth and postcranial elements. In this study, we describe a well-preserved wolf cranium dated to ca. 967–1157 AD from the Po Valley (northern Italy). The specimen was analysed through a multidisciplinary approach including CT-based, ancient DNA, and palaeopathological analyses. Morphological and genetic data supported the assignment of this sample to Canis lupus species. CT-based analyses indicated a typical wolf-like morphology falling into the extant variability of the medium-sized subspecies C. lupus italicus, whereas palaeopathological analyses indicated a severe periodontitis. Phylogenetic analyses showed that the Po valley wolf had a unique and never described mtDNA control region haplotype, testifying variability in the ancient Italian wolf, which has now been lost. This study provides the first comprehensive description of a wolf from the Middle Ages, adding useful information for a deeper knowledge about population dynamics, variability, and diseases of this species.

The wooly rhinoceros (Coelodonta antiquitatis) and forest rhinoceros (Stephanorhinus kirchbergensis) were prominent representatives of the Middle and Late Pleistocene glacial and interglacial faunas of Eurasia. Their diet has traditionally been inferred on functional morphology of the dentition and skull. In rare cases, food remains are preserved in the fossas of the teeth or as gut content. New approaches to infer diet include the study of isotopes and mesowear. Here we apply all four methods to infer the diet of these emblematic rhinoceros' species and compare the food actually taken with the food available, as indicated by independent botanical data from the localities where the rhinoceros' fossils were found: Gorzów Wielkopolski (Eemian) and Starunia (Middle Vistulian) as well as analysis of literature data. We also made inferences on the season of death of these individuals. Our results indicate that the woolly rhino in both Europe and Asia (Siberia) was mainly a grazer, although at different times of the year and depending on the region its diet was also supplemented by leaves of shrubs and trees. According to the results of isotope studies, there were important individual variations. The data show a clear seasonal variation in the isotope composition of this rhino's diet. In contrast, Stephanorhinus kirchbergensis was a browser, though its diet included low-growing vegetation. Its habitat consisted of various types of forests, from riparian to deciduous and mixed forests, and open areas. The diet of this species consisted of selected items of vegetation, also including plants growing near both flowing and standing waters. The food remains from the fossae of the teeth indicated flexible browsing, confirming the previous interpretations based on functional morphology and stable isotopes. Long-term data from mesowear and microwear across a wider range of S. kirchbergensis fossils indicate a more mixed diet with a browsing component. The different diets of both of rhinoceros reflect not only the different habitats, but also climate changes that occurred during the Late Pleistocene., This research was supported by the grant No. 0201/2048/18 “Life and death of extinct rhino (Stephanorhinus sp.) from Western Poland: a multiproxy paleoenvironmental approach” finaced by the National Science Centre, Poland. Research by Elena M. Burkanova and Sergey V. Leshchisnkiy was funded by a grant from the Russian Science Foundation (RNF), Project No. 20-17-00033.

The Messinian salinity crisis (MSC) is an extreme event in Earth history during which a salt giant (>1×106 km3) accumulated on the Mediterranean seafloor within ~640 kyrs. The Messinian salt giant was formed about 6 million years ago when the restriction of water exchanges between the Atlantic Ocean and the Mediterranean Sea turned the Mediterranean into an enormous saline basin. After more than 40 years of research, the timing and the depositional environments of shallow ( The Levant Basin is the only deep Mediterranean basin where the entire Messinian section has been penetrated by wells tied to high resolution 3D seismic surveys. Here we present two studies challenging the desiccation paradigm dominating the MSC scientific literature for more than 40 years. The first study focuses on the nearly flat top erosion surface (TES) that truncates a basinward-tilted Messinian evaporitic succession. This truncation is commonly interpreted to be the result of subaerial erosion at the end of the MSC. However, based on high resolution seismic surveys and wireline logs, we show that (1) the TES is actually an intra-Messinian truncation surface (IMTS) located ~100 m below the Messinian-Zanclean boundary; (2) the topmost, post-truncation, Messinian unit is very different from the underlying salt deposits and consists mostly of shale, sand, and anhydrite showing typical 87Sr/86Sr values and fauna assemblages from stage 3; and (3) the flat IMTS is a dissolution surface related to significant dilution and stratification of the water column during the transition from stage 2 to stage 3. We suggest that dissolution occurred upslope where salt rocks at the seabed were exposed to the upper diluted brine, while downslope the salt rocks were preserved because submerged in the deeper halite-saturated layer. The model, which requires a stratified water column, is inconsistent with a complete desiccation of the eastern Mediterranean Sea. The second study focuses on the onset of the Messinian salinity crisis in the deep Eastern Mediterranean basin. Biostratigraphy and astronomical tuning of the Messinian pre-salt succession in the Levant Basin allows for the first time the reconstruction of a detailed chronology of the MSC events in deep setting and their correlation with marginal records that supports the CIESM (2008) 3-stage model. Our main conclusions are (1) MSC events were synchronous across marginal and deep basins, (2) MSC onset in deep basins occurred at 5.97 Ma, (3) only foraminifera-barren, evaporite-free shales accumulated in deep settings between 5.97 and 5.60 Ma, (4) deep evaporites (sulfate and halite) deposition started later, at 5.60 Ma. The wide synchrony of events implies inter-sub-basin connection during the whole salinity crisis and is not compatible with large sea-level fall that would have separated the eastern and western basins producing diachronic processes.

The Ross Ice Shelf is the Antarctic region that over the last deglaciation experienced the greatest change in areal ice cover. Today, cold, dense and saline water masses (brines) produced in the Ross Sea polynya, flow from the shelf to the deep ocean providing a significant contribution to the propelling of the global ocean circulation regulating the climate. In particular, the Hillary Canyon in the Eastern Ross Sea is the main conduit through which brines descend the slope to reach the deeper ocean and is thus one of the greatest regions of cold, dense water export in the world.A Contourite Depositional System (the ODYSSEA CDS) on the western flank of the Hillary Canyon is inferred to have been generated through several hundred-thousand years by along-slope, contour currents that transported and accumulated the sediments brought down the Hillary Canyon by means of brines. A multi-proxy investigation was conducted on the shallowest part of the ODYSSEA CDS depositional sequences, which we expect to contain i) the record of the brine formation, ii) the indication on contour current strength through time, and iii) their interplay and modulation associated to climate change.Six gravity cores, collected in both the proximal and distal area of the ODYSSEA CDS, were studied through multi-proxy analyses including sediment physical properties (texture, structures, water content, wet bulk density), compositional characteristics (XRF, geochemistry and detrital apatite, zircon, and rutile U-Pb on ice-rafted debris) (Lucchi et al., 2019; Neofitu et al., 2020) and microfossil content (planktonic and benthic foraminifera, calcareous nannofossils and diatoms). An age model has been reconstructed combining palaeomagnetic record, biostratigraphic content, tephrochronology and AMS radiocarbon dating on planktonic foraminifera tests.Inferred variations in dense water formation, contour current strength and ice sheet dynamics are discussed in the light of our data interpretation. Lucchi, R.G., Caburlotto, A., Miserocchi, S., Liu, Y., Morigi, C., Persico, D., Villa, G., Langone, L., Colizza, E., Macrì, P., Sagnotti, L., Conte, R., Rebesco, M., 2019. The depositional record of the Odyssea drift (Ross Sea, Antarctica). Geophysical Research Abstracts, Vol. 21, EGU2019-10409-1, 2019. EGU General Assembly, Vienna (Austria), 7–12, April, 2019 (POSTER).Neofitu, R., Mark, C., Rebesco, M., Lucchi, R.G., Douss, N., Morigi, C., Kelley, S., Daly, J.S., 2020. Tracking Late Quaternary ice sheet dynamics by multi-proxy detrital mineral U-Pb analysis: A case study from the Odyssea contourite, Ross Sea, Antarctica. Geophysical Research Abstracts. EGU General Assembly, Vienna (Austria), 3–8, May, 2020 (POSTER for session CL1.11).

We present a basin-wide correlation of the pre-evaporitic succession across the deep Levant basin, based on integrated bio- and cyclostratigraphy. The onset of Messinian salinity crisis (MSC) can be placed in all studied wells where foraminifers suddenly disappear and normal marine calcareous nannofossils are replaced by opportunistic assemblages. These changes mark the base of the Foraminifers Barren Interval (FBI), a 10s-of-m-thick (below seismic resolution), evaporite-free, shale unit that records the entire duration of the first stage. Moving towards the basin margin the FBI is progressively truncated on top by the Messinian erosional surface (MES), a regional-scale discontinuity sealed by a thin clastic evaporite units overlain by thick halite deposits. Our results confirm previous hypothesis suggesting that the crisis started in deep- as well as in shallow-water settings at 5.97 Ma and pointing to a synchronous onset of the MSC but diachronous deposition of evaporites. During stage 1 of the crisis, coeval with gypsum deposition in marginal basins, the salinity in deep basins progressively increased (with possible oxygen reduction) hindering the life of marine organisms. Then, at 5.60 Ma, when salinity in deep basins exceeded halite saturation, massive halite precipitation started, and a nearly 2-km-thick salt sequence accumulated in deep basins within a short period of 60 kyr. At that time (stage 2), sedimentation rate jumped by an order of magnitude reaching a few cm/yr. Similar sedimentation rates are inferred for the Realmonte salt mine (Sicily) and observed in the modern Dead Sea and artificial salinas.

The India-Asia collision led to the demise of the Tethys Ocean, and the subsequent uplift of the Qinghai-Tibet Plateau had a profound impact on Cenozoic topography, oceanography, and climate. However, collision ages vary depending on collision definition and methodology, with the cessation of marine deposition constraining the minimum/youngest collision age. The Enba and Zhaguo formations of the Qumiba Section (southern Tibet) represent the youngest marine strata in the eastern Tethys Ocean. Previous studies have suggested a middle-late Eocene or early Eocene closure time, however, our nannofossil data indicate an age of 53.67–52.64 Ma (nannofossil zone CNE3, which closely corresponds to Zone NP11). Nannofossil relative abundances can explain the early Eocene tectonic evolution of southern Tibet, with the increasing number of reworked Cretaceous nannofossils over time reflecting the degree of erosion of previously deposited sediments as the plateau uplift progressed. Our data suggest that Cretaceous and Paleocene calcareous nannofossils were an important sediment source to the Qumiba Section.

A slender right felid tibia has been found in river deposits of the Po River in the territory of Cremona (Northern Italy). The fossil, found in allochthonous position within an alluvial bar, shows an overall slenderness and subtlety, different shape of the shaft from lateral view, or less pronounced medial malleolus, corresponding in morphology and dimensions rather with tibiae of modern leopards than with shinbones of larger pantherines or feline cats. The bone is, however, faintly rounded (surface erosion of the edges in particular on the head of the tibia), indicating a limited transport (rafting). Based on that, it is determined as Panthera cf. pardus only. The whole mammalian fossil record from the site consists predominantly of large herbivores (Elephas (Palaeoloxodon) antiquus, “Dihoplus” (Stephanorhinus) kirchbergensis, Bison priscus, Megaloceros giganteus, Mammuthus primigenius, Alces alces, Cervus elaphus), whereas carnivores (Ursus arctos, Crocuta crocuta ssp., Canis lupus, Vulpes vulpes) are very rare and composed only by a few specimens. The species composition indicates probably a mixing of different faunal assemblages from warm (interglacial) and cold (glacial) periods of the Late Pleistocene.

After the formalization of the base of the Miocene in the Lemme-Carrosio section (Italy) at the base of Subchron C6Cn.2n, the calcareous plankton biostratigraphy was refined in several open ocean Deep Sea Drilling Project/Ocean Drilling Program sites. However, high-resolution quantitative biostratigraphic studies, integrating planktonic foraminifera and calcareous nannofossils, are still lacking for the time interval spanning the Oligocene–Miocene transition. Here, we present a reinvestigation of Deep Sea Drilling Project Hole 516F (Rio Grande Rise) and 4 oil wells drilled by Petrobras Brasileiro SA in the Campos Basin (SW Atlantic Ocean). We identified 12 planktonic foraminiferal and 18 calcareous nannofossil bioevents that have been integrated with an updated magnetostratigraphy of Hole 516F allowing the correlation with the GPTS and the identification of the Oligocene/Miocene boundary (base of Subchron C6Cn.2n) between the Top of Sphenolithus delphix and the Base of common Paragloborotalia kugleri. Furthermore, our results give new insights on the reliability of major calcareous plankton events across the Oligocene–Miocene transition: (a) the Sphenolithus ciperoensis Top, the S. delphix Base and Top, and the Sphenolithus cometa Base are reliable events at a global scale; (b) the Bases of Globoquadrina dehiscens and Sphenolithus disbelemnos > 4 μm are correlatable events only within the study sector of the SW Atlantic Ocean; and (c) the Globoturborotalita ciperoensis Top, Globoturborotalita angulisuturalis Top, and Sphenolithus procerus Base are diachronous. Finally, previously unreported biostratigraphic data, such as the distribution range of S. disbelemnos

New magnetobiostratigraphic data for the late Oligocene through early Miocene at Deep Sea Drilling Project (DSDP) Hole 516F provide a significantly revised age model, which permits reevaluation of developments that led to the Mi-1 glacial event at the Oligocene-Miocene boundary. Our new high-resolution paleomagnetic study, which is supported by quantitative calcareous nannofossil and planktonic foraminiferal analyses, significantly refines previous age models for Oligocene-Miocene sediments from DSDP Hole 516F, with ages that are systematically younger than those previously determined. In some parts of the Oligocene, the discrepancy with previous studies exceeds 450 kyr. Based on this new age model, we infer a progressive increase in sedimentation rate and paleoproductivity between circa 23.9 Ma and circa 22.9 Ma, with the highest rate coinciding with the Mi-1 glacial event at the Oligocene-Miocene boundary. This productivity increase would have resulted in higher rates of carbon burial and in turn a drawdown of atmospheric CO2. Immediately afterward, an abrupt decrease in sedimentation rate and paleoproductivity suggests that the Mi-1 deglaciation was associated with decreased carbon input into the ocean. Elevated sedimentation rates are also documented at ~24.5 Ma, coincident with the Oi2D glacioeustatic event. The presence of volcanic material within the sediments during these glacial events is interpreted to have resulted from redeposition of sediment scoured from nearby sites on the Rio Grande Rise due to transient variations in bottom water flow patterns.

The warm climate of the Miocene peaked during the middle Miocene Climatic Optimum (MMCO; 17–14.5 Ma). After the MMCO, global climate went through several short-lived cooling events: the Mi-events (Miocene isotope events). One of the more severe Mi-events is Mi-3, associated with East Antarctic Ice Sheet growth, species turnover in terrestrial and marine realms, Northern Hemisphere and mid-latitude aridification and Antarctic sea-surface temperature cooling. CO2 reconstructions, as well as the aforementioned observations, suggest that a drawdown of CO2 and/or changes in ocean circulation led to the changes surrounding Mi-3. A combination of eccentricity and obliquity amplitude modulation minima, favourable conditions for ice growth, has also been suggested as a possible triggering mechanism. However, an exact cause cannot be pinpointed yet. High-resolution records necessary to investigate the exact order of events surrounding Mi-3 and the possible role of orbital forcing, a very likely trigger, are sparse.Integrated Ocean Drilling Program (IODP) Leg 307 recovered such a high resolution record from the middle Miocene at the Porcupine Basin (offshore south-western Ireland). Well-preserved palynomorphs, mainly organic-walled dinoflagellate cysts, acritarchs and some pollen were extracted from Site U1318, and relative and absolute abundance changes were determined. Using dinocysts and calcareous nannoplankton the age model for the record was improved. Based on the palynology, the Mi-3a, Mi-3b and Mi-4 events were successfully identified and concomitant palaeoenvironmental change was observed. These events, although different in magnitude, can be associated with a decrease in sea-surface temperature, as well as with a likely fall in sea-level. Furthermore, possible palaeoenvironmental preferences of 5 dinocyst taxa were determined, based on observations from the record and multivariate statistics.

Reticulofenestra oamaruensis is well represented in Ocean Drilling Program (ODP) Sites 738, 748, 744 (Kerguelen Plateau) and 689 (Maud Rise) in the Southern Ocean. The specimens encountered in this study provide an ideal opportunity to study the intraspecific variability and to investigate the stratigraphic distribution of this species in the middle-late Eocene. The original description of this species covers a size range from 13.8 μm to 17 μm. Our biometric analyses and morphological investigations suggest to include smaller ( 17 μm) specimens in R. oamaruensis. Morphometric analyses allowed us to recognize an intraspecific trend characterized by an increase in size, ranging from small phenotypes (8 μm), at the base of the distribution range (35.83 Ma), to large phenotypes (> 14 μm) at the top of its stratigraphic range (33.9 Ma), coincident with the original description. The common presence of small specimens of R. oamaruensis at the beginning of the biostratigraphic range in the studied Southern Ocean call for a biostratigraphic extension of its range to an age (35.83 Ma) older than the previous findings, hereby extending the stratigraphic range of this species.

A high-resolution study of sediments from DSDP Leg 72 Site 516 provided the opportunity to reconstruct a detailed biostratigraphy for the late Oligocene - early Miocene time interval. The detailed taxonomic investigation of calcareous nannofossils, performed by a quantitative analysis, highlighted the presence of a species of Pontosphaera that does not show the morphologic features of any recognized species of this genus. This species, which was previously classified as Pontosphaera sp., is here described as Pontosphaera wallacei nov. sp.

Stratigraphic drilling from the McMurdo Ice Shelf in the 2006/2007 austral summer recovered a 1284.87 m sedimentary succession from beneath the sea floor. Key age data for the core include magnetic polarity stratigraphy for the entire succession, diatom biostratigraphy for the upper 600 m and 40Ar/39Ar ages for in-situ volcanic deposits as well as reworked volcanic clasts. A vertical seismic profile for the drill hole allows correlation between the drill hole and a regional seismic network and inference of age constraint by correlation with well‐dated regional volcanic events through direct recognition of interlayered volcanic deposits as well as by inference from flexural loading of pre‐existing strata. The combined age model implies relatively rapid (1 m/2–5 ky) accumulation of sediment punctuated by hiatuses, which account for approximately 50% of the record. Three of the longer hiatuses coincide with basin‐wide seismic reflectors and, along with two thick volcanic intervals, they subdivide the succession into seven chronostratigraphic intervals with characteristic facies: 1. The base of the cored succession (1275–1220 mbsf) comprises middle Miocene volcaniclastic sandstone dated at approx 13.5 Ma by several reworked volcanic clasts; 2. A late-Miocene sub-polar orbitally controlled glacial–interglacial succession (1220–760 mbsf) bounded by two unconformities correlated with basin‐wide reflectors associated with early development of the terror rift; 3. A late Miocene volcanigenic succession (760–596 mbsf) terminating with a ~1 my hiatus at 596.35 mbsf which spans the Miocene–Pliocene boundary and is not recognised in regional seismic data; 4. An early Pliocene obliquity-controlled alternating diamictite and diatomite glacial–interglacial succession (590–440 mbsf), separated from; 5. A late Pliocene obliquity-controlled alternating diamictite and diatomite glacial–interglacial succession (440–150 mbsf) by a 750 ky unconformity interpreted to represent a major sequence boundary at other locations; 6. An early Pleistocene interbedded volcanic, diamictite and diatomite succession (150–80 mbsf), and; 7. A late Pleistocene glacigene succession (80–0 mbsf) comprising diamictite dominated sedimentary cycles deposited in a polar environment.

ANDRILL Core AND-1B, recovered in the Western Ross Sea of Antarctica, has been examined in search of calcareous nannofossils. Exhaustive and detailed analyses of the interval from 86.61 to 98.99 mbsf revealed for the first time at an extreme southern high latitude (77.88° S) the presence of lower Pleistocene calcareous nannofossils, together with Tertiary and Upper Cretaceous reworked species. Other calcareous microfossils in the assemblage include, spicules of calciosponges and small foraminifers. The short normal magnetozone between 84.97 and 91.13 mbsf is correlated with the Jaramillo Subchron (C1r.1n) (Wilson et al., 2007). The presence of nannofossils in the biogenic interglacial sediments is consistent with an episode of warm surface waters and open-marine conditions during the Jaramillo subchron, at ~ 1 Ma, which corresponds with Marine Isotope Stage (MIS)-31 (Scherer et al., 2007; Naish et al., 2007). Climate proxies such as oxygen isotope stratigraphy and calcareous nannofossils at ODP Site 1165 (Pospichal, 2003; Villa et al., 2008) and the diatom assemblage in a shelly carbonate sequence at Cape Roberts 1 (Bohaty et al., 1998) also support a warming event during this time and suggest it extended around the Antarctic Continent. This in turn implies a total or partial collapse of the McMurdo Ice Shelf and a concurrent shift or temporary dissipation of the Polar Front (Antarctic Convergence) and Antarctic Divergence that currently serve as barriers to the influx of calcareous nannofossils to the margins of Antarctica.

Calcareous Nannofossils are widely utilized in biostratigraphic studies of Cenozoic sediments. In recent years large datasets have been acquired, and several bioevents showed to be unreliable when correlated over distant areas. New biostratigraphic investigations of middle Eocene-upper Oligocene deep-sea cores have highlighted problematic areas in the currently used calcareous nannofossil zonal schemes for the Southern Ocean. Quantitative analysis on sediments from seven ODP (Ocean Drilling Program) sites from this area, characterized by abundant, diverse, and moderately to well-preserved nannofloral assemblages, have enabled a revision of the existing zonation for the Southern Ocean, and the development of a high-resolution zonal scheme. Eleven zones and six subzones are introduced or emended to replace the ten zones and two subzones of the Wei and Wise (1990a) and Wei and Thierstein (1991) , with the identification of several new biohorizons. New age calibrations are provided improving regional correlations and evaluating the reliability of the identified events for supraregional correlations. Comparisons are made between the proposed zonation and the existing schemes, both on nannofossils from different geographic areas, and on foraminifers from southern high latitudes.

A major deterioration in global climate occurred through the Eocene–Oligocene time interval, characterized by long-term cooling in both terrestrial and marine environments. During this long-term cooling trend, however, recent studies have documented several short-lived warming and cooling phases. In order to further investigate high-latitude climate during these events, we developed a high-resolution calcareous nannofossil record from ODP Site 748 Hole B for the interval spanning the late middle Eocene to the late Oligocene (~ 42 to 26 Ma). The primary goals of this study were to construct a detailed biostratigraphic record and to use nannofossil assemblage variations to interpret short-term changes in surface-water temperature and nutrient conditions. The principal nannofossil assemblage variations are identified using a temperate-warm-water taxa index (Twwt), from which three warming and five cooling events are identified within the middle Eocene to the earliest Oligocene interval. Among these climatic trends, the cooling event at ~ 39 Ma (Cooling Event B) is recorded here for the first time. Variations in fine-fraction ?18O values at Site 748 are associated with changes in the Twwt index, supporting the idea that significant short-term variability in surface-water conditions occurred in the Kerguelen Plateau area during the middle and late Eocene. Furthermore, ODP Site 748 calcareous nannofossil paleoecology confirms the utility of these microfossils for biostratigraphic, paleoclimatic, and paleoceanographic reconstructions at Southern Ocean sites during the Paleogene.

Nannofossil data from ODP Site 711 (equatorial Indian Ocean) yield a set of consistent, reliable biohorizons that form the basis of a revised calcareous nannofossil biostratigraphy for the low-latitude Eocene-Oligocene. We discuss 31 biohorizons occurring over an 11 myr time interval which we correlate to previous magnetostratigraphic data. Calcareous nannofossils from the middle Eocene through the lower Oligocene of the studied section are characterized by moderately well preserved assemblages consisting largely of low latitude and cosmopolitan species. A significant nannofossil dissolution interval is evidenced at the middle Eocene Climatic Optimum (MECO). We document a significant increase in late Eocene nannoplankton exhibiting a eutrophic preference. Analysis of the assemblage suggests important changes in the equatorial oceanic regime just before the onset of the Eocene-Oligocene transition (EOT), that foreshadow the more dramatic climatic shift of the early Oligocene.

Palaeoecological changes in nannofossil assemblages in the Southern Ocean during Oligocene times are examined through high-resolution, quantitative analyses of samples from Ocean Drilling Program (ODP) Site 748 (Kerguelen Plateau). We quantitatively characterized the palaeoecological preference of groups of species and compared their general trends with those determined at Maud Rise (ODP Sites 690 and 689) (Persico, D., Villa, G., 2004. Eocene–Oligocene calcareous nannofossils from Maud Rise and Kerguelen Plateau (Antarctica): palaeoecological and palaeoceanographic implications. Marine Micropaleontology 52, 153–179). We then attempt a correlation between the main assemblage variation and sea-surface temperature (SST) changes in the Southern Ocean at this time. Relatively stable, cool conditions are interpreted to have persisted from earliest to late Oligocene times, when an increase in abundance of temperate-water taxa is recorded, both at Maud Rise and Kerguelen Plateau, before the Mi-1 event. This reveals a climatic event that probably involved both sites, and which is comparable to that indicated by the global oxygen isotope curve ([Miller, K.G., Wright, J.D., Fairbanks, R.G., 1991. Unlocking the Ice House: Oligocene–Miocene oxygen isotopes, eustasy, and margin erosion. Journal of Geophysical Research, 96, 6829–6848; Zachos, J., Pagani, M., Sloan, L., Thomas, E., Billups, K., 2001. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science, 292, 686–693.]). In the uppermost Oligocene at Site 689, the temperate-water taxa index ([temperate / temperate + cool] * 100) increases from 25.2 Ma. Similarly, at Site 748, the temperate-water taxa index indicates an increase in SST in the late Oligocene, from about 26.5 Ma, at the base of Chron C8n.2n, which is offset by about 1 m.y. between the two areas. The reason for this time difference can probably be found in the location of Site 748 with respect to Site 689, and in the palaeoceanographic setting, taking into account that Site 748 lies north of a deep water passage that separates Kerguelen Plateau from Antarctica, and north of the present day front of the Antarctic Circumpolar Current. The presence of warm-water taxa, exclusively at Site 748, corroborates this hypothesis.

The evolution of the Southern Ocean climate during the late Eocene–late Oligocene interval is examined through high-resolution, quantitative calcareous nannofossil analyses on samples from the Southern Ocean sections on Maud Rise and Kerguelen Plateau. We determined the abundance patterns of the counted species to clarify the biostratigraphy, which we correlated with high-resolution magnetostratigraphy [Roberts, A.P., Bicknell, S.J., Byatt, J., Bohaty, S.M., Florindo, F., Harwood, D.M., 2003a. Magnetostratigraphic calibration of Southern Ocean diatom datums from the Eocene–Oligocene of Kerguelen Plateau (Ocean Drilling Program Sites 744 and 748). In: Florindo, F., Cooper, A.K., O'Brien, P.A. (Eds.), Antarctic Cenozoic Palaeoenvironments: Geologic Record and Models. Palaeogeogr., Palaeoclimatol., Palaeoecol. 198 145–168; Florindo, F., Roberts, A.P., in press. Eocene–Oligocene magnetobiochronology of ODP Sites 689 and 690, Maud Rise, Weddell Sea, Antarctica. Geol. Soc. Am. Bull.], and used this data to interpret paleoceanographic changes through the late Eocene to late Oligocene. Percentage plots of the individual species, compared with R-mode principal component and cluster analysis results, allowed us to divide the assemblages into three groups: temperate-water taxa, cool-water taxa, and no temperature-affinity taxa. We attempt correlations between these paleoecological groups and the major sea-surface temperature (SST) variations with tectonic and paleoceanographic changes in the Southern Ocean. During the late Eocene, the nannofossil assemblage data reveal that there were several minor SST decreases (coolings) from 36 to 34 Ma, before the Eocene/Oligocene (E/O) boundary. A sharp cooling event, dated at 33.54 Ma (earliest Oligocene), occurred about 160 kyr after the E/O boundary, which is dated at 33.7 Ma. Relatively stable, cool conditions are interpreted to persist until the latest Oligocene, when an increase in abundance of temperate-water taxa, which corresponds to an antithetical decrease in abundance of cool-water indicators, is recorded. On the basis of our dating, the opening of the Drake Passage, allowing shallow-water circulation, began by 33.54 Ma at the latest, while the establishment of deep-water connections through the Tasmanian Gateway occurred at 33 Ma, as suggested by Exon et al. [Proc. ODP, Init. Rep. 189 (2001) 1].

During the Eocene-Oligocene transition, Earth cooled significantly from a greenhouse to an icehouse climate. Nannofossil assemblages from Southern Ocean sites enable evaluation of paleoceanographic changes and, hence, of the oceanic response to Antarctic ice sheet evolution during the Eocene and Oligocene. A combination of environmental factors such as sea surface temperature and nutrient availability is recorded by the nannofossil assemblages of and can be interpreted as responses to the following changes. A cooling trend, started in the Middle Eocene, was interrupted by warming during the Middle Eocene Climatic optimum and by short cooling episodes. The cooling episode at 39.6 Ma preceded a shift toward an interval that was dominated by oligotrophic nannofossil assemblages from ~39.1 to ~36.2 Ma. We suggest that oligotrophic conditions were associated with increased water mass stratification, low nutrient contents, and high efficiency of the oceanic biological pump that, in turn, promoted sequestration of carbon from surface waters, which favored cooling. After 36.2 Ma, we document a large synchronous surface water productivity turnover with a dominant eutrophic nannofossil assemblage that was accompanied by a pronounced increase in magnetotactic bacterial abundance. This turnover reflects a response of coccolithophorids to changed nutrient inputs that was likely related to partial deglaciation of a transient Antarctic ice sheet and/or to iron delivery to the sea surface. Eutrophic conditions were maintained throughout the Oligocene, which was characterized by a nannofossil assemblage shift toward cool conditions at the Eocene-Oligocene transition. Finally, a warm nannofossil assemblage in the Late Oligocene indicates a warming phase.

Lucchi, Renata G. ... et al.-- 18 pages, 9 figures, 2 tables, The depositional history of the Storfjorden and Kveithola trough-mouth fans (TMFs) in the northwestern Barents Sea has been investigated within two coordinated Spanish and Italian projects in the framework of the International Polar Year (IPY) Activity 367, NICE STREAMS. The investigation has been conducted using a multidisciplinary approach to the study of sediment cores positioned on high-resolution multibeam bathymetry and TOPAS/CHIRP sub-bottom profiles.Core correlation and the age model were based on 27 AMS 14C samples, rock magnetic parameters, lithofacies sequences, and the presence of marker beds including two oxidized layers marking the post Last Glacial Maximum (LGM) inception of deglaciation (OX-2) and the Younger Dryas cold climatic event (OX-1).Sediment facies analysis allowed the distinction of a number of depositional processes whose onset appears closely related to ice stream dynamics and oceanographic patterns in response to climate change. The glacigenic diamicton with low water content, high density, and high shear strength, deposited during glacial maxima, indicates ice streams grounded at the shelf edge. Massive release of IRD occurred at the inception of deglaciation in response to increased calving rates with possible outer ice streams lift off and collapse. The presence of a several-meter-thick sequence of interlaminated sediments deposited by subglacial outbursts of turbid meltwater (plumites) indicates rapid ice streams' melting and retreat. Crudely-layered and heavily-bioturbated sediments were deposited by contour currents under climatic/environmental conditions favorable to bioproductivity.The extreme sedimentation rate of 3.4cma-1 calculated for the plumites from the upper-slope area indicates a massive, nearly instantaneous (less than 150years), terrigenous input corresponding to an outstanding meltwater event. We propose these interlaminated sediments to represent the high-latitude marine record of MeltWater Pulse 1a (MWP-1a). Different bathymetric and oceanographic conditions controlled locally the mode of glacial retreat, resulting in different thickness of plumites on the upper continental slope of the Storfjorden and Kveithola TMFs. It is possible that the southern part of Storfjorden TMF received additional sediments from the deglaciation of the neighboring Kveithola ice stream. © 2013, This study was supported by the Spanish IPY projects SVAIS (POL2006-07390/CGL) and IPY-NICE STREAMS (CTM2009-06370-E/ANT), the Spanish project DEGLABAR (CTM2010-17386), and the Italian projects OGS-EGLACOM, and PNRA-MELTSTORM

This work presents the stratigraphic distribution of several species of calcareous nannofossil in the middle Eocene early–Oligocene from four Ocean Drilling Program (ODP) sites located between 60° and 65°S paleolatitude in the Southern Atlantic and Indian Oceans. Useful nannofossil datums that should facilitate construction of age-models and contribute to an integrated chronology for the upper Paleogene Southern Ocean sediments from ~ 42 to 33 Ma are summarized. The distribution patterns of calcareous nannofossils, studied by means of quantitative and semiquantitative methods, provide an improvement of the classical Southern Ocean biozonations, introducing new biostratigraphically useful biohorizons, and testing their reproducibility within and outside the region.

Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch ( approximately 5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming. Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, approximately 40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to approximately 3 degrees C warmer than today and atmospheric CO(2) concentration was as high as approximately 400 p.p.m.v. (refs 5, 6). The evidence is consistent with a new ice-sheet/ice-shelf model that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and air temperatures above freezing, suggesting an additional influence of surface melt under conditions of elevated CO(2).

The integrated calcareous plankton biostratigraphy (planktonic foraminifera and calcareous nannofossils) and an accurate fieldwork, allowed us the reconstruction of the sedimentary evolution of the Longano Formation (Orbulina Marls). In particular the correlation between the bioevents recognised in the Orbulina Marls sequence and those recorded in astronomically calibrated Middle Miocene sections, offered the possibility to date the passage from the shallow-water Cusano Formation to the deep-water deposits of the Longano Formation at about 13.21 Ma and the successive onset of terrigenous deposits of the Pietraroia Formation at 10.54 Ma. In addition, an high resolution study of the terrigenous sequence, showed that this sedimentary event is not abrupt but it is characterised by a progressive increase, bed by bed, of the siliciclastic fraction up to the deposition of the sandstones. The recognition in all the studied sections of the base of the first Acme (AB1) of Paragloborotalia siakensis dated at 13.21 Ma, just above the phosphate-rich interval (this interval marks the transition between Cusano and Longano Formations), proved that the transgression which led to the deposition of the Orbulina Marls was synchronous in all the south-eastern Matese Mountains., Rivista italiana di Paleontologia e Stratigrafia, Vol 111, No 1

The SEDANO Project recovered 19 gravity cores on sediment drifts from the Pacific continental margin of the Antarctic Peninsula [Camerlenghi et al. (1997a) High-resolution terrigenous sedimentary record of the sediment drifts on the Antarctic Peninsula Pacific margin. In: Ricci, C.A. (Ed.), The Antarctic region. Museo Nazionale dell’Antartide, Siena, pp. 705–710]. Fifteen cores were sampled with the aim of developing an integrated biostratigraphy and palaeoecology based on calcareous nannofossils, diatoms, planktonic and benthic foraminifera, framed in a depositional process reconstruction. Barren gray laminated and brown bioturbated hemipelagic sediments characterize glacial and interglacial cycles, respectively. Analyses from both intervals allow comparison between microfossil occurrence in glacial and interglacial cycles. The unit boundaries were drawn more accurately by means of the microfossil distribution. On the basis of micropalaeontological and sedimentological evidence, Interglacial Unit C is correlated to Oxygen Isotope Stage 5, thus dating the unit boundaries at 127 and 70 ka. Peaks in diatom abundance correlate well with interglacial units and indicate high productivity and an open ocean environment. A calcareous nannofossil cold-taxa association is present in most cores examined, and its consistent distribution within Interglacial Unit C indicates key environmental relationships. The occurrence of calcareous nannofossils has been related to temperature tolerance, sea-ice cover reduction, nutrient availability, and factors limiting primary productivity. Our results confirm that coccolithophorids occurred at southern high latitudes, in the western marginal basins of the Antarctic Peninsula, during short periods of the Late Quaternary. A foraminiferal assemblage, made up of sinistral Neogloboquadrina pachyderma and few benthics, occurs only in interglacial units. Correlation of microfossil occurrences with climatic cycles adds information on their palaeoecology and palaeoproductivity in the southern high latitudes.