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Framed into a robust stratigraphic context, multivariate analyses on the Holocene palaeobiological record (pollen, benthic foraminifers, ostracods) of the Po coastal plain (NE Italy) allowed the investigation of microtidal ecosystems variability and driving parameters along a 35-km-long land–sea transect. Millennial-scale ecosystem shifts are documented by coeval changes in the meiofauna, reflecting variations in organic matter–water depth (shallow-marine environments) and degree of confinement-salinity (back-barrier settings). In-phase shifts of vegetation communities track unsteady water-table levels and river dynamics in freshwater palustrine areas. Five environmental–ecological stages followed one another crossing four tipping points that mark changes in relative sea level (RSL), climate and/or fluvial regime. At the culmination of Mediterranean RSL rise, after the 8200 event, remarkable growth of peatlands took place in the Po estuary, while low accumulation rates typified the shelf. At the transgressive–regressive turnaround (~7000 cal a bp), the estuary turned into a delta plain with tidally influenced interdistributary embayments. River flow regime oscillations after the Climate Optimum (post-5000 cal a bp) favoured isolation of the bays and the development of brackish wetlands surrounded by wooded peatlands. The youngest threshold (~800 cal a bp), which led to the establishment of the modern delta, reflects a major avulsion of the Po River.

The 14 rooms of the Giovanni Capellini Museum of the University of Bologna house one of the most important fossil collections in Europe in a substantially unaltered layout of late 19th Century, which makes it a must-visit museum in Bologna. The Museum was the venue of the Second International Geological Congress in 1881 and here was also founded the Italian Geological Society. Recently, a permanent exhibition was set up to celebrate the Museum's unique micropaleontological legacy. The exhibition is housed in six large showcases at the ground floor and allows visitors a journey into the history of foraminiferal micropaleontology, from the discovery of the first microfossils, which took place a few miles from the Museum in the early 18th Century, to the first half of the 20th Century when micropaleontology reached a leading role in Earth Sciences.

Understanding Quaternary dynamics of delta-coastal plains across multiple glacial-interglacial cycles in the Milankovitch band (~100 kyrs) is crucial to achieve a robust evaluation of possible environmental response to future climate-change scenarios. In this work, we document the long-term bio-sedimentary record of core 204 S16 (~205 m long), which covers a wide portion of the post-MPR (Mid-Pleistocene Revolution) interval, taking advantage of the highly subsiding context of the SE Po Plain (NE Italy). Detailed facies characterization through an integrated sedimentological and meiofauna (benthic foraminifers and ostracods) approach allowed for the identification of a repetitive pattern of alluvial deposits alternating with four fossiliferous, paralic to shallow-marine units (Units 1–4). The transgressive surfaces identified at the base of these units mark major flooding events, forced by Holocene (Unit 4), Late Pleistocene (Unit 3) and Middle Pleistocene (Units 1, 2) interglacials. Distinct stratigraphic patterns typify the Middle Pleistocene interval, which includes coastal-marine (tidal inlet and bay) deposits. In contrast, lagoonal sediments record the maximum marine influence in the Late Pleistocene-Holocene succession. As a whole, the meiofauna tracks a regressive trend, with the deepest conditions recorded by the oldest Unit 1 (MIS 9/11 age?).

The definition of reference conditions has a major role for the understanding of the present-day and paleoecological quality status on transitional environments. The estuarine quality paradox and the paucity of unimpacted sites make the definition of reference conditions a challenging task. In this context, the integration of biological indicators with stratigraphic data is essential, as the vertical stacking pattern of facies composing the shallow subsurface of modern coastal plains reflects changes in physical-chemical parameters which, in turn, affect (paleo-)biotic communities.In the Po coastal plain (N Italy), the mid to late Holocene back-barrier succession of the Mezzano Lowland and the adjacent present-day Bellocchio Lagoon offer a unique example of pristine paralic system for comparing reference conditions defined in fossil and modern settings, respectively. Benthic foraminifers and ostracods from the Mezzano succession allowed us to investigate vertical (i.e., temporal) and lateral (i.e., spatial) changes in (paleo-)environmental conditions, in analogy to the lateral variations recorded at the Bellocchio Lagoon.Both sites present subtidal channel sands almost barren in autochthonous meiofauna and fine-grained lagoon sediments with abundant benthic foraminifers and ostracods mostly represented by euryhaline taxa recording the highest diversity. Intertidal muddy deposits are also recorded, including mud flat clays with abundant oligotypic assemblages dominated by highly-confined benthic foraminifers. In the present study, we demonstrate that changes in modern benthic foraminifer assemblages diversity and composition often interpreted as perturbations of ecological conditions in response to anthropogenic pressures also occur under natural state, as confirmed by paleoenvironmental conditions recorded by ostracods. This reflects the effects of authogenic processes at short time and geographic scales.

Despite increased application of subsurface datasets below the limits of seismic resolution, reconstructing near-surface deformation of shallow key stratigraphic markers beneath modern alluvial and coastal plains through sediment core analysis has received little attention. Highly resolved stratigraphy of Upper Pleistocene to Holocene (Marine Isotope Stage 5e to Marine Isotope Stage 1) alluvial, deltaic and coastal depositional systems across the southern Po Plain, down to 150 m depth, provides an unambiguous documentation on the deformation of previously flat-lying strata that goes back in time beyond the limits of morphological, historical and palaeoseismic records. Five prominent key horizons, accurately selected on the basis of their sedimentological characteristics and typified for their fossil content, were used as highly effective stratigraphic markers (M1 to M5) that can be tracked for tens of kilometres across the basin. A facies-controlled approach tied to a robust chronology (102 radiocarbon dates) reveals considerable deformation of laterally extensive nearshore (M1), continental (M2 and M3) and lagoon (M4 and M5) marker beds originally deposited in a horizontal position (M1, M4 and M5). The areas where antiformal geometries are best observed are remarkably coincident with the axes of buried ramp anticlines, across which new seismic images reveal substantially warped stratal geometries of Lower Pleistocene strata. The striking spatial coincidence of fold crests with the epicentres of historic and instrumental seismicity suggests that deformation of marker beds M1 to M5 might reflect, in part at least, syntectonically generated relief and, thus, active tectonism. Precise identification and lateral tracing of chronologically constrained stratigraphic markers in the(14)C time window through combined sedimentological and palaeoecological data may delineate late Quaternary subsurface stratigraphic architecture at an unprecedented level of detail, outlining cryptic stratal geometries at the sub-seismic scale. This approach is highly reproducible in tectonically active Quaternary depositional systems and can help to assess patterns of active deformation in the subsurface of modern alluvial and coastal plains worldwide., Sedimentology, 68 (1), ISSN:0037-0746, ISSN:1365-3091

To better explore the potential of Holocene subaqueous deltas as sedimentary archives, we quantitatively examined the benthic foraminiferal content of the muddy wedges belonging to three major Western Mediterranean deltas: Po Delta (N Adriatic Sea), Arno Delta (Ligurian Sea) and Rhone Delta (Gulf of Lions). The application of multivariate analyses (R-mode cluster, nMDS) on a regional dataset allowed defining six Mediterranean assemblages of taxa whose distribution, through time and space, is guided by the distance from the feeding mouths and by the balance of power between river and sea processes at the sea floor. At each site, the stratigraphic distribution of multivariate faunal data efficiently tracks the main changes in riverine fluxes and hydrodynamic levels, leading to a robust evaluation of (dis-)similarities in delta growth patterns. The dominant role of fluvial processes invariably emerges from the Po record, pointing to a river-dominated regime; whereas the foraminiferal fauna in the Arno and Rhone deltas indicates a wave-dominated regime with an intense redistribution of the river load by wind-driven currents throughout the Holocene. The distribution patterns of benthic foraminiferal assemblages in the multivariate space allow the identification of six biofacies, reflecting specific subaqueous environments that typify the Mediterranean shelves under different delta regimes: i) inner shelf; ii) deep-water mud belt; iii) shallow-water mud belt; iv) distal, river-dominated prodelta; v) distal, wave-dominated prodelta and vi) proximal prodelta. These biofacies can be a useful palaeoenvironmental tool for the interpretation of ancient, shallow-marine muddy successions belonging to the western Mediterranean stratigraphic record. The stratigraphic-based multivariate approach applied in this work can strongly support the analysis of subaqueous delta successions, developed even under different delta regimes and difficult to unravel from sedimentological features alone.

he lectotype of Ammonia beccarii (Linnaeus 1758) has been selected and described from Jacopo Bartolomeo Beccari's original samples in order to clarify the taxonomic status of this species.

Newly discovered sediment samples, manuscripts, and articles from the early eighteenth century, concerning the species we know today as Ammonia beccarii (Linnaeus), provide a good example of what is possibly the first micropaleontological analysis in the history of Earth Sciences. Thiswas performed by Jacopo Bartolomeo Beccari on fossil foraminifera in 1711, including detailed information in terms of: i) analysed material, ii) separation technique of the microfossils, iii) description of the assemblage and specifically of the dominant species (giving attention to coiling, sutures, internal structures, size, weight, and preservation state), iv) paleoenvironmental interpretation (supported by comparison with modern assemblages). The rigorous analytical approach and thorough interpretation, not only the accurate description of the observed fossil species, allow to assign to Beccari the distinction of "the founder of micropaleontology". The lectotype of Ammonia beccarii (Linnaeus 1758) is described from Beccari's original samples in order to clarify the taxonomic status of this species (Vaiani et al. 2019).

Integrated analyses of multiple groups of microfossils are frequently performed to unravel the palaeoenvironmental evolution of subsurface coastal successions, where the complex interaction among several palaeoecological factors can be detected with benthic assemblages. This work investigates the palaeoenvironmental resolution potential provided by benthic foraminifera and ostracoda within a Pleistocene lagoonal succession of the Romagna coastal plain (northern Italy). Quantitative approaches and statistical techniques have been applied to both groups in order to understand the main factors that controlled the composition of assemblages and compare the palaeoecological record provided by single fossil groups. The two faunal groups are characterized by the high dominance of opportunistic species (Ammonia tepida–Ammonia parkinsoniana and Cyprideis torosa); however, detailed palaeoecological information is inferred from less common taxa. Benthic foraminiferal assemblages are mainly determined by the frequencies of abnormal individuals and species related to high concentrations of organic matter, showing two assemblages: a stressed assemblage, consistent with a brackish-water environment subject to salinity and oxygen fluctuations, and an unstressed assemblage, which indicates more stable conditions. Despite the lower number of species, ostracoda show more significant differences in terms of species composition and ecological structure between their three assemblages, formed in response to a salinity gradient and indicative of inner, central, and outer lagoon conditions. The stratigraphic distribution of ostracod assemblages shows a general transgressive–regressive trend with minor fluctuations, whereas benthic foraminifera highlight the presence of a significant palaeoenvironmental stress. In this case, the higher abundance along the stratigraphic succession, the higher differentiation of the assemblages, and the well-defined relationship between taxa and ecological parameters determine Ostracoda as the most reliable fossil group for precise palaeoenvironmental reconstructions. Nevertheless, benthic foraminifera indicate palaeoenvironmental stress and can be used to refine the environmental interpretation in the presence of monospecific ostracod assemblages.

Though clinothem geometry represents a key control on fluid flow in reservoir modelling, tracing clinothem boundaries accurately is commonly limited by the lack of sufficiently precise outcrop or subsurface data. This study shows that in basin systems with strongly heterogeneous compositional signatures, the combination of bulk‐sediment geochemistry and benthic foraminiferal distribution can help identify clinothem architecture and generate realistic models of 3D deltaic upbuilding and evolution. Middle‐late Holocene deposits in the Po Delta area form an aggradational to progradational parasequence set that reveals the complex interaction of W–E Po Delta progradation, S‐directed longshore currents (from Alpine rivers) and Apennines rivers supply. Unique catchment lithologies (ophiolite rocks and dolostones) were used to delineate basin‐wide geochemical markers of sediment provenance (Cr and Mg) and to assess distinctive detrital signatures. The geochemical characterization of cored intervals across different components of the sediment routing system enabled a direct linkage between clinothem growth, transport pathways and provenance mixing to be established. On the other hand, abrupt microfaunal variations at clinothem boundaries were observed to reflect the palaeoenvironmental response to sharp changes in sediment flux and fluvial influence. This study documents the ability of an integrated geochemical and palaeoecological approach to delineate three distinct sources (Po, Alps and Apennines) that contributed to coastal progradation and to outline the otherwise lithologically cryptic geometries of clinothems that using conventional sedimentological methods it would be virtually impossible to restore.

The mid-late Holocene subsurface succession of the Po River plain records complex delta outbuilding under a predominantly autogenic control during the sea-level high stand phase. Chronologically constrained phases of the Po Delta evolution represent a solid base to test the response of microfossils to short time-scale delta dynamics. Benthic foraminifers and ostracods from the 21m-thick shallow-marine succession of core EM13 were quantitatively analysed and statistically compared to modern North Adriatic meiofaunal assemblages, in order to assess the main palaeoecological factors that controlled the composition of assemblages, and compare the palaeoenvironmental resolution provided by these two benthic groups. Benthic foraminifers from the lowermost shallow-marine succession indicate the transition from inner shelf to coastal conditions, marked by the gradual increase in Ammonia tepida and Ammonia parkinsoniana. Ostracods from the same stratigraphic interval are comparable to those nowadays recorded in shallow-marine settings affected by relatively low river flows. Chronologically in accordance with the development of cuspate deltas during the Roman Age, benthic foraminifers record the approach to coastal environments, subject to low fluvial inputs as evidenced by ostracods. The overlying deposits with high frequencies (ca. 50%) of A. tepida and A. parkinsoniana suggest the transition to a proximal prodelta, as confirmed by the similarity with modern assemblages at shallow depths, few km far from the river mouths. Upwards, the overwhelming dominance of the same taxa is indicative of extreme vicinity to river mouths. Within the same stratigraphic portion, ostracods indicate conditions similar to those nowadays present along the mid-Adriatic Italian coast, where the dominant action of longshore current distributes river-supplied material enriched in organic matter. Following one of the main avulsion events in the Po Delta history (XII century), the transition from wave- to fluvially dominated deltaic systems is marked by a great change in ostracod assemblages. Therefore, distinct palaeoecological information are provided by each fossil group: benthic foraminifers give indications about the distance from river mouths, whereas the dominant depositional regime is suggested by ostracods. Benthic foraminifers and ostracods are excellent palaeoenvironmental indicators in river-influenced shelves, but refined sub-environmental characterization can be achieved with their combined application only.

The key role of paralic environments as providers of ecosystem services, associated with their increasingly threatened state, led to the definition of international water management policies aimed to improve ecological quality status (EcoQs). Restoration actions rely on the definition of reference conditions, which is a particularly challenging task in naturally stressed transitional environments. In the present work, we apply the diversity index Exp(H&rsquo, bc) on benthic foraminifer assemblages from two anthropogenically unimpacted transitional to coastal Holocene sediment successions of the Po coastal plain, in order to assess past EcoQs (PaleoEcoQs). Ostracod ecological groups provided detailed insights on naturally stressful paleoenvironmental conditions. We show that &ldquo, poor&rdquo, to &ldquo, moderate&rdquo, PaleoEcoQs are recorded by biological indicators at reference conditions under fluctuations of chemical-physical parameters and organic matter enrichment. We emphasize the importance of a site-specific paleobiological approach, as significant differences in diversity occur even on a short spatial scale. This study illustrates that early to mid-Holocene sediment successions resulted to be appropriate for conservation paleobiological purposes, providing a high-resolution paleoecological record under the influence of the Holocene sea-level rise in analogy with the present-day global change.

Although general trends in transgressive to highstand sedimentary evolution of river-mouth coastlines are well-known, the details of the turnaround from retrogradational (typically estuarine) to aggradational–progradational (typically coastal/deltaic) stacking patterns are not fully resolved. This paper examines the middle to late Holocene eustatic highstand succession of the Po Delta: its stratigraphic architecture records a complex pattern of delta outbuilding and coastal progradation that followed eustatic stabilization, since around 7·7calkyrbp. Sedimentological, palaeoecological (benthic foraminifera, ostracods and molluscs) and compositional criteria were used to characterize depositional conditions and sediment-dispersal pathways within a radiocarbon-dated chronological framework. A three-stage progradation history was reconstructed. First, as soon as eustasy stabilized (7·7 to 7·0calkyrbp), rapid bay-head delta progradation (ca 5myear−1), fed mostly by the Po River, took place in a mixed, freshwater and brackish estuarine environment. Second, a dominantly aggradational parasequence set of beach-barrier deposits in the lower highstand systems tract (7·0 to 2·0calkyrbp) records the development of a shallow, wave-dominated coastal system fed alongshore, with elongated, modestly crescent beaches (ca 2·5myear−1). Third, in the last 2000years, the development of faster accreting and more rapidly prograding (up to ca 15myear−1) Po delta lobes occurred into 30m deep waters (upper highstand systems tract). This study documents the close correspondence of sediment character with stratal distribution patterns within the highstand systems tract. Remarkable changes in sediment characteristics, palaeoenvironments and direction of sediment transport occur across a surface named the ‘A–P surface’. This surface demarcates a major shift from dominantly aggradational (lower highstand systems tract) to fully progradational (upper highstand systems tract) parasequence stacking. In the Po system, this surface also reflects evolution from a wave-dominated to river-dominated deltaic system. Identifying the A–P surface through detailed palaeoecological and compositional data can help guide interpretation of highstand systems tracts in the rock record, especially where facies assemblages and their characteristic geometries are difficult to discern from physical sedimentary structures alone.

The detailed stratigraphic frame of the late Quaternary Po Delta deposits represents an ideal setting to test the response of microfossil assemblages to short-time phases of delta evolution, strictly constrained in time and space. Benthic foraminiferal studies within the Po Delta subsurface succession have been extensively performed in the last years, whereas less attention has been paid to ostracods. Holocene benthic foraminiferal and ostracod assemblages were determined in the 21m-thick shallow-marine deposits of core EM13. According to radiocarbon dates, the lower part of this fine-grained succession was formed during the last stages of transgression and the following high-stand phase, when a series of cuspate deltas developed in the study area. In contrast, the upper interval accumulated after the Ficarolo avulsion (mid XII Century AD), which determined the rapid outbuilding of the supply-dominated Po Delta. Here we test the ostracod ability to detect these evolutionary phases, possibly recorded as palaeoenvironmental changes. High concentration of valves and high species richness are recorded in the lowermost part of the succession, where ostracod assemblages include abundant Semicytherura spp. and Loxoconcha spp, indicative of a shallow-marine environment with low fluvial influence. The overlying sediments include scarce ostracods mainly represented by Pontocythere turbida, with lower frequencies of Palmoconcha turbida. Such low-diversity assemblage, dominated by opportunistic species, shows the transition to more stressed environmental conditions, in accordance with a prodelta environment. Species turnover is also recorded in the uppermost part of the succession, where Leptocythere ramosa becomes strongly dominant. Its tolerance to salinity variations and organic matter input indicates a very shallow and proximal prodelta with high fluvial influence. Scattered, mainly juvenile, valves of Cyprideis torosa are encountered through the entire sediment succession and suggest transport from coastal brackish-water environments due to the fluvial input. The superposition of these ostracod assemblages reflects small-scale palaeoenvironmental variations within a shallow prodelta environment, related to different phases of activity of the Po Delta. The comparison with foraminiferal assemblages reinforces the palaeoenvironmental interpretation and documents the combined analysis of benthic foraminifers and ostracods as a high-resolution proxy to reconstruct delta dynamics.

Integrating analysis of the benthic palaeoecological record with multivariate ordination techniques represents a powerful synergy able to provide an improved characterization of coastal depositional facies in a sequence stratigraphical perspective. Through quantitative analysis of benthic foraminifer, ostracod and mollusc associations from the postglacial succession of Core M3 (Arno coastal plain, Tuscany, Italy), and application of detrended correspondence analysis (DCA) to the mollusc sub-data set, we offer a refined picture of stratigraphical variations in faunal content from a paralic depositional setting, and reconstruct the palaeoenvironmental gradients that account for such variations. Despite distinct ecological behaviours, and taphonomic and sedimentological constraints, a strong ecological control on meio- and macrofaunal biofacies and taxa turnover is documented across the study succession. Amongst all possible mechanisms that may play a role in shaping' fossil distribution, the ecological signal driven by salinity represents the most prominent factor controlling the composition of fossil associations in the cored succession. Molluscs can even provide outstanding quantitative estimates of palaeosalinity along the sampled core. When plotted stratigraphically, the three fossil sub-data sets show consistent patterns of vertical evolution that enable prompt identification of the key surfaces for sequence stratigraphical interpretation in otherwise lithologically indistinguishable deposits. The concomitant maximum richness of species with strong marine affinity, paralleled by the highest DCA salinity estimates, allows recognition of the maximum flooding zone, dated to approximate to 7.7 cal. ka BP, within a homogeneous succession of outer lagoon clays. These clays are sandwiched between early transgressive, swamp to inner lagoon deposits and overlying prograding coastal-alluvial plain facies. (Less)

This study investigates Ionian Sea seismo-turbidite (ST) deposits that we interpret to be triggered by major historic earthquakes and tsunamis in the Calabrian Arc. ST beds can be correlated with the AD 1908 Mw 7.24 Messina, AD 1693 Mw 7.41 Catania, and AD 1169 Mw 6.6 Eastern Sicily earthquakes while two previously unknown turbidites might have been generated by the AD 1818 Mw 6.23 Catania and AD 1542 Mw 6.77 Siracusa earthquakes. Textural, micropaleontological, geochemical and mineralogical signatures of STs reveal cyclic patterns of STa, STb, STc and STd sedimentary units for each earthquake with an associated tsunami. The STa unit contains multiple ST stacks with different mineralogy, geochemistry foraminiferal assemblages and sedimentary structures that are deposited from synchronous multiple slope failures and turbidity currents. The STb homogenite graded mud unit overlying the STa unit is deposited by the waning flows of the multiple turbidity currents that are trapped in the Ionian Sea confined basin. The STc laminated and marine-sourced unit results from seiching of the confined water mass that appears to be generated by earthquake ruptures combined with tsunami waves. The STd unit is a tsunamite cap deposited by the slow settling suspension cloud created by tsunami wave backwash erosion of the shoreline and continental shelf. This tsunami process interpretation is based on the textural gradation of the upper unit and a more continental source of the tsunamite cap which includes C/N > 10 and the presence of inner shelf foraminifera with a lack of abyssal species. This interpretation is in agreement with the lack of a tsunamite cap for the turbidite likely linked to the AD 1542 historic earthquake that is not associated with a tsunami. The new sedimentologic criteria identifies the final seiche and tsunamite cap deposits of STs and provides a model that can now be tested in other locations to better understand the different depositional processes of seismo-turbidites in confined basins.

Detailed benthic foraminiferal analyses performed on the Holocene subsurface deposits of modern Po Delta evidenced a complex palaeogeographic evolution. Hierarchical R- and Q-mode cluster analyses allowed to distinguish four assemblages indicative of different marine environments and sub-environments. Temporal and spatial distribution patterns of benthic foraminifers reflect changes in Po River discharge during delta evolution. The capability of foraminiferal assemblages to track nutrients and sediment supply oscillations permitted to recognize four main evolutionary phases (A–D), which took place after the maximum marine transgression (ca. 5500 cal yr BP). Prodelta and delta front deposits are accumulated in the western part of the study area between the first stages of progradation and the late Middle Ages (ca. 10th century AD); these are paralleled, in a more distal position, by open-marine sedimentation, replaced upward by prodelta sediments (phases A and B). Owing to the combined effect of a major avulsion (Rotta di Ficarolo) and the Adriatic circulation patterns, an organic-rich zone developed in the eastern part of the present Po Delta at the transition to the Modern Age (phase C), around 600 cal yr BP. For the fist time a fossil mud-belt, although its marginal fringe, along with its peculiar microfossil content (Nonionella turgida assemblage), is recorded beneath a modern delta plain. During the recent past an outstanding rate of sedimentation affected the Po Delta, as clearly evidenced by the deposition of 14 meters fine-grained prodelta sediments between 600 and 380 cal yr BP. Prodelta deposits were finally replaced by delta front sands after the Porto Viro cut (ca. 350 cal yr BP), which marked the onset of Modern Delta (phase D).

Integrated sedimentological and micropaleontological study of 16 cores and 137 piezocone penetration tests, approximately 40 m deep, in the Comacchio area enables the documentation of the depositional history of southeastern Po Plain in the last 30 ka, in response to fluctuating sea-level. Sedimentation within an alluvial plain was the dominant feature across the entire study area during the pronounced sea-level fall which culminated in the last glacial maximum. Thin lowstand fluvial sediments form the lower part of a shallow incised valley identified above the last glacial maximum unconformity, whereas a characteristic paleosol separates the last glacial alluvial plain deposits from the overlying post-glacial deposits in the interfluves. Transgressive and highstand deposits show a well developed stacking pattern of retrogradational (coastal-plain and estuarine) and progradational (deltaic) facies. Detailed reconstruction of transgressive paleogeography shows evolutionary features which can be useful for refined interpretation of coeval and ancient analogs. At relatively early stages of transgression (10.5-9 ka BP) sedimentation in a coastal plain was restricted to the incised valley, whereas non-deposition and pedogenesis took place on the interfluves. With rising sea-level (9-6 ka BP) a wave-dominated, barred estuary developed in coincidence of the former topographic low. At peak transgression, after filling up of the estuarine systems with coastal, behind-barrier sediments, wide areas outside the valleys were flooded, aggradation extended onto the interfluve unconformity, and a shallow-marine depositional environment developed across most of the study area. The depositional history during the subsequent highstand phase was dominated by progradation of the early Po River delta, and reflects the complex interplay between high-frequency sea-level fluctuations, climate, subsidence, and autocyclic processes (distributary channel avulsion and delta lobe abandonment).

The analysis of fruit and seed assemblages in Pliocene and Early Pleistocene successions of the southern border of the Po Plain provides an interesting record of the terrestrial palaeoflora, which complements the information provided by the extensive pollen records available in this area. The 14 carpoflora-bearing layers studied here, spanning from 5.1 to 0.9 Ma, have been inserted in a definite stratigraphic framework, locally with a precision of ca. 100 ka. The input of the new data into the CENOFITA database showed that the fossil record of several species was often limited to one to three chronostratigraphic stages of the Pliocene (Zanclean, Piacenzian) and Early Pleistocene (Gelasian, Calabrian). A general analysis of the northern-Italian fossil record of such species allowed us to improve the distribution chart of carpological taxa in the Pliocene and Early Pleistocene. In this new chart, the carpological species were clustered in six groups of species with similar chronologic distributions. We suggest that the analysis of such groups, in undated or poorly dated carpological assemblages, would be useful for their biochronological interpretation: the Zanclean floras can be distinguished by the Piacenzian ones in case of occurrence of Group 1 species, whereas the simultaneous occurrence of several species of Groups 2 and 3, without species of Groups 1 and 5, could be used to suggest a Piacenzian affinity for undated assemblages. The occurrence of several species of Groups 5 and 6, without species of Groups 1–3, may just point to a generic Gelasian or Calabrian affinity. The palaeoclimatic characterization of the individual species, but also of the plant assemblages, suggests that a temperature decrease is one of the causes of the palaeofloral changes, in fact the most apparent events are represented by the disappearance of thermophilous species. The appearance of new species in the studied fossil record is mostly due to the establishment of favourable local environmental conditions, rather than to evolutionary events. However, the occurrence, in chronologically well-constrained layers, of fruits and seeds of a few plant genera with a proven late Cenozoic phylogenetic differentiation (e.g. Carex, Hypericum, Thymelaea) provides important support for the dating of species divergence times.

The Quaternary deposits of the Lamone River Valley in the Northern Apennines are mainly composed of marine clays and sands. Micropaleontological investigations allow the reconstruction of the paleoenvironmental evolution of that succession by recognition of 13 foraminifer and ostracod biofacies diagnostic of upper slope to deltaic environments. 87Sr/86Sr measurements were performed in well‐preserved fossils throughout most of the recognized biofacies. These are compared with the strontium (Sr) isotopic ratios of Pleistocene seawater. Samples collected within biofacies characteristic of slope to shallow marine environments, without significant riverine influence, provide Sr isotope ratios consistent with Pleistocene seawater. In contrast, fossils from shallow marine deposits of a river‐influenced zone may exhibit Sr isotope ratios lower than Pleistocene seawater. These anomalous ratios may be due to dilution by low‐87Sr/86Sr fluvial waters from the Lamone River that largely drain Tertiary sediment...

Sequence stratigraphic concepts can provide a powerful tool for understanding the tectono-sedimentary evolution of areas extending across different tectonic domains. An example is provided by the upper Serravallian strata of the northern Apennines, where a sedimentological and biostratigraphic study allows a sequence boundary to be traced across the foredeep and piggy-back basin successions. Turbidite sedimentation of predominantly alpine and subordinate apenninic provenance occurred in the apenninic foreland basin throughout the middle Miocene. Deep-water sedimentation in the foredeep was laterally associated with deposition in shelf to slope environments in the piggy-back basins. In the piggy-back basin succession, the upper Serravallian sequence boundary is a laterally extensive unconformity within homogeneous marly deposits. This unconfonnity is laterally correlative with the base of lenticular turbidite bodies. A stratigraphic lacuna affecting Zone N14 characterizes the marginal areas, where glaucony-rich deposits assigned to Zone N15 unconformably overlie marls displaying association of Zone N13. In the depocentres, where no significant stratigraphic gap has been detected, the sequence boundary is narrowly constrained to lowermost Zone N14. The upper Serravallian unconformity of the piggy-back basins succession is correlative with time-equivalent features in two distinct parts (inner basin and outer basin) of the foredeep. In the inner basin the sequence boundary separates basin margin turbidites from overlying slope hemipelagites. In a more external position (outer basin) the sequence boundary is the base of a characteristic mega turbidite of apenninic provenance (Turrito layer). In other sectors of the outer basin, where turbidite sedimentation was entirely of alpine provenance, the sequence boundary has no clear physical expression. The observed facies distribution in the study area suggests that an important thrusting event affected the northern Apennines in the late Serravallian, resulting in submarine channel incision and nondeposition in the piggy-back basins. Compressional activity in the foredeep was responsible for the closure of the inner basin and subsequent shifting of turbidite sedimentation in the outer basin. Slope instability led to widespread remobilization of previously deposited turbidites, triggering turbidite events of huge volume. The different characteristics of the sequence boundary in the various parts of the foredeep constitute an example of differential response of a multisourced supply system to tectonic deformation.

Metaxytherium subapenninum (Bruno, 1839) Fondi and Pacini, 1974 was a halitheriine dugongid distributed along the northwestern coasts of the Mediterranean Basin during the early and middle Pliocene. It represents the latest sirenian species of the Mediterranean Basin, the latest Metaxytherium species in the world and also the latest species belonging to the paraphyletic subfamily Halitheriinae. We review M. subapenninum in the light of new discoveries, including its stratigraphic and geographic distribution, osteology, paleoecology, and relationships. M. subapenninum represents a more derived stage of evolution in comparison with the earlier Metaxytherium species. It is characterized in particular by an increase in body size, an increase in tusk size, and a dorsal broadening of the nasal process of the premaxilla. Its variation in tusk size does not represent sexual dimorphism as in the modern Dugong, but instead progressive intraspecific evolution of larger tusks as a feeding adaptation convergent on that of derived dugongines. It was a relict species limited to the Mediterranean Basin, and responded to long-term climatic cooling by an increase in body size and by an increase in tusk size and enlargement of the nasal process of the premaxilla in order to obtain a more nutritious diet richer in rhizomes.

A new partial delphinid skeleton (Cetacea, Odontoceti), from Pliocene sediments of Tuscany (Italy) consists of a fragmentary skull, ear bones, mandible, some vertebrae and rib fragments. The specimen is related to the Pliocene “Stenella” giulii, a species known from four specimens collected in the Pisa hills in the second half of 19th Century. “Stenella” giulii is here referred to the new genus Etruridelphis. Differences between Etruridelphis and all the extant Stenella spp. include: i) larger size of skull ii) wider and flatter premaxillae on the rostrum iii) narrower superior process of the periotic and iv) lower processus muscularis of the malleus. The dolphin is from a 25 m thick section for which foraminifera indicate an Early Pliocene outer shelf or upper slope environment (slightly before 3.98 Ma). The dolphin horizon, 13 meters above the base of the section produces Globorotalia margaritae and G. puncticulata, indicating the MPl 3 zone (Zanclean). Previous biostratigraphic analyses on other Etruridelphis specimens confirm that E. giulii is Early and Middle Pliocene in age.

Despite abundant geologic literature about the Po coastal plain, stratigraphic architecture beneath modern Po River Delta is virtually unknown. In this paper, combined sedimentological, micropalaeontological and geochemical investigations of three continuous cores (cores 1 to 3), about 40 m thick, enable for the first time the detailed reconstruction of subsurface stratigraphy in the Po River Delta area, along with its late Quaternary palaeoenvironmental evolution. Lowstand deposits, formed during the Last Glacial Maximum, are expressed as a fining-upward succession of fluvial-channel and related overbank deposits, capped by a stiff, overconsolidated horizon. Above this unconformable surface, the lower post-glacial succession (transgressive systems tract or TST) is less than 7 m thick and includes a deepening-upward succession of back-barrier, shoreface and inner-shelf deposits. On the other hand, the overlying highstand systems tract is considerably thicker (up to 27 m) and comprises the bulk of recent delta progradation ( i.e. , vertically stacked prodelta, delta front and delta-plain deposits). Stratigraphic correlations within early transgressive, back-barrier deposits show vertically stacked, thin shallowing-upward successions, reflecting an internal subdivision of TST into small-scale parasequences. The homogeneous shallow-marine clay that accumulated at the turnaround from transgressive to highstand conditions can be palaeontologically differentiated into two packages ( Miliolidae -dominated and Ammonia/Cribroelphidium -dominated), reflecting open-marine and river-influenced conditions, respectively. Timing of maximum marine ingression (maximum flooding surface-MFS) is recorded within the open-marine clays at about 5500 calibrated yr BP by minor changes in microfauna. Geochemical characterization of Core 1 testifies that distinct changes in sediment provenance accompanied the palaeoenvironmental evolution of the study area under changing relative sea-level conditions. At lowstand times, the study area was an alluvial plain under the influence of Adige River, as suggested by comparatively high Ba/Al values within pre-Holocene fluvial deposits. Increasing upward values of Cr/Al 2 O 3 and Ni/Mg within TST suggest an increasing sediment provenance from the Po River during early stages of transgression, via the longshore drift. The onset of modern-age Po Delta in the study area is precisely identified in Core 1 at 25.10 m depth, and has a distinctive, double signature. In terms of microfaunal assemblages, Po River sediments are clearly marked by the development of a characteristic foraminiferal association dominated by the opportunistic species Nonionella turgida , a taxon typically abundant in the marginal zone of present northern Adriatic Sea mud-belt. Po River deposits are also fingerprinted by a peculiar geochemical composition, corresponding to maximum Cr and Ni concentrations.

A cyclic vertical succession of alluvial, littoral, and shallow-marine deposits is identified within two continuously cored boreholes (187-S1 and 204-S15) drilled to ~180 m beneath the present Po coastal plain, in northern Italy. Integrated sedimentologic, micropaleontologic (benthic foraminifers and ostracods), and geochemical studies allow the reconstruction of the paleogeographic evolution of the study area during the late Quaternary, with a special emphasis on major changes in provenance and sediment dispersal patterns. Transgressive surfaces appear as the most readily identifiable stratigraphic features in the two cores, allowing identification of a series of transgressive-regressive sequences. The transgressive surfaces mark the onset of coastal to shallow-marine conditions, followed by delta and strand plain progradation and the reestablishment of continental environments. This cyclic pattern of facies is paralleled by distinctive cyclic variations in chemical composition of sediments, reflecting a systematic increase in Ni/Al within lower transgressive deposits, followed by a marked decrease in the overlying alluvial plain sediments. At relatively northern locations (core 187- S1), the maximum flooding surfaces identified within shallow-marine deposits on the basis of subtle, but consistent changes in microfaunal assemblages are characterized by anomalously high Mg/Al values. The abrupt peaks in Ni/Al recorded at the transgressive surfaces are interpreted to reflect enrichments in mafic-ultramafic detritus, probably derived from the western Alps and the northwestern Apennines and supplied by the Po River to the coastal areas. These variations took place at the onset of brackish and littoral conditions, when direct connection with the sea favored sediment dispersal from the Po River mouth to lagoonal and coastal environments via the littoral drift. High Mg/Al values within open-marine deposits at the maximum flooding surfaces likely reflect an increasing contribution from eastern Alpine (dolomite-rich) sources at time of maximum shoreline migration. The recurrent changes in geochemical composition recorded across the transgressive surfaces fully support the stratigraphic subdivision of late Quaternary deposits of the Po Basin into transgressive-regressive sequences, rather than depositional sequences. The sequence-bounding unconformities do not display distinctive geochemical signatures.

Accumulation of continental, deltaic and shallow-marine sediments in the Po River coastal plain preserves a record of the Late Quaternary sea-level changes and shoreline migrations. The palaeoenvironmental evolution of this area and the changes in composition and provenance of sediments have been investigated through integrated sedimentological, micropalaeontological (mainly foraminifers) and geochemical analyses of core S1, from the southern part of the Po River delta, within a chronological framework supported by radiocarbon dating and correlations with adjacent core sequences. Eleven lithofacies, grouped into five facies associations, and four palaeontological assemblages provide the basis to define the palaeoenvironmental reconstruction of this succession consisting, from the base to the top, of: (i) continental sediments accumulated during the Late Pleistocene; (ii) back-barrier sediments marking the onset of Holocene sea-level rise; (iii) transgressive sands deposited during the rapid landward migration of a barrier-lagoon system; (iv) shallow-marine and prodelta sediments with faunal associations indicating a gradual approach to the Po River mouth; and (v) sub-recent delta front sands that form a considerable portion of the present coastal plain. Bulk chemical composition of sediments shows remarkable relationships with palaeoenvironments and locally improves facies characterizations. For example, they reveal carbonate leaching that emphasizes the occurrence of palaeosols in continental deposits or record enrichments in loss on ignition, S and Br, diagnostic of organic-rich layers in back-shore sediments. Selected geochemical elements (e.g. Mg and Ni) are particularly effective for the recognition of sediment provenances from the three main source areas observed in the subsurface deposits of the Po River coastal plain (e.g. Apenninic rivers, North Adriatic rivers and Po River). An Apenninic provenance is observed in continental and back-barrier sediments. A North Adriatic provenance characterizes the transgressive sands and the shallow-marine deposits; a significant Po River provenance is recorded in sediments related to the onset of the prodelta environment, confirmed by foraminiferal assemblages indicating remarkable increase in fluvial influxes. Copyright © 2006 John Wiley & Sons, Ltd.

Integrated sedimentological and micropalaeontological (foraminifers, ostracods, pollen) analyses of eight continuously cored boreholes, up to 140 m deep, reveal the depositional history and the palaeoclimatic evolution of southeastern Po Plain (northern Italy) over the last 150 ky. Age assignments are supported by the chronostratigraphic sequence framework calibrated by radiocarbon and pollen data, allowing detailed correlation with the oxygen-isotope record. Facies analysis (including identification of 12 distinct microfossils associations) and detailed stratigraphic correlations across several tens of km document a cyclic sedimentation pattern (including continental, coastal and shallow-marine deposits), which defines two transgressive–regressive sequences, deposited over the last two interglacial–glacial cycles. Two prominent stratigraphic markers, corresponding to wedge-shaped coastal sand bodies, are recorded between 0–30 and 100–125 m core depths. These sedimentary bodies were deposited during the two major transgressive pulsations and subsequent sea-level highstands of the last 150 ky, assigned to the Holocene and the Tyrrhenian (oxygen-isotope Substage 5e), respectively. The stratigraphic architecture of post-Substage 5e deposits shows consistent patterns of coastal evolution with changing sea-level position. Lowering of sea level between 125 and 70 ky (onset of Substages 5d and 5b, and Stage 4) resulted in extensive and repeated basinward shifts of facies, which can be observed across closely spaced unconformity surfaces associated to alluvial plain sedimentation (falling-stage systems tract). The general phase of sea-level fall was punctuated by short transgressive phases (Substages 5c, 5a and Stage 3 interstadials), which led to widespread deposition of organic-rich (lagoonal and swamp) deposits. Upper Stage 3 and Stage 2 deposits (lowstand systems tract) are replaced across a significant part of the study area by a hiatal surface. Holocene interglacial deposits are characterized by a retrogradational stacking pattern of coastal plain and littoral facies (transgressive systems tract), reflecting invariably the landward migration of a barrier–lagoon–estuary system. Subsequent highstand deposition (highstand systems tract) was characterized by extensive progradation of wave-influenced deltas and strandplains. The two major transgressive surfaces, of Tyrrhenian and Holocene age, are considerably easier to identify than the other key surfaces for sequence stratigraphic interpretation. The lowermost transgressive deposits display a pollen signature diagnostic of warm climate (interglacial) periods, showing wide forest development and relatively high pollen concentrations. By contrast, the deposits overlying the unconformable surfaces related to successive phases of sea-level fall are fingerprinted by pollen spectra dominated by Pinus and non-arboreal pollen types, with very low pollen concentrations, reflecting the onset of a stable cold climate vegetation characteristic of stadial to fully glacial conditions. The good match between facies architecture, pollen distribution and global sea-level evolution strongly suggests that Late Quaternary sedimentation in the Po Basin developed under a predominantly glacio-eustatic control. Stratigraphic architecture of the Po Basin thus can provide a useful analog for interpretation and correlation in the stratigraphic record of very rapid glacio-eustatic (fourth-order) cycles, with frequencies of about 100 ky.

In order to evaluate for the first time the application of boron isotope (δ11B) composition as a proxy for freshwater provenance in transitional environments, measurements taken from mollusk shells from palaeo-lagoonal deposits are presented herein. The mollusk specimens were sampled from late Quaternary lagoonal successions observed in the cores 187-S1 and Vignarca, respectively from drill-sites south of the Po River delta (Northern Italy) and the Cornia River plain (Central Italy). The latter locality occurs nearby the Larderello boron-rich geothermal area. A freshwater influence in the palaeo-lagoons has been highlighted by benthic foraminiferal analyzes, revealing two main assemblages: the first, dominated by Ammonia tepida (Cushman, 1926) and Ammonia parkinsoniana (d'Orbigny, 1839a), is consistent with high freshwater discharge into the palaeo-lagoon, whereas the second assemblage includes large numbers of Miliolacea, considered as reflecting low freshwater discharge. The inferred salinity variations are possibly constrained between 22‰ and 41‰, based on comparison with modern assemblages observed in various lagoons of the north Adriatic Sea and Tyrrhenian Sea coastal areas (e.g., Zampi & D'Onofrio, 1986; Coccioni, 2000). Additional Sr isotope data, comparable with coeval marine values, are consistent with the salinity range inferred by the fossil assemblages. Boron isotopes clearly record a continental-dominated provenance source of boron in the lagoonal mollusks collected from the Vignarca core. The low δ11B and boron-rich component currently observed in the continental water deriving from the geothermal area, was possibly also present in the freshwater feeding the palaeo-lagoon and gives a unique isotopic imprint to the analyzed samples. Conversely, in the lagoonal mollusks collected from core 187-S1, the δ11B component reveals a dominant provenance source of boron from seawater. In the analyzed successions, boron isotopes have proved useful for recognizing the provenance of the freshwater feeding the palaeo-lagoon, especially in areas characterized by continental water enriched in boron and showing remarkably different δ11B values with respect to marine values.

Integrating analysis of the benthic palaeoecological record with multivariate ordination techniques represents a powerful synergy able to provide an improved characterization of coastal depositional facies in a sequence stratigraphical perspective. Through quantitative analysis of benthic foraminifer, ostracod and mollusc associations from the postglacial succession of Core M3 (Arno coastal plain, Tuscany, Italy), and application of detrended correspondence analysis (DCA) to the mollusc sub-data set, we offer a refined picture of stratigraphical variations in faunal content from a paralic depositional setting, and reconstruct the palaeoenvironmental gradients that account for such variations. Despite distinct ecological behaviours, and taphonomic and sedimentological constraints, a strong ecological control on meio- and macrofaunal biofacies and taxa turnover is documented across the study succession. Amongst all possible mechanisms that may play a role in ‘shaping’ fossil distribution, the ecological signal driven by salinity represents the most prominent factor controlling the composition of fossil associations in the cored succession. Molluscs can even provide outstanding quantitative estimates of palaeosalinity along the sampled core. When plotted stratigraphically, the three fossil sub-data sets show consistent patterns of vertical evolution that enable prompt identification of the key surfaces for sequence stratigraphical interpretation in otherwise lithologically indistinguishable deposits. The concomitant maximum richness of species with strong marine affinity, paralleled by the highest DCA salinity estimates, allows recognition of the maximum flooding zone, dated to ∼7.7 cal. ka BP, within a homogeneous succession of outer lagoon clays. These clays are sandwiched between early transgressive, swamp to inner lagoon deposits and overlying prograding coastal−alluvial plain facies.

Classical (paleo-)ecological indices extracted from benthic foraminiferal assemblages are commonly applied to determine past environmental conditions.We tested the efficiency of selected indices (including wall type proportion, epifaunal/infaunal ratio and pooled diversity indices) on benthic foraminifera from a Holocene shallow marine succession of the Po Delta, in order to evaluate their advantages, limits and differences. The paleoenvironmental record was determined integrating species composition of assemblages. All indices clearly discriminated between low and high riverine influence, even though the boundary at three different core depths revealed their different sensitivity to the faunal response under hanging environmental conditions in terms of organic matter and sediment supply. Specifically, the lowest boundary was highlighted by wall structural types and epifaunal/infaunal ratio that were able to track the first inputs of organic matter provided by the prograding Po River mouths. Upward, low sand concentration and moderate foraminiferal abundance (expressed as Total Foraminiferal Number) indicated significant supplies of fine-grained sediments within a prodelta paleoenvironment. Lastly, diversity indices revealed stressful prodelta conditions with remarkable low diversity and high dominance values. We show that high paleoenvironmental resolution can be obtained through the integration of faunal indices, species composition and sediment grain size within deltaic successions, where many indices should be considered to comprehensively understand the onset of riverine influenced conditions.

Benthic foraminifera from stratigraphically expanded, late Quaternary prodelta successions of the Po Delta plain reveal small-scale paleoenvironmental variations within lithologically homogeneous deposits formed under conditions of rapid sedimentation (ca. 6 cm/yr). A detailed paleoenvironmental reconstruction was obtained comparing benthic foraminifera with shallow-water assemblages from the modern Po Delta. The integration with sediment geochemistry and radiocarbon dates was also tested to detect short time-scale delta dynamics controlled by autogenic factors. Core 7 records the development of an inner-shelf environment (interval A), replaced by a prodelta with strong fluvial influence, shown by the sharp increase in Ammonia tepida and Ammonia parkinsoniana (interval B). These taxa are replaced by Aubignyna perlucida (interval C) which indicates a major mouth shift (Ficarolo avulsion). Subsequent abrupt increases in A. tepida and A. parkinsoniana document a step-like progradation of the Po di Goro delta lobe (intervals D and E). In the seaward Core 1, possible minor mouth shifts are recorded by a sharp increase in A. tepida and A. parkinsoniana, paralleled by Cr/Al2O3 depletion. The upper portion of both prodelta successions includes stacked flood layers formed near the river mouth, as indicated by scarce A. tepida and A. parkinsoniana.