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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).

Transverse ridges are large topographic anomalies running adjacent to slow-slip oceanic transforms. They form due to different processes, including thermal stresses, hydration-dehydration of peridotites, non-linear viscoelastic rheology of the oceanic crust and vertical tectonic motions of lithospheric slivers induced by changes in ridge/transform geometry, causing transpression and/or transtension along the transform boundary. A prominent transverse ridge on the southern side of the Vema transform (Central Atlantic) rose probably between 12 and 10 Ma along the entire length (approximate to 320 km) of the transform, exposing a relatively undisturbed section of oceanic lithosphere. We used pelagic limestones encrusting serpentinized peridotites sampled from the lower slopes of the uplifted lithospheric section to date this uplift and define mechanisms of its emplacement. Ages were obtained both by micropaleontology (foraminifera and nannofossils) and by Sr-87/Sr-86 isotope ratios. No ages older than 12 Ma were obtained, even in samples recovered at sites with crustal ages (determined by magnetic anomalies) well over 12 Ma; on the other side, ages as young as 5.6-83 Ma were found in clusters of samples collected from the eastern part of the transverse ridge, probably due to mass-wasting episodes that rejuvenated the substratum. These results support the hypothesis that the Vema Transverse Ridge rose between 12 and 10 Ma due to flexural uplift related to transtension along the transform, in line with a general model whereby transverse ridges rise during discrete events as a consequence of changes in ridge-transform geometry. (C) 2017 Elsevier B.V. All rights reserved.

[1] Most oceanic islands are due to excess volcanism caused by thermal and/or compositional mantle melting anomalies. We call attention here to another class of oceanic islands, due not to volcanism but to vertical motions of blocks of oceanic lithosphere related to transform tectonics. Sunken tectonic islands capped by carbonate platforms have been previously identified along the Vema and Romanche transforms in the equatorial Atlantic. We reprocessed seismic reflection lines, did new facies analyses and 87Sr/86Sr dating of carbonate samples from the carbonate platforms. A 50 km long narrow paleoisland flanking the Vema transform, underwent subsidence, erosion, and truncation at sea level; it was then capped by a 500 m thick carbonate platform dated by 87Sr/86Sr at ∼11–10 Ma. Three former islands on the crest of the Romanche transverse ridge are now at ∼900 m bsl; they show horizontal truncated surfaces of oceanic crust capped by ∼300 m thick carbonate platforms, with 10–6 Ma Sr isotopic ages. These sunken islands formed due to vertical tectonics related to transtension/transpression along long-offset slow-slip transforms. Another tectonic sunken island is Atlantis Bank, an uplifted gabbroic block along the Atlantis II transform (SW Indian Ridge) ∼700 m bsl. A modern tectonic island is St. Peter and St. Paul Rocks, a rising slab of upper mantle located at the St. Paul transform (equatorial Atlantic). “Cold” tectonic islands contrast with “hot” volcanic islands related to mantle thermal and/or compositional anomalies along accretionary boundaries and within oceanic plates, or to supra-subduction mantle melting that gives rise to islands arcs.

A transform-parallel (transverse) ridge runs for several hundred kilometers along the northern side of the Romanche Fracture Zone (RFZ), being most prominent opposite to the eastern Mid Atlantic Ridge/transform intersection (RTI). Seismic reflection profiles and rock sampling indicate that the western part of the transverse ridge is made of uplifted slivers of oceanic lithosphere. In contrast, the eastern part (east of the RTI) consists of a thick (>4 km) sedimentary succession affected by faulting and thrusting. We call it the Romanche Sedimentary Sequence (RSS). If this sedimentary sequence were underlain by oceanic crust, its predicted age should be not more than ∼60 Ma. However, dolomitized Maiolica-type pelagic limestones containing calpionellids of early Cretaceous age (∼140 Ma) were sampled from the RSS, in addition to Paleocene/Eocene quartzs and stones, siltstones, claystones, diatomites, and limestones. We present a description of the rock samples and a reconstruction of their environment of deposition and of their age. The RSS may represent material deposited during initial continent/continent transform motion in a narrow, deep, E–W elongated basin that communicated with the central Atlantic. The RSS was later subjected to transpression and uplift due to transform-related tectonics. Gabbros, but not basalts, were sampled from the igneous basement underlying the RSS. It is not clear whether the RSS overlies oceanic crust or some sort of pre-oceanic, northern Red Sea-type crust. The presence of lower Cretaceous pelagic deposits near the Romanche eastern RTI implies an age for the initial stage of the opening of the equatorial Atlantic older than the generally assumed Aptian/Albian.

The planktic foraminiferal distribution identified in 60 cores collected in different basins of the Mediterranean Sea allowed to establish an ecostratigraphical scheme which provides a very important tool for the biochronological subdivision of the uppermost Quaternary. We identified a succession of ten ecozones during the last 23 ka in the Tyrrhenian basin and eight ecozones in the Adriatic Sea during the last 15 ka. The ecozones boundaries have been calibrated by 14C AMS radiometric data and by the stable oxygen isotope record. The chronological framework defined by the successive bioevents shows a very high resolution (millenary scale) and evidences that the changes in the planktic microfauna occurred more or less synchronously throughout the central Mediterranean Sea. Differences due to different oceanographic settings of the basins do not affect the general distributional pattern of planktic foraminifera.

The Romanche transverse ridge (equatorial Atlantic) is located in the northern flank of the fracture zone, opposite the eastern ridge-transform intersection (RTI). It constitutes a major positive topographic anomaly that reaches a height of over 4 km above the level predicted by the thermal subsidence curve. A series of E–W aligned peaks, located on the crest of the transverse ridge, were at sea level during early and middle Miocene times; they are presently capped by a ~300 m thick, shallow-water carbonate platform that grew on a subsiding oceanic crust basement surface flattened by erosion at sea level. These structures are now about 1 km below sea level. High resolution seismic reflection surveys and multibeam morphobathymetry as well as study of samples recovered from the carbonate platform allowed a reconstruction of the paleoenvironment and of the vertical movements of the peaks starting from the lower Miocene. Ages derived from microfossils suggest that the base of the carbonate platform dates from 17–25 m.y. ago and the sinking of the platform started between 18 and 13 m.y. ago. These data were included in a numerical simulation model that takes into account thermal and tectonic subsidence, growth potential of the carbonates, subaerial and submarine erosion rates and Mio-Pliocene absolute sea level fluctuations. The results outline the subsidence history of the Romanche transverse ridge and suggest post-Miocene subsidence faster than that predicted by the thermal cooling model.

Jorissen, F.J., Asioli, A., Borsetti, A.M., Capotondi, L., De Visser, J.P., Hilgen, F.J., Rohling, E.J., Van der Borg, K., Vergnaud Grazzini, C. and Zachariasse, W.J., 1993. Late Quaternary central Mediterranean biochronology. Mar. MicropaleontoL, 21: 169-189. A high-resolution biochronology is presented for the Late Quaternary of the central Mediterranean. In the Late Pleistocene-Holocene successions three assemblage zones are distinguished on the basis of frequency patterns of planktic foraminifera. The age of these zones is determined by Accelerator Mass Spectrometry (AMS) t4C dating. The zonal boundaries are dated at 12,700 yr B.P. (the end of Termination la) and 9600 yr B.P. (the start of Termination Ib), respectively. The AMS dates show that major changes in the planktic and benthic realms occurred synchronously over wide areas, although records of individual species may show important regional differences. In the studied areas, resedimentation processes revealed by anomalous successions of 14C dates, play a far more important role than indicated by the sedimentological and micropaleontological data. Possibly these processes contribute to the very high accumulation rates in the glacial Zone IlL Although the AMS technique has increased the accuracy of laC-measurements, of older carbonate may still lead to substantial age differences between areas with different sedimentary regimes.

Benthic foraminiferal thanatocoenoses were studied in 29 sediment surface samples off NW Africa, between 19° and 27°N, and from water depths between 506 and 3314 m. The results were compared with estimated values of the downward organic flux and measured bottom water oxygen concentrations. Although the latter 2 parameters show a strong negative correlation in the study area, we argue that the organic flux is the main controlling ecological factor. On the basis of an R-mode multivariate statistical analysis, 6 species clusters are recognized, which are separated geographically by differences in organic flux and water depth. The combined sample scores on the first 2 principal component axes show a strong positive correlation with the estimated downward organic flux (R 2 = 0.83). It is suggested that this relationship can be used on a local scale as a proxy for paleo-export production, as long as bottom water oxygenation does not fall below a critical level.

The finding in two cores, collected in the Southern Adriatic, of sediments rich in diatoms and radiolaria and almost completely lacking in benthic forams, testifies to an environmental situation comparable with that in the Northern Adriatic. This situation must have persisted for long enough to be registered in the sediment. It is interpreted as the Adriatic's response to the extreme oceanographic conditions causing deposition of the Sapropel S1 in the Eastern Mediterranean.

The palaeoceanographic evolution of the Levantine waters during the last deglacial time is investigated using the sedimentary record of a deep sea core, CS 70-5, from the Linosa basin (35° 44.4′N/13° 11.0′E, 1486 m water depth). Radiocarbon dating and oxygen isotope stratigraphy based on 18 O changes in Globigerina bulloides allow us to recognize and to date the different steps of the deglaciation. These steps are synchronous with those reported in the North Atlantic, but correspond to a δ 18 O decrease of higher amplitude than in the Alboran sea or in the North Atlantic Ocean. Major faunal events permit the establishment of a local biozonation which differs from those reported either for the Alboran sea or the Eastern Mediterranean basin. Major breaks in the faunal assemblages occurred during Termination I A , within the first step of the deglaciation around 14 kyr B.P., and near 10.6 kyr B.P. within the Younger Dryas. The onset of the last deglaciation induced important changes in the characteristics of the Levantine and Atlantic water masses which occupied the Strait of Sicily. The δ 13 C records of Globigerina bulloides and Cibicidoides pachyderma indicate that the modifications observed in the assemblages of deep faunas are controlled by the oxygenation of the water column. δ 13 C records of Globigerina bulloides are similar throughout the West Mediterranean as well as in sediments located below the present Mediterranean outflow. The distributional pattern as well as its δ 13 C record suggest that this species could be a good recorder of the upper Levantine waters and, more precisely, of the mixing layer of the overlying Atlantic waters with the Levantine ones. Major influxes of Atlantic waters during Terminations I A and I B could have slowed down the vertical mixing of the different water layers present in the Strait of Sicily and caused a decrease in the oxygenation of the water column. During Termination I B the effect of Atlantic influxes was reinforced by the occurrence of a low salinity layer in the eastern basin which led to the stagnation of the deep waters. The two episodes of decreased oxygenation in the Levantine waters also favored the precipitation of inorganic magnesium calcite.

ACCORDING to palaeogeographic reconstructions, the equatorial Atlantic Ocean basin started to open in the Cretaceous period, not earlier than 120 Myr ago1–3. From this and a conventional description of the process of sea-floor spreading, one would expect the oldest oceanic crust in this region to be 120 Myr old, and to be found at the edges of the ocean basin. Contrary to these expectations, we report here the recovery of 140-Myr-old 'Maiolica'-type pelagic limestones from the centre of the basin, near the intersection of the Mid-Atlantic Ridge and the Romanche transform fault. The limestones occur within a tecto-nically deformed and uplifted sedimentary sequence, > 4km thick and > 200 km long, which includes continent-derived quart-zitic siltstones of Palaeocene and Eocene age. This sequence probably accumulated in a proto-Romanche transform valley that was connected to a palaeo-central-Atlantic basin, indicating that continental separation had already started here 140 Myr ago. The entrapment of these old deposits within younger ocean crust can be explained by repeated ridge jumping and transform migration during the evolution of the equatorial Atlantic.