11 research outputs found
Early-Middle Pleistocene benthic turnover and oxygen isotope stratigraphy from the Central Mediterranean (Valle di Manche, Crotone Basin, Italy): data and trends
Ostracod faunal turnover and oxygen isotope data (foraminifera) along the Valle di Manche (VdM) section are herein compiled. Specifically, the material reported in this work includes quantitative palaeoecological data and patterns of ostracod fauna framed within a high-resolution oxygen isotope stratigraphy (δ18O) from Uvigerina peregrina. In addition, the multivariate ostracod faunal stratigraphic trend (nMDS axis-1 sample score) is calibrated using bathymetric distributions of extant molluscs sampled from the same stratigraphic intervals along the VdM section. Data and analyses support the research article “Dynamics of benthic marine communities across the Early-Middle Pleistocene boundary in the Mediterranean region (Valle di Manche, Southern Italy): biotic and stratigraphic implications” Rossi et al. [1]
Magnetic fabric of Plio-Pleistocene sediments from the Crotone fore-arc basin: Insights on the recent tectonic evolution of the Calabrian Arc (Italy)
Low-field anisotropy of magnetic susceptibility (AMS) analyses were performed on 532 samples col-lected in 36 (mostly lower Pliocene to lower Pleistocene) marine clay sites from the Crotone basin, afore-arc basin located on top of the external Calabrian accretionary wedge. The Crotone basin formedsince mid-late Miocene under a predominant extensional tectonic regime, but it was influenced there-after by complex interactions with NW–SE left-lateral strike-faults bounding the basin, which also yieldedpost-1.2 Ma ~30◦counterclockwise block rotations. The basin is filled by continental to marine sedimentsyielding one of the thickest and best-exposed Neogene succession available worldwide. The deep-marinefacies – represented by blue-grey marly clays gave the best results, as they both preserved a clear mag-netic fabric, and provided accurate chronology based on previously published magnetostratigraphy andcalcareous plankton (i.e. foraminifers and nannofossils) biostratigraphy. Magnetic susceptibility rangeand rock magnetic analyses both indicate that AMS reflects paramagnetic clay matrix crystal arrange-ment. The fabric is predominantly oblate to triaxial, the anisotropy degree low (<1.06), and the magneticfoliation mostly subparallel to bedding. Magnetic lineation is defined in 30 out of 36 sites (where thee12 angle is <35◦). By also considering local structural analysis data, we find that magnetic fabric wasgenerally acquired during the first tectonic phases occurring after sediment deposition, thus validatingits use as temporally dependent strain proxy. Although most of the magnetic lineations trend NW–SE andare orthogonal to normal faults (as observed elsewhere in Calabria), few NE–SW compressive lineationsshow that the Neogene extensional regime of the Crotone basin was punctuated by compressive episodes.Finally, compressive lineations (prolate magnetic fabric) documented along the strike-slip fault boundingthe basin to the south support the significance of Pleistocene strike-slip tectonics. Thus the Crotone basinshows a markedly different tectonics with respect to other internal and western basins of Calabria, asit yields a magnetic fabric still dominated by extensional tectonics but also revealing arc-normal short-ening episodes and recent strike-slip fault activity. The tectonics documented in the Crotone basin iscompatible with a continuous upper crustal structural reorganization occurring during the SE-migrationof the Calabria terrane above the Ionian subduction system.Published67-791A. Geomagnetismo e PaleomagnetismoJCR Journalrestricte
A high-resolution record of the Matuyama-Brunhes transition from the Mediterranean region: The Valle di Manche section (Calabria, Southern Italy)
High-resolution palaeomagnetic and rock magnetic investigations on the Valle di Manche section (Crotone Basin, Calabria, Southern Italy) provide a detailed record of the Matuyama-Brunhes (M-B) reversal that, to our best knowledge, is the only available record of the last geomagnetic reversal for the Mediterranean on-land marine stratigraphy. The M-B transition can be pinpointed precisely, as it develops within a 3-cm-thick interval located just above a prominent tephra layer (the “Pitagora ash”) where the sedimentation rates are about 27 cm/kyr. Demagnetization analyses indicate a stable palaeomagnetic behaviour throughout the section for both normal and reversed polarity directions, with demagnetization vectors aligned toward the origin of Zijderveld diagrams after the removal of a small viscous low-coercivity remanence component. In the lower part of the studied interval, some samples acquired a spurious gyromagnetic remanent magnetization (GRM) during AF demagnetization in high fields. Rock magnetic analyses confirm that magnetite is the main magnetic carrier for all measured specimens, which also have an abundant paramagnetic fraction. Only the lower part of the record, well below the M-B boundary, is characterized by a downward-increasing presence of iron sulphides (greigite). According to our chronology, which is based on a robust, cross-validated age model, the final reverse-to-normal directional change of the M-B transition occurred at ca. 786.9 ± 5 ka (error includes uncertainty in orbital tuning) and was very rapid, of the order of 100 years or less
The Lower to Middle Pleistocene Valle di Manche section (Calabria, Southern Italy): state of the art and current advances
The Valle di Manche (VdM) section represents one of the best-documented on-land marine records of
the Early to Middle (E/M) Pleistocene transition available to date. Accordingly, the VdM succession is
among the few appropriate candidates to host the GSSP of the Middle Pleistocene (“Ionian”) Stage. In
particular, the VdM section uniquely documents the MatuyamaeBrunhes magnetic reversal (mid-MIS
19), which is agreed to be the main criterion for defining the chronostratigraphic position of the base of
the Middle Pleistocene. The section also yields a wide range of chronological, paleoclimatic and stratigraphic
data sets that allow long-distance correlation with both marine and terrestrial reference records.
Notably, the stratigraphy across the MIS 19 interglacial is greatly expanded, permitting a precise and
detailed investigation of this critical interval. The section is also easy to reach, and fortunately the
exposure is destined to persist. Therefore, the section fulfills the essential requirements to host the GSSP
for the “Ionian” Stage and Middle Pleistocene Subseries. We suggest that the GSSP be placed at the base
of the “Pitagora ash”, a prominent bed that occurs in mid-MIS 19, close to the MatuyamaeBrunhes
magnetic reversal. Here, we present and discuss scientific information gathered in the past two decades,
and give a preliminary account of the work to which we are presently committed, that aims at improving
our knowledge on the VdM section
Marine ostracod turnover tracks orbitally forced palaeoenvironmental changes at the Lower-Middle Pleistocene transition: the case study of the Valle di Manche section (Calabria, southern Italy)
Ostracods, small crustaceans living in almost every aquatic depositional setting, are widely used in palaeoenvironmental reconstructions due to their well-known ecological sensitivity. A close connection between the composition of ostracod fauna and the Milankovitch climate-eustatic variability has been documented in several Plio-Pleistocene marine sections of the Central Mediterranean area. The Valle di Manche section (VdM; Calabria, southern Italy), one of the suitable candidates to host the Global Stratotype Section and Point (GSSP) of the Ionian Stage-Middle Pleistocene, represents an ideal venue where to investigateostracodturnoverinrelationtoorbitallyforcedpalaeoenvironmentalchanges,being\ufb01rmlyconstrained in time and well documented by a number of independent climatic proxy. A high-resolution, quantitative analysis of the ostracod fauna has been undertaken on the middle part of the VdM, ca. 30 m-thick and showing two T-R cycles developed at the Lower-Middle Pleistocene transition (late MIS 21 to early MIS 18). Within each cycle, a relatively thin, \ufb01ning-upward transgressive muddy unit is overlain by gradually coarsening upward and more expanded regressive silty to sand packages. A total of 40 samples have been selected to characterise the whole spectrum of lithofacies and detect highfrequency palaeoenvironmental variations especially within homogeneous clayey stratigraphic intervals. Taxa typical of circalittoral (>70/100 m) depths (e.g., Bosquetina dentata, Cytherella vulgatella, Cytheropteron monoceros, Pterygocythereis ceratoptera and Krithe species), commonly accompanied by the lower circalittoralbathyal species Henryhowella sarsii, occur within the \ufb01ne-grained units developed during the full interglacials of MIS 21 and MIS 19. Furthermore, ostracod assemblages document that the oxygen availability at the sea \ufb02oor changed during MIS 19. In contrast, a less-diversi\ufb01ed ostracod fauna dominated by Aurila convexa, a species preferring vegetated sandy substrates in the upper circalittoral zone, characterises coarser glacial deposits. Atop the sandy successions A. convexa is partially replaced by Semicytherura ruggierii, suggesting a further decrease in palaeobathymetry and, possibly, an increase in riverine in\ufb02uence. Within each T-R cycle vertical changes in ostracod fauna track both an overall deepening-shallowing upward trendandhigh-frequencyvariationsinstratalstackingpatterns,allowingthepreciseidenti\ufb01cationofkeysequence stratigraphic surfaces: Transgressive Surface (TS) and Maximum Flooding Surface (MFS). The former, which is marked by a sharp increase in Krithe, Cytherella and Cytheropteron species, develops during the late d18O glacial termination. The MFS, invariably highlighted by concomitant highest and lowest percentages of H. sarsii and A. convexa respectively, matches the lightest d18O values recorded by foraminifers and corresponding to full interglacial conditions. Within the MIS 19 muddy unit, the MFS is identi\ufb01ed few decimeters above the Pitagora ash layer, a prominent bed close to the Matuyama-Brunhes geomagnetic reversal
The lower to Middle Pleistocene Valle di Manche section (Calabria, Southern Italy): State of the art and current advances
The Valle di Manche (VdM) section represents one of the best-documented on-land marine records of
the Early to Middle (E/M) Pleistocene transition available to date. Accordingly, the VdM succession is
among the few appropriate candidates to host the GSSP of the Middle Pleistocene (\u201cIonian\u201d) Stage. In
particular, the VdM section uniquely documents the MatuyamaeBrunhes magnetic reversal (mid-MIS
19), which is agreed to be the main criterion for defining the chronostratigraphic position of the base of
the Middle Pleistocene. The section also yields a wide range of chronological, paleoclimatic and stratigraphic
data sets that allow long-distance correlation with both marine and terrestrial reference records.
Notably, the stratigraphy across the MIS 19 interglacial is greatly expanded, permitting a precise and
detailed investigation of this critical interval. The section is also easy to reach, and fortunately the
exposure is destined to persist. Therefore, the section fulfills the essential requirements to host the GSSP
for the \u201cIonian\u201d Stage and Middle Pleistocene Subseries. We suggest that the GSSP be placed at the base
of the \u201cPitagora ash\u201d, a prominent bed that occurs in mid-MIS 19, close to the MatuyamaeBrunhes
magnetic reversal. Here, we present and discuss scientific information gathered in the past two decades,
and give a preliminary account of the work to which we are presently committed, that aims at improving
our knowledge on the VdM section
Paleomagnetic and rock magnetic study of sedimentary cores from the continental slopeof the Ross Sea (Antarctica).
Sediment property changes in response to the glacial activity on the continental slope to the eastern side of Pennell-Iselin Bank in the Ross Sea, Antarctica.
Metabolic alteration transients during paroxysmal activity in an epileptic patient with fixation-off sensitivity: a case study
The purpose of this study was to investigate short-time metabolic variations related to continuous epileptic activity elicited by fixation-off sensitivity (FOS). Time-resolved magnetic resonance spectroscopy was performed on a patient on whom previous clinical findings clearly indicated presence of FOS. The epileptic focus was localized with a simultaneous electroencephalographic and functional magnetic resonance imaging study. The results showed a linear increase of the sum of glutamate and glutamine with time of paroxysmal activity in epileptic focus and much greater concentration of choline-containing compounds in focus than in the contralateral side. \ua9 2006 Elsevier Inc. All rights reserved
Coexpression of \u394Np63/p40 and TTF1 Within Most of the Same Individual Cells Identifies Life-Threatening NSCLC Featuring Squamous and Glandular Biphenotypic Differentiation: Clinicopathologic Correlations
Introduction: Double occurrence of TTF1 and \u394Np63/p40 (henceforth, p40) within the same individual cells is exceedingly rare in lung cancer. Little is known on their biological and clinical implications. Methods: Two index cases immunoreactive for both p40 and TTF1 and nine tumors selected from The Cancer Genome Atlas (TCGA) according to the mRNA levels of the two relevant genes entered the study. Results: The two index cases were peripherally located, poorly differentiated, and behaviorally unfavorable carcinomas, which shared widespread p40 and TTF1 decoration within the same individual tumor cells. They also retained SMARCA2 and SMARCA4 expression, while variably stained for p53, cytokeratin 5, and programmed death-ligand 1. A subset of basal cells p40+/TTF1+ could be found in normal distal airways. Biphenotypic glandular and squamous differentiation was unveiled by electron microscopy, along with EGFR, RAD51B, CCND3, or NF1 mutations and IGF1R, MYC, CCND1, or CDK2 copy number variations on next-generation sequencing analysis. The nine tumors from TCGA (0.88% of 1018 tumors) shared the same poor prognosis, clinical presentation, and challenging histology and had activated pathways of enhanced angiogenesis and epithelial-mesenchymal transition. Mutation and copy number variation profiles did not differ from the other TCGA tumors. Conclusions: Double p40+/TTF1+ lung carcinomas are aggressive and likely underrecognized non-small cell carcinomas, whose origin could reside in double-positive distal airway stem-like basal cells through either de novo-basal-like or differentiating cell mechanisms according to a model of epithelial renewal