VOLCANIC CONTRIBUTIONS TO SEDIMENTATION IN UPPER BURDIGALIAN-LOWER LANGHIAN SEDIMENTS OF THE VENETIAN MOLASSIC BASIN

In the Upper Burdigalian-Lower Langhian sediments of the Venetian molassic basin two vol­caniclastic layers are clearly recognizable, respectively within the Globigerinoides trilobus and Praeorbulina glomerosa zones of Bizon & Bizon (1972). The chemical composition of well-preserved glass shards, tested by electron microprobe, reveals rhy­olitic composition and provides information about contemporaneous acidic explosive volcanism. Due to the probably depositional mechanism (fallout), the location of the effusive centres remains unknown. Although many ash layers are quite well-known in the same stratigraphic interval throughout the Apennine chain, a ten­tative correlation still seems very difficult, due to different methods of analysis and dating criteria

The epidemiology of mumps in Italy

In Italy, although vaccination has been recommended for a number of years, vaccination coverage for mumps is still sub-optimal. The objective of the present study was to evaluate the seroprevalence of mumps antibodies in the Italian population, stratified by age, gender and geographical area. The proportion of individuals positive for mumps antibodies remained stable in the age classes 0-11 months and 1 year (25.4% and 30.8%, respectively) and showed a continuous increase after the second year of life. The percentage of susceptible individuals was higher than 20% in persons 2-14 years of age and exceeded 10% in persons 15-39 years of age. No statistically significant differences were observed by gender or geographical area. Comparison between these results and the data obtained from a 1996 survey showed a statistically significant increase in seroprevalence in the age class 2-4 years. No changes were observed in the other age-groups. The results of this study confirm that the efforts made in recent years to improve vaccination coverage within the second year of life should be strengthened. \ua9 2008 Elsevier Ltd. All rights reserved

Proposal for the Global Boundary Stratotype Section and Point (GSSP) for the Priabonian Stage (Eocene) at the Alano section (Italy)

The base of the Priabonian Stage is one of two stage boundaries in the Paleogene that remains to be formalized. The Alano section (NE Italy) was elected by consensus as a suitable candidate for the base of the Priabonian during the Priabonian Working Group meeting held in Alano di Piave in June 2012. Further detailed research on the section is now followed by a formal proposal, which identifies the base of a prominent crystal tuff layer, the Tiziano bed, at meter 63.57 of the Alano section, as a suitable candidate for the Priabonian Stage. The choice of the Tiziano bed is appropriate from the historical point of view and several bio-magnetostratigraphic events are available to approximate this chronostratigraphic boundary and guarantee a high degree of correlatability over wide geographic areas. Events which approximate the base of the Priabonian Stage in the Alano section are the successive extinction of large acarininids and Morozovelloides (planktonic foraminifera), the Base of common and continuous Cribrocentrum erbae and the Top of Chiasmolithus grandis (nannofossils), as well as the Base of Subchron C17n.2n and the Base of Chron C17n (magnetostratigraphy). Cyclostratigraphic analysis of the Bartonian-Priabonian transition of the Alano section as well as radioisotopic data of the Tiziano tuff layer provide an absolute age (37.710 – 37.762 Ma, respectively) of this bed and, consequently, of the base of the Priabonian Stage

Fracture networks on the Belluno syncline, a fault-propagation fold in the footwall of the Belluno thrust, Venetian Alps, NE Italy

The Belluno syncline is a structure located in the Venetian fold-and-thrust belt in the Italian Southern Alps. This SSE-vergent chain mainly developed during the Neogene as a back-thrust belt of the Alps deforming the northern margin of the Adria plate. The syncline is asymmetric in shape, with a steep backlimb, as the forelimb of the paired Monte Coppolo Anticline; it is the result of fault-propagation folding during the development of the underlying Belluno thrust. In plan view the Belluno thrust shows a prominent curvature interpreted as reactivation of inherited Mesozoic extensional structures. The hinge of the Belluno syncline presents a similar curvature. Rocks cropping out in the syncline core are Upper Chattian to Langhian fine-grained molassic sediments, mainly siltstones and marls. Most fractures on the Belluno syncline have formed at high angles to bedding. The dominant fracture trends are subparaUel and orthogonal to the fold hinge. Sometimes these fractures show plumose structures revealing extension (Mode I) fracture mechanism and therefore they are referred to as longitudinal (bc) joints and cross (ac) joints respectively. Other fracture trends oblique to the hinge line are found in measurement stations located on limbs distant from the fold hinge. They are referred to as oblique (shear) fractures. Throughout the western part of the Belluno syncline the fracture network maintains a roughly symmetrical distribution with respect to the fold hinge, suggesting a development in association with folding

La sedimentazione aquitaniano-langhiana nei settori friulano e veneto

80a Riunione Estiva Soc. Geol. It., Riassunti delle comunicazioni e dei poste

Alternation of ecologic regimes in a deep-marine carbonate basin: calciturbidites trace fossils from the Cretaceous Scaglia Rossa, northeastern Italy

The mostly pelagic Scaglia Rossa limestone exposed in the Vich quarry near Belluno contains numerous light-colored turbidites, consisting of calcareous sandstone and mudstone derived from the adjacent Friuli Platform. The turbidites contain an ichnofauna that records short-lived departures from background conditions in this part of the Belluno Basin in the Late Cretaceous. At least seven distinctive ichnotaxa were recognized, some of which could be the parts or extensions of more complex burrow systems of deposit feeders that exploited the disturbances. Earliest exploitation of the individual turbidites is indicated by nondescript burrow mottling in the lowest sandstone divisions. This is followed by an ensemble of comparatively well preserved sand-filled and typically mud-lined/-mantled burrows produced as the mud fraction began to accumulate gradually from suspension. All of these structures are crosscut by a latest series of mud-filled tunnels. This is not exactly the pattern of siliciclastic turbidites of flysch successions, having post-event ichnoassociations consisting of traces that are more nearly contemporaneous and record either depth of penetration or post-depositional movement of the redox boundary. Because the mud component in the Vich turbidites may have required several months to settle out of suspension, the patterns of bioturbation were extended over months to years. But as in the case of siliciclastic turbidites, emplacement of the calciturbidites. suppressed the background fauna and supported a post-event association of different endobenthic animals, by changing temporarily the physical properties of the substrate, providing a windfall of organic particles, and by ventilating the near-bottom water