THE CAPO ROSSELLO BORE-HOLE (AGRIGENTO, SICILY) CYCLOSTRATIGRAPHIC AND PALEOCEANOGRAPHIC RECONSTRUCTIONS FROM QUANTITATIVE ANALYSES OF THE ZANCLEAN FORAMINIFERAL ASSEMBLAGES

Cyclostratigraphy based on the quantitative analyses of planktonic foraminifera in the Zanclean segment (M Pl 1 base of M Pl 3 biozones) of the bore-hole drilled in the Capo Rossello area (Sicily, Southern Italy) allows us to recognize that the calcareous plankton biostratigraphic events occur in the same cycles as identified by previous authors. Exceptional thick cycles which are thought to represent two precession cycles show two fluctuations is greater than the number of lithologic cycles. Between the base of the Pliocene and the first occurrence of Globorotalia puncticulata thirty-five lithologic cycles and thirty eight planktonic foraminifera fluctuations are present. By comparison with relative abundance fluctuations in the benthic foraminifera and the astronomical record is recognized. In particular, the BN>125 µm and the Planulina ariminensis quantitative distributions are related to the long eccentricity. Conversely, the relative abundance fluctuations of Siphonina reticulata, Cibicidoides bradyi, Pullenia bulloides and Uvigerina pygmaea appear to be generally forced by the precession periodicity, but in the intervals coincident with the eccentricity minima such a relationship is less clear. The very abundant and widespread distribution in several Mediterranean sites of S. reticulata, which we consider a quasi-endemic species of this basin during the Early and Middle Pliocene is anticovariant with the quantitative distribution of Cibicidoides brady-robertsonianus, which is considered a characteristic species of the North Atlantic Deep Water (NADW). This relationship suggest that a peculiar, intermediate water mass was present in the Mediterranean during this time interval. We propose for this water mass the name of Early Pliocene Mediterranenan Intermediate Water (EPMIW). According to bibliographic data that report the sharp decrease in abundance of S. reticulata during the M Pl 5 biozone, EPMIW was present in the Mediterranean basin until about 2.5 Ma.&nbsp

THE CAPO ROSSELLO BORE-HOLE (AGRIGENTO, SICILY) CYCLOSTRATIGRAPHIC AND PALEOCEANOGRAPHIC RECONSTRUCTIONS FROM QUANTITATIVE ANALYSES OF THE ZANCLEAN FORAMINIFERAL ASSEMBLAGES

Cyclostratigraphy based on the quantitative analyses of planktonic foraminifera in the Zanclean segment (M Pl 1 base of M Pl 3 biozones) of the bore-hole drilled in the Capo Rossello area (Sicily, Southern Italy) allows us to recognize that the calcareous plankton biostratigraphic events occur in the same cycles as identified by previous authors. Exceptional thick cycles which are thought to represent two precession cycles show two fluctuations is greater than the number of lithologic cycles. Between the base of the Pliocene and the first occurrence of Globorotalia puncticulata thirty-five lithologic cycles and thirty eight planktonic foraminifera fluctuations are present. By comparison with relative abundance fluctuations in the benthic foraminifera and the astronomical record is recognized. In particular, the BN>125 µm and the Planulina ariminensis quantitative distributions are related to the long eccentricity. Conversely, the relative abundance fluctuations of Siphonina reticulata, Cibicidoides bradyi, Pullenia bulloides and Uvigerina pygmaea appear to be generally forced by the precession periodicity, but in the intervals coincident with the eccentricity minima such a relationship is less clear. The very abundant and widespread distribution in several Mediterranean sites of S. reticulata, which we consider a quasi-endemic species of this basin during the Early and Middle Pliocene is anticovariant with the quantitative distribution of Cibicidoides brady-robertsonianus, which is considered a characteristic species of the North Atlantic Deep Water (NADW). This relationship suggest that a peculiar, intermediate water mass was present in the Mediterranean during this time interval. We propose for this water mass the name of Early Pliocene Mediterranenan Intermediate Water (EPMIW). According to bibliographic data that report the sharp decrease in abundance of S. reticulata during the M Pl 5 biozone, EPMIW was present in the Mediterranean basin until about 2.5 Ma.&nbsp

Hydroclimate variability in the central Mediterranean during MIS 17 interglacial (Middle Pleistocene) highlights timing offset with monsoon activity

Mediterranean climates are characterized by warm, dry summers and mild, rainy winters. Previous studies suggest that over the last 1.36 Myr, Mediterranean winter rainfalls were in phase with the African monsoon. Here we present a high-resolution terrestrial and marine dataset for the Marine Isotope Stage 17 interglacial (Middle Pleistocene) from Southern Italy, showing that precipitation rates and regimes in the central Mediterranean varied independently of the monsoon system. Specifically, events of extreme summer precipitation were promoted by increased regional insolation rates and/or extratropical cyclones, and their magnitude was further enhanced by the advection of cool and humid North Atlantic air during stadials. Our findings provide new information on the short- to mid-term natural hydroclimatic variability of the Mediterranean basin, and offer new critical insights on land–ocean interactions at the regional scale by complementing previous analyses on the displacement of storm tracks toward southern Europe

Mercury emissions from soils and fumaroles of Nea Kameni volcanic centre, Santorini (Greece)

There have been limited studies to date targeting mercury emissions from volcanic fumarolic systems, and no mercury flux data exist for soil or fumarolic emissions at Santorini volcanic complex, Greece. We present results from the first geochemical survey of Hg and major volatile (CO2, H2S, H2O and H2) concentrations and fluxes in the fumarolic gases released by the volcanic/hydrothermal system of Nea Kameni islet; the active volcanic center of Santorini. These data were obtained using a portable mercury spectrometer (Lumex 915+) for gaseous elemental mercury (GEM) determination, and a Multi-component Gas Analyzer System (Multi-GAS) for major volatiles. Gaseous Elemental Mercury (GEM) concentrations in the fumarole atmospheric plumes were systematically above background levels (~4 ng GEM m-3), ranging from ~4.5 to 121 ng GEM m-3. Variability in the measured mercury concentrations may result from changes in atmospheric conditions and/or unsteady gas release from the fumaroles. We estimate an average GEM/CO2 mass ratio in the fumarolic gases of Nea Kameni of approximately 10-9, which falls in the range of values obtained at other low-T (100°C) volcanic/hydrothermal systems (~10-8); our measured GEM/H2S mass ratio (10-5) also lies within the accepted representative range (10-4 to 10-6) of non-explosive volcanic degassing. Our estimated mercury flux from Nea Kameni's fumarolic field (2.56 × 10-7 t yr-1), while making up a marginal contribution to the global volcanic non-eruptive GEM emissions from closed-conduit degassing volcanoes, represents the first available assessment of mercury emissions at Santorini volcano, and will contribute to the evaluation of future episodes of unrest at this renowned volcanic complex

European and Mediterranean mercury modelling: local and long-range contributions to the deposition flux

Mercury (Hg) is a global pollutant that is known to have adverse effects on human health, and most human exposure to toxic methylmercury is through fish consumption. Soluble Hg compounds in the marine environment can be methylated in the water column and enter the base of the food chain. Atmospheric deposition is the most important pathway by which Hg enters marine ecosystems. The atmospheric chemistry of Hg has been simulated over Europe and the Mediterranean for the year 2009, using the WRF/Chem model and employing two different gas phase Hg oxidation mechanisms. The contributions to the marine deposition flux from dry deposition, synoptic scale wet deposition and convective wet deposition have been determined. The Hg deposition fluxes resulting from transcontinental transport and local/regional emission sources has been determined using both Br/BrO and O3/OH atmospheric oxidation mechanisms. The two mechanisms give significantly different annual deposition fluxes (129 Mg and 266 Mg respectively) over the modelling domain. Dry deposition is more significant using the O3/OH mechanism, while proportionally convective wet deposition is enhanced using the Br/BrO mechanism. The simulations using the Br/BrO oxidation compared best with observed Hg fluxes in precipitation. Local/regional Hg emissions have the most impact within the model domain during the summer. A comparison of simulations using the 2005 and 2010 AMAP/UNEP Hg emission inventories show that although there is a decrease of 33% in anthropogenic emissions between the two reference years, the total simulated deposition in the regions diminishes by only 12%. Simulations using the 2010 inventory reproduce observations somewhat better than those using the 2005 inventory for 2009