Recent dolomite in playa lakes of the central Ebro Basin, Spain

Elemental geochemistry of soils from the volcanic island of Pantelleria, Sicily: implications for Moscato wine production.

The volcanic island of Pantelleria produces a naturally sweet wine Moscato di Pantelleria DOC obtained from the «Moscato d'Alessandria» (or «Zibibbo»), a grape favoured by hot climate. Geochemical and mineralogical investigations performed on soil profiles devoloped on rocks representative of the major outcropping lithologies (pantellerite, trachyte and alkalic basalt) show that the soils have preserved the parent material imprint. Consistently, values of the chemical index of alteration (CIA) indicate a low to moderate weathering degree for the rocks exposed in the Pantelleria area and consequently a low to moderate soil evolution. Soil-solution chemical analyses highlight that macro- and …

Orbitally induced limestone/marlstone rhythms in the Albian—Cenomanian Cismon section (Venetian region, northern Italy): Sedimentology, calcareous and siliceous plankton distribution, elemental and isotope geochemistry

Abstract A multidisciplinary study of the upper Albian—Cenomanian portion of the Cismon section (Venetian region, northern Italy) was undertaken in order to characterize the cyclic alternations of carbonate-rich and carbonate-poor layers and to investigate their possible origin and cyclic patterns. Limestone semicouplets are characterized by abundant radiolarians and micarbs (micron-sized calcitic fragments), common planktonic foraminifera, strong bioturbation, good oxygenation as expressed by the Mn* and V/(V+Ni) parameters, high Si/Al ratio, low K/Al, in the absence of pyrite and organic matter. The marlstone semicouplets are, on the contrary, frequently laminated, rich in pyrite and orga…

Heavy metal contamination and bioproductivity record in box-core sediments from the Strait of Sicily, central Mediterranean.

Biogeochemical evaluation of historical sediment contamination in the Gulf of Palermo (NW Sicily): Analysis of pseudotrace elements and stable isotope signals

Abstract Sedimentary biogeochemical data from the Gulf of Palermo, which borders one of the major urban and industrial areas of the central Mediterranean, provide a decennial–centennial-scale record of the effects of human activity on this coastal environment. In this study we report trace elements (TE), C org /N tot ratios, δ 13 C org , and δ 15 N tot from dated ( 210 Pb) sediments collected in two coastal stations variably influenced by urban/fluvial loadings and illegal dumping and we compare them with published data for offshore sediments, in order to investigate at a large spatial scale the influence of on-land activities on sedimentary marine system. TE were generally low except for H…

Distribution of REEs in box-core sediments offshore an industrial area in SE Sicily, Ionian Sea: Evidence of anomalous sedimentary inputs

The distribution of rare earth elements and yttrium (REEs+Y) has been investigated in box-core sediments recovered from four stations in the Sicilian coastal zone seawards of Augusta, one of the most industrialized and contaminated areas in the Mediterranean region. Shale-like REE patterns and low Y/Ho ratios (close to the chondritic ratio) suggest a dominant terrigenous (geogenic) source for REE. Slight enrichment of LREE over the HREE is interpreted as due to preferential adsorptive transfer of LREE from seawater to sediment particles. Samples from offshore cores exhibit slightly positive Gd and negative Ce anomalies. It is here hypothesized that main drivers of anthropogenic Gd flux towa…

Sedimentary record of anthropogenic contaminants (trace metals and PAHs) and organic matter in a Mediterranean coastal area (Gulf of Palermo, Italy)

Abstract The Gulf of Palermo (Italy, Mediterranean Sea) is a contaminated coastal environment with a relatively high influx of unregulated industrial and domestic effluents. Two sediment box-cores were collected at water depths of 100 and 712 m. Samples were analysed for trace metals (As, Cu, Hg, Mn, Ni, Pb), total polycyclic aromatic hydrocarbons (ΣPAHs), organic carbon to total nitrogen (Corg/Ntot) ratios and organic carbon and nitrogen isotopic composition (δ13Corg and δ15Ntot). At the coastal site, trace metal and ΣPAH depth profiles show a clear upcore increase, indicating increasing contamination over the recent past. Concentrations of ΣPAHs, Hg, Pb, Cu, and As appear to be potentiall…

Geochemistry and mineralogy of sediments and authigenic carbonates from the Malta Plateau, Strait of Sicily (Central Mediterranean): Relationships with mud/fluid release from a mud volcano system

Abstract A mud volcano field was recently discovered within the Malta Plateau in the Strait of Sicily (Central Mediterranean Sea). Box-core sediments and associated authigenic carbonates have been collected in water depths of 140–170 m from two distinctive sectors of the area, and analyzed for major, trace and rare earth elements, stable isotopes, and mineralogy. Relative homogeneity in the mineralogy and geochemistry of bulk sediments, and 210Pb activity distributions, argue against an active mud ejection activity. In the Malta Plateau western sector, the sediments show high concentrations of Fe, As, Sb, and Mo, exceeding the background values estimated for the Strait of Sicily. Active flu…

Carbonate stromatolites from a Messinian hypersaline setting in the Caltanissetta Basin, Sicily: petrographic evidence of microbial activity and related stable isotope and rare earth element signatures

Lower Messinian stromatolites of the Calcare di Base Formation at Sutera in Sicily record periods of low sea-level, strong evaporation and elevated salinity, thought to be associated with the onset of the Messinian Salinity Crisis. Overlying aragonitic limestones were precipitated in normal to slightly evaporative conditions, occasionally influenced by an influx of meteoric water. Evidence of bacterial involvement in carbonate formation is recorded in three dolomite-rich stromatolite beds in the lower portion of the section that contain low domes with irregular crinkly millimetre-scale lamination and small fenestrae. The dominant microfabrics are: (i) peloidal and clotted dolomicrite with c…

Dall’Oceano anossico del Cretaceo alle attuali spiagge della Riserva dello Zingaro, Sicilia

Impact of human activities on the central Mediterranean offshore: Evidence from Hg distribution in box-core sediments from the Ionian Sea

The Palermo and Augusta urban/industrial areas (Sicily) are examples of contaminated coastal environments with a relatively high influx of unregulated industrial and domestic effluents. Three sediment box-cores were collected offshore of these urban/industrial areas in water depths of 60–150mduring two cruises (summers 2003/2004), dated by 210Pb and 137Cs, and analysed for total mercury concentration and total polycyclic aromatic hydrocarbon (PAH) concentration. Benthic foraminiferal assemblages were also examined (in terms of their distribution and morphology) to assess the potential use of benthic foraminifera as bioindicators of pollutant input and environmental change in these Mediterra…

Biomineralization events in Recent volcanic and sedimentary settings: textural features and isotope signatures.

Cenomanian-Turonian carbon-isotope stratigraphy for Italy and northern Africa: peculiar features of a Bonarelli Level (Novara di Sicilia section) in northeast Sicily

A geochemical comparison between OAE2 (Cretaceous) and Sapropel S1 (Holocene)

Analysis and assessment of trace element contamination in offshore sediments of the Augusta Bay (SE Sicily): A multivariate statistical approach based on canonical correlation analysis and mixture density estimation approach

Abstract An application of multivariate statistical methods is provided to identify anthropogenic contaminants and lithogenic elements in offshore sediments collected near the heavily industrialized Augusta Bay, Sicily. An exploratory statistical technique, based on canonical correlation analysis (CCA) and mixture density estimation approach, is used for distinguishing between natural and anthropogenic contributions of trace elements in the investigated sediments. Following the intensive industrialization of Augusta area, marine sediments reveal the severe impact of local anthropogenic activities for many elements (e.g. As, Cd, Hg, Pb, and Sb), which are considered very dangerous for the en…

PETROGRAPHY AND GEOCHEMISTRY OF THE PIETRA DI BILLIEMI (NW SICILY, ITALY): IMPLICATIONS WITH THE GEOLOGICAL HISTORY OF JURASSIC TETHYS FROM A HYSTORIC DIMENSION STONE

The genesis of actively growing siliceous stromatolites: Evidence from Lake Specchio di Venere, Pantelleria Island, Italy

This study documents the attributes of siliceous stromatolites growing in the Lake Specchio di Venere, on the volcanic island of Pantelleria, Italy, in a setting characterized by very shallow cold waters and pools and by scattered hydrothermal activity, which exhales mainly CO2, at emission point temperatures of 34 to 58 °C. The saturation indexes indicate that the lake waters are saturated with respect to tridymite, cristobalite, chalcedony and quartz, and slightly undersaturated with respect to amorphous silica. Common roughly laminated and poorly lithified stromatolites show scanning electron microscope (SEM) evidence for silicified microbial mat structures, including biofilms, filamento…

Chemostratigraphy of the early Pliocene diatomite interval from MIS AND-1B core (Antarctica): Palaeoenvironment implications

The AND-1B drill core (1285m-long) was recovered, inside the ANDRILL (ANtarctic geological DRILLing) Program, during the austral summer of 2006/07 from beneath the floating McMurdo Ice Shelf. Drilling recovered a stratigraphic succession of alternating diamictites, diatomites and volcaniclastic sediments spanning about the last 14Ma. A core portion between 350 and 480mbsf, including a 80m-thick diatomite interval recording the early Pliocene warming event, was investigated in term of opal biogenic content and element geochemistry. Across the diatomite interval, in spite of the lithological uniformity, a fluctuating biogenic opal profile mirrors the δ18O record, testifying a decrease in prod…

87Sr/86Sr variation in Tortonian Mediterranean sediments: a record of Milankovitch cyclicity

Heavy metals in urban soils: a case study from the city of Palermo (Sicily), Italy.

Concentrations of V, Mn, Cd, Zn, Ni, Cr, Co, Cu, Pb, Hg and Sb were measured on 70 topsoil samples collected from green areas and parks in the city of Palermo (Sicily) in order to: (1) assess the distribution of these heavy metals in the urban environment; (2) discriminate natural and anthropic contributions; and (3) identify possible sources of pollution. Mineralogy, physico-chemical parameters, and major element contents of the topsoils were determined to highlight the influence of 'natural' features on the heavy metal concentrations and their distribution. Medians of Pb, Zn, Cu and Hg concentrations of the investigated urban soils are 202, 138, 63 and 0.68 mgkg(-1), respectively. These v…

Sedimentology, petrography and geochemistry of a limestone breccia (Pietra di Billiemi) from NW Sicily, Italy: implications for evolution of the Tethyan basins around the Triassic/Jurassic boundary

In this study, the Pietra di Billiemi, a famous dimension stone, is investigated because it records the tectonic evolution of the south Tethys continental margin and preserves a record of major environmental changes occurring near the Triassic/Jurassic boundary. The Pietra di Billiemi is a grey, coarse-grained and clast-supported limestone breccia cropping out in an area of the Palermo Mountains representing a segment of the Apennine–Maghrebian chain in western Sicily. The rock consists of metre-sized to centimetre-sized angular clasts, derived from Upper Triassic sponge boundstones and rudstones, with a differently coloured, silt-grained matrix. Fitted fragments are observed commonly which…

Petrographic and geochemical evidence of bacterial activity in Messinian carbonates from the Sutera section, Caltanissetta Basin, Sicily

Carbon-isotope records of the Early Jurassic (Toarcian) Oceanix Anixic Event from the Valdorbia (Umbria-Marche Apennines) and Monte Mangart (Julian Alps) sections: palaeoceanographic ans stratigraphic implications

The Toarcian oceanic anoxic event (ca 183 Ma) coincides with a global perturbation marked by enhanced organic carbon burial and a general decrease in calcium carbonate production, probably triggered by changes in the composition of marine plankton and elevated carbon dioxide levels in the atmosphere. This study is based on high-resolution sampling of two stratigraphic successions, located in Valdorbia (Umbria-Marche Apennines) and Monte Mangart (Julian Alps), Italy, which represent expressions of the Toarcian oceanic anoxic event in deep-water pelagic sediments. These successions are characterized by the occurrence of black shales showing relatively low total organic carbon concentrations (…

Mercury levels in sediments of central Mediterranean Sea: a 150+ year record from box-cores recovered in the Strait of Sicily.

To evaluate the degree of anthropogenic mercury pollution, Hg contents have been measured for box-core sediments sampled along three nearshore-offshore transects in the Strait of Sicily and well constrained for their mineralogy, bulk geochemistry and TOC%. Hg values are generally low (from 15 to 70 microg kg(-1)); however, depth profiles clearly display upcore rising concentrations (up to 202 microg kg(-1) near the SE Sicily coast) that are attributed to anthropogenic load. Based on (210)Pb chronology, these trends are more dramatic across the last 20-30 years. Geogenic influence is thought to explain some anomalies related to volcanic emission and geothermal activity. Combined effects due …

Palaeoceanographic significance of the Tethyan ‘Livello Selli’ (Early Aptian) from the Hybla Formation, northwestern Sicily: biostratigraphy and high-resolution chemostratigraphic records

High-resolution micropalaeontological and chemostratigraphic records for the Hauterivian–Aptian succession outcropping at Calabianca (NW Sicily) provide new insight into the palaeoclimatic and palaeoceanographic evolution of the Tethys Ocean. Calcareous nannofossil and planktonic foraminiferal biostratigraphy together with δ13C chemostratigraphy allowed the identification of a hiatus in the Barremian and a major one including most of the Upper Aptian, the entire Lower Albian and part of the Middle Albian. The Livello Selli equivalent was identified on the basis of lithology and well constrained by calcareous plankton biostratigraphy as well as by the δ13C curve. The multi-proxy record from …

Petrography and high-resolution geochemical records of Lower Jurassic manganese-rich deposits from Monte Mangart, Julian Alps

Deposits with unusually high Mn contents sampled at Monte Mangart in the Julian Alps include organic-rich marlstone and black shale with interbedded manganoan and siliceous limestone, which were deposited during the early Toarcian Oceanic Anoxic Event. Mn enrichment during that period has been related to global sea-level change coincident with increasing subsidence rate. The formation of Fe-Mn nodules, marking a hardground at the base of the Monte Mangart section, seems to be triggered by release of Mn from remote hydrothermal vents into a region of relatively elevated submarine topography where oxidizing conditions prevailed. However, very high Mn contents in carbonate phases above the har…

Chemical weathering of volcanic rocks at the island of Pantelleria, Italy: Information from soil profile and soil solution investigations

Abstract Concentrations of major, minor and trace elements were determined in soil profiles and soil solutions from the island of Pantelleria, Sicily Channel, to evaluate the weathering extent of soils evolved on trachytic and pantelleritic rocks and the aqueous transport of elements by their soil solutions. The chemical index of alteration (CIA) indicates a low-to-moderate degree of weathering; consistently, the mineralogical and geochemical imprints of the parent rocks are generally preserved. The chemical weathering appears to be incongruent, owing to primary minerals and glass dissolving to a variable degree while secondary minerals have formed. Based on the calculated saturation state …

Chronological records of metal deposition in sediments from the Strait of Sicily, central Mediterranean: assessing natural fluxes and anthropogenic alteration

Abstract Sediment box-cores were recovered from the Strait of Sicily along two onshore–offshore transects in water depths of 29–500 m. Samples were dated by 210 Pb and analysed for major and trace elements. Inspections of chronological profiles integrated with application of statistical algorithms to the geochemical dataset and supported by in situ hydrological observations were used to assess factors driving element distributions. Mineralogical and chemical variability of sediments offshore of the southwestern Sicily coast reflect the irregular sea floor morphology of the Adventure Bank. Anthropogenic inputs explain enrichments with respect to background values for Sb, As, Pb, and Hg, that…

Trace metal geochemistry to evaluate the use of barium as paleoproductivity indicator in a Bonarelli Level equivalent from Sicily.

Textural, chemical and isotopic variations induced by hydrothermal fluids on mesozoic limestones in northwestern Sicily

The results are given of textural and compositional investigations carried out on carbonate materials outcropping in various localities in northwestern Sicily where fluorite, barite and calcite mineralizations of hydrothermal origin occur. Observation of the textural features indicate variations in the degree of calcite recrystallization and silicification that appear to be more marked in rocks that show more evident effects of mineralization. The geochemical behaviour of the minor elements indicate variations in chemical composition (increase of Mn, Fe, and Sr and removal of Mg) as a result of interactions between mineralizing fluids and host-rocks. Comparison between the isotopic composit…

Dissolution and precipitation of gypsum and carbonate minerals in soils on evaporite deposits, central Sicily: isotope geochemistry and microfabric analysis

Abstract Soil profiles developed from carbonate- and sulphate-rich deposits of the Gessoso-Solfifera Formation (Miocene) were sampled in central Sicily (544 mm annual precipitation and a strongly seasonal rainfall regime). Carbon and oxygen isotope data supported by mineralogical and thin section investigations indicate that meteoric waters and groundwaters dissolve and repricipitate carbonates and gypsum in the soil profiles. The boundary between the C horizon and the overlying one is the formation site of 18O depleted carbonates (calcite and/or dolomite) presumably precipitated from percolating waters during wet periods. Greater δ18O values of carbonates in the shallower horizons suggest …

Isotope geochemistry of bulk carbonate from the CRP-3 drillhole, Victoria Land Basin, Antarctica.

Astronomical tuning of the Tortonian 87Sr/86Sr curve in the Mediterranean basin

This work presents a detailed 87Sr/86Sr isotope curve for the interval 7.5–9.7 Ma obtained by a high-resolution analysis (sampling spacing of about 40 kyr) of an astronomically calibrated land-based sedimentary sequence exposed in the central Mediterranean area (Gibliscemi section, southern Sicily). The main aim is to verify a synchronous response of the Mediterranean seawater Sr isotope record to the oceanic forcing on the basis of multiple comparisons of the Gibliscemi record with published coeval 87Sr/86Sr curves. A good correlation with the 87Sr/86Sr data from the ODP site 926 (equatorial Atlantic ocean), considered to be the Sr chemostratigraphic reference section for the Late Miocene,…

Chemical weathering of volcanic rocks, Pantelleria Island: information from soil profile and soil solution investigations

Concentrations of major, minor and trace elements were determined in soil profiles and soil solutions from the island of Pantelleria, Sicily Channel, to evaluate the weathering extent of soils evolved on trachytic and pantelleritic rocks and the aqueous transport of elements by their soil solutions. The chemical index of alteration (CIA) indicates a low-to-moderate degree of weathering; consistently, the mineralogical and geochemical imprints of the parent rocks are generally preserved. The chemical weathering appears to be incongruent, owing to primary minerals and glass dissolving to a variable degree while secondary minerals have formed. Based on the calculated saturation state of primar…

Contaminated sediments from dredging activities as modern turbidites: geochemical signatures in box-core sediments from the Augusta area, Ionian Sea, Sicily

The Augusta area (SE Sicily) is one of the most industrialized and contaminated coastal environments in the Mediterranean region, having a relatively high influx of unregulated industrial effluents. Valuable sets of geochemical data (major elements and trace metals), obtained from box-core sediments collected along a transect from the Sicilian coastal zone seawards of Augusta and dated via 210Pb and 137Cs, indicated increased metal contamination (notably Hg) since ca 1940-1950, related to the industrial development of the area. Metal enrichment is considerable in the coastal sediments, being significantly in excess (for Hg and Pb) of background values estimated for the Strait of Sicily. Mor…

High-resolution geochemical records of the Early Toarcian anoxic event in the Valdorbia section, Umbria-Marche Apennines, Italy

Comparative high-resolution chemostratigraphy of the Bonarelli Level from the reference Bottaccione section (Umbria-Marche Apennines) and from an equivalent section in NW Sicily: Consistent and contrasting responses to the OAE2

The Bonarelli Level (BL) from the upper Cenomanian portion of the reference Bottaccione section (central Italy) is characterized by the presence of black shales containing high TOC concentrations (up to 17%) and amounts of CaCO3 near to zero. In the absence of carbonate and, consequently, of relative carbon- and oxygen-isotopic data, the elemental geochemistry revealed to be a very useful tool to obtain information about the palaeoclimatic and palaeoceanographic evolution of the Tethys Ocean during the OAE2. Based on several geochemical proxies (Rb, V, Ni, Cr, Si, Ba), the BL is interpreted as a high-productivity event driven by increasingly warm and humid climatic conditions promoting an a…

Possible impacts of Hg and PAH contamination on benthic foraminiferal assemblages: An example from the Sicilian coast, central Mediterranean

The Palermo and Augusta urban/industrial areas (Sicily) are examples of contaminated coastal environments with a relatively high influx of unregulated industrial and domestic effluents. Three sediment box-cores were collected offshore of these urban/industrial areas in water depths of 60-150 m during two cruises (summers 2003/2004), dated by (210)Pb and (137)Cs, and analysed for total mercury concentration and total polycyclic aromatic hydrocarbon (PAH) concentration. Benthic foraminiferal assemblages were also examined (in terms of their distribution and morphology) to assess the potential use of benthic foraminifera as bioindicators of pollutant input and environmental change in these Med…

Rare earth elements in limestone/marlstone couplets from the Albian-Cenomanian Cismon section (Venetian region, northern Italy) : assessing REE sensitivity to environmental changes

Abstract We have studied the REE distribution through the Albian-Cenomanian interval of a stratigraphic succession (Cismon section, Scaglia Variegata Formation, Venetian Prealps) consisting of rhythmically alternating carbonate-rich and carbonate-poor strata which are the sedimentary expression of systematic variations of surface fertility and bottom-water redox conditions in the depositional basin. Limestone semicouplets show seawater-like shale-normalized patterns (HREE-enriched, with negative Ce anomalies and high Er/Nd ratios) indicating a clear dependence on the REE chemistry of surface seawaters. Marlstones and shales exhibit flatter patterns, more moderate Ce anomalies and low Er/Nd.…

Consistent and contrasting responses to the OAE2 in the reference Bottaccione section (Umbria-Marche Apennines) and an equivalent section in NW Sicily, Italy

Geochemistry and petrography of box-core sediments from a methane seep setting in the Strait of Sicily, central Mediterranean

The Billiemi breccia: the record of Rhaetian/lowermost Jurassic brittle deformations along the Panormide shelf edge

Sedimentary record of anthropogenic chemical and organic pollution in a Mediterranean coastal area (Gulf of Palermo, Italy).

The relatively high influx of unregulated industrial and domestic effluents has progressively degraded the Palermo coastal environment in NW Sicily. To evaluate the poorly known effects of these inputs on the Palermo Gulf, three sediment box-cores were collected along a transect perpendicular to the coast, in front of the Oreto river mouth, in water depths of 20—750 m. The samples, dated by 210Pb and 137Cs, were analysed for concentration of major/trace elements, total polycyclic aromatic hydrocarbon (PAH), total organic carbon (TOC) and for organic carbon and nitrogen isotopic compositions. Total organic carbon concentrations show relatively high values (0.4—2.9%), with a decreasing seawar…

Distribution of rare earth elements in marine sediments from the Strait of Sicily (western Mediterranean Sea): Evidence of phosphogypsum waste contamination

Concentrations of rare earth elements (REE), Y, Th and Sc were recently determined in marine sediments collected using a box corer along two onshore–offshore transects located in the Strait of Sicily (Mediterranean Sea). The REE + Y were enriched in offshore fine-grained sediments where clay minerals are abundant, whereas the REE + Y contents were lower in onshore coarse-grained sediments with high carbonate fractions. Considering this distribution trend, the onshore sediments in front of the southwestern Sicilian coast represent an anomaly with high REE + Y concentrations (mean value 163.4 lg g 1) associated to high Th concentrations (mean value 7.9 lg g 1). Plot of shale-normalized REE + …

Geochemical and sedimentological evidence of productivity cycles recorded in Toarcian black shales from the Belluno Basin, Southern Alps, northern Italy

ABSTRACT Organic-carbon-rich black shales cyclically alternating with bioturbated limestones and gray marlstones, which crop out in the Belluno Trough (Southern Alps, Italy), are expression of the early Toarcian anoxic event in the Tethys basin. Sedimentological and geochemical features such as well-developed lamination, common very small ( A negative 13C excursion at the middle part of the studied interval is correlative to maxima in TOC, V/Rb, and Ba/Rb values, identifying, within the Toarcian anoxic event, a stage of more intense bottom-water anoxia coupled with high surface fertility.

Super Sedimentological Exposures in Northwestern Sicily, Italy - From Platform Drowning and Oceanic Anoxic Events to Travertine Deposition.

Heavy metal contamination and bioproductivity record of surface sediments from the Strait of Sicily and the Ionian Sea: consequences and implication

Integrated stratigraphy of the Oligocene pelagic sequence in the Umbria- Marche basin (north-eastern Apennines, Italy): A potential Global Stratotype Section and Point (GSSP) for the Rupelian/Chattian boundary

The Oligocene represents an important time period from a wide range of perspectives and includes signifi cant climatic and eustatic variations. The pelagic succession of the Umbria-Marche Apennines (central Italy) includes a complete and continuous sequence of marly limestones and marls, with volcaniclastic layers that enable us to construct an integrated stratigraphic framework for this time period. We present here a synthesis of detailed biostratigraphic, magnetostratigraphic, and hemostratigraphic studies, along with geochronologic results from several biotite-rich volcaniclastic layers, which provide the means for an accurate and precise radiometric calibration of the Oligocene time sca…

Recent benthic foraminiferal assemblages and chemical pollution in box-core sediments from the SE Sicilian coast, Central Mediterranean.

Ba/Ca evolution in water masses of the Mediterranean late Neogene

[1] A Mediterranean composite sedimentary record was analyzed for Ba/Ca ratios on carbonate shells of Orbulina universa planktonic foraminifer (Ba/Ca)carb providing the opportunity to study and assess the extent of freshwater inputs on the basin and possible impacts on its dynamics during the Tortonian to Recent period. A number of scanning electron microscope analyses and auxiliary trace element measurements (Mn, Sr, and Mg), obtained from the same samples, exclude important diagenetic effects on the studied biogenic carbonates and corroborate the reliability of (Ba/Ca)carb ratios in foraminifera calcite as indicators of seawater source components during the studied interval. A long-term t…

Cyclostratigraphy and high-frequency carbon isotope fluctuations in Upper Cretaceous shallow-water carbonates, southern Italy

A detailed carbon isotope study has been carried out on a Santonian (Upper Cretaceous) carbonate platform succession that crops out at Monte Sant'Erasmo (southern Italy). Previous centimetre-scale studies on this succession have shown that high-frequency eustatic changes, resulting from the Earth's orbital fluctuations, controlled the hierarchical organization of the depositional and early diagenetic features in elementary cycles, bundles (groups of three to five elementary cycles) and superbundles (groups of three or four bundles). The elementary cycles, which correspond to single beds, suggest a control caused by Earth's precession; the bundles and superbundles record the short ( 100 kyr)…

Trace metal partitioning in Fe–Mn nodules from Sicilian soils, Italy

Concentrations of 20 elements (Mn, Fe, Na, Mg, Al, K, Ca, V, Co, Ni, Cu, Zn, Rb, Sr, Cd, Cs, Ba, La, Ce, Pb) were determined in 18 Fe–Mn nodules from two alfisols, which are subject to periodic waterlogging. The nodules are significantly enriched in most trace metals relative to the host soil, with Mn, Co, Ce, Pb, Ba, Cd, Ni more enriched than Fe, V, La, Cu, Sr, Zn. Cesium and rubidium show poor or no enrichment in the nodules, consistent with their aluminosilicate affiliation. Scanning electron microscopy (SEM) examination and energy dispersive X-ray spectrometer (EDS) microprobe analysis have shown different microstructures (an undifferentiated fabric and a distinctive Fe–Mn banded struct…

Transition from marine to hypersaline conditions in the Messinian Tripoli Formation from the marginal areas of the central Sicilian Basin

Abstract Three sections of the early Messinian Tripoli Formation from the northern and southern margins of the central Sicilian Basin (Serra Pirciata, Torrente Vaccarizzo, and Marianopoli) have been studied with the aim to reconstruct the sedimentary and environmental changes which occurred during the transition between marine conditions and the evaporitic events of the Salinity Crisis recorded in the overlying Calcare di Base Formation. A detailed biostratigraphic and cyclostratigraphic study provided the opportunity of cycle-by-cycle correlations between the marginal sections and the reference section of Falconara. The main paleoenvironmental changes are recorded by: (1) the evolution of …

Sedimentology and isotope geochemistry of Carnian deep-water marl/limestone deposits from the Sicani Mountains, Sicily: Environmental implications and evidence for a planktonic source of lime mud

Abstract The upper Triassic Halobia-bearing marl/limestone deposits from the Sicani Mountains (Sicily) record the sedimentary evolution of the Sicanian Basin through the middle and late Carnian time. Dark marls and interbedded grey calcilutites of Julian age are characterized by abundant pyrite, sparse bioturbation and negative carbonate carbon δ13C values. They accumulated in a basin with dominantly anoxic to dysaerobic bottom waters. Lower Tuvalian dark-grey pyritic marls and calcilutites, which contain carbonate minerals with relatively high Mn contents and widely fluctuating δ13C signatures, were deposited under dysaerobic conditions. Middle and upper Tuvalian cherty limestones show int…

Microbial dolomite associated to gypsum stromatolites from a Messinian marginal section, Madonie mountains, Sicily.

Recent benthic foraminiferal assemblages and chemical pollution in box-core sediments from the Sicilian coast, central Mediterranean

Orbitally modulated black shale deposition in the upper Albian Amadeus Segment (central Italy): a multi-proxy reconstruction

Abstract The upper Albian Amadeus Segment, which falls within Oceanic Anoxic Event 1c, exhibits cyclical alternations of marls/black shales and carbonate-rich beds that record evidence of orbital climate and sedimentary dynamics. A combined micropalaeontological (planktic and benthic foraminifera, and palynomorphs) and geochemical (stable isotopes, clay mineralogy, and major element distribution) investigation allowed recognition of a remarkable influence of continental material within the black shales. Moreover, the palaeoproductivity record is characterised by a non-linear response to the orbital forcing. The micropalaeontological and geochemical record suggests that upper Albian bedded c…

Spatial and temporal variations of mercury in Mediterranean box-core sediments, onshore-offshore Sicily

Palaeoclimatic evolution based on stable isotope geochemistry of early Oligocene to late Eocene sediments from CRP-3 drillhole, Victoria Land Basin, Antarctica

Climatic and oceanographic variations in the Holocene (1-16 ky B.P.) Mediterranean basin

Fossil microbial events in the Messinian Calcare di Base Formation from Sutera, Caltanissetta Basin, Sicily

Decoupled phosphorous and organic carbon cycles in anoxic sediments: new data from Italian Bonarelli Levels (C/T boundary).

Bulk carbonate isotope stratigraphy from CRP-3 core (Victoria Land Basin, Antarctica): evidence for Eocene–Oligocene palaeoclimatic evolution

Bulk carbonate isotope compositions and carbonate petrography from upper Eocene and lower Oligocene siliciclastic sediments of the CRP-3 sediment core (Victoria Land Basin, Antarctica) have been investigated with the aim of contributing to reconstruction of the Antarctic Cenozoic palaeoclimate. Most of the carbonate is calcite cement occurring as patches, nodules and horizons and consisting of equant and/or drusy sparry calcite, pervasive blocky calcite and rare poikilotopic calcite spar. 18O-depleted values (from −17 to −8 δ‰) of the CRP-3 carbonates suggest that the precipitating fluids were a mixing between marine and meteoric waters from melting glaciers. The δ18O record exhibits a numb…

Evidence for rapid change in Mesozoic greenhouse world: carbon records and its palaeoclimatic significance

Ancient trace of life in hypersaline environment recorded in the Messinian Calcare di Base Formation from Sutera, Caltanissetta Basin, Sicily

The key role played by the Augusta basin (southern Italy) in the mercury contamination of the Mediterranean Sea.

The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelled as a highly contaminated site. The release of mercury into the harbour seawater and its dispersion to the blue water, make the Augusta basin a potential source of anthropogenic pollution for the Mediterranean Sea. A mass balance was implemented to calculate the HgT budget in the Augusta basin. Results suggest that an average of ∼0.073 kmol of HgT is released, by diffusion, on a yearly basis, from sediments to the seawater, with a consequent output of 0.162 kmol y(-1) to coastal and offshore waters; this makes the Augusta area an important contributor of mercury to the Mediterranean Sea. Owing …

Mineralogy and geochemistry of Terra Rossa soils, western Sicily: insights into heavy metal fractionation and mobility

Abstract The distribution of heavy metals in typical Terra Rossa soils and their partitioning in specific soil phases are estimated on the basis of the comparative evaluation of bulk contents, results from sequential chemical extraction procedure (SEP) and scanning electron microscopy/energy dispersive X-ray analysis ( SEM EDX ). A general natural enrichment of heavy metals with respect to average soil is observed. Cadmium proves to be remarkably high (up to 2.4 ppm). Large amounts of Fe, Cr, Cu, Ni, Pb, and Zn occur in the ‘residual’ fraction. The results indicate selective accumulation of the heavy metals in Fe oxides, present as hematite, goethite and maghemite. There is good evidence th…

Stable carbon and nitrogen ratios (δ13Corg and δ15Ntot) of core sediments from the Gulf of Palermo (NW Sicily): implications for the carbon source

Variabilità della distribuzione spaziale e temporale dei metalli pesanti nei sedimenti recenti del Canale di Sicilia

Trace metal chemistry to evaluate the use of barium as paleoproductivity indicator in a Bonarelli Level equivalent from Sicily

Petrography and carbonate isotope stratigraphy from MIS AND-1B core, Antarctica: Evidence of the early Pliocene warming event

Abstract A large portion of ANDRILL (ANtarctic geological DRILLing) core AND-1B recovered in the Western Ross Sea and spanning the early Pliocene has been investigated in order to obtain a detailed carbonate isotope record from Antarctic margin sediments through the early Pliocene warming event. Petrographic observations and mineralogical analyses reveal the authigenic nature of the carbonate and small proportions of Fe and Mg incorporated within the calcite lattice. High productivity conditions testified by ~ 80 m-thick diatomite interval (383 to 460 mbsf) well fit with the composite nature of the authigenic carbonate generally characterizing organic matter-rich sediments. As is known, sed…

Influence of inheritance and pedogenesis on heavy metal distribution in soils of Sicily, Italy

Abstract The recognition of the potential health hazards associated with heavy metals has focused attention on the levels and behaviours of these elements both in natural and contaminated environments. Various soil types developed from different parent materials in Sicily, Italy, have been analysed in order to compare heavy metal distribution under different geopedological conditions. Total metal concentrations, metal partitioning and distribution profiles are discussed in relation to the inheritance factor and pedogenic processes. Parent material composition largely influences the contents of heavy metals in most of the analysed soils, mainly differentiating pedons for their metal concentr…

Phosphogenesis in the Bonarelli Level from northwestern Sicily, Italy: petrographic evidence of microbial mediation and related REE behaviour

Phosphogenesis at the base of the Bonarelli Level from the Calabianca stratigraphic section (northwestern Sicily) was investigated using X-ray diffraction, scanning electron microscopy, X-ray fluorescence, and stable-isotope mass spectrometry. The anoxic event onset is marked by high P(2)O(5tot) concentrations related to the presence of authigenic carbonate-fluorapatite. This mineral is poorly crystallized and occurs in three different forms: (i) fish debris locally showing evidence of re-crystallization, (ii) phosphatically cemented layers, and (iii) dense aggregates of microcrystals. Petrographic features are indicative of a microbial genesis for the carbonate-fluorapatite. Conversely, th…

Carbonate stromatolites from a Messinian hypersaline setting in the Caltanissetta Basin, Sicily: petrographic evidence of microbial activity and related stable isotope and REE signatures

Lower Messinian stromatolites of the Calcare di Base Formation at Sutera in Sicily record periods of low sea-level, strong evaporation and elevated salinity, thought to be associated with the onset of the Messinian Salinity Crisis. Overlying aragonitic limestones were precipitated in normal to slightly evaporative conditions, occasionally influenced by an influx of meteoric water. Evidence of bacterial involvement in carbonate formation is recorded in three dolomite-rich stromatolite beds in the lower portion of the section that contain low domes with irregular crinkly millimetre-scale lamination and small fenestrae. The dominant microfabrics are: (i) peloidal and clotted dolomicrite with c…

A MILANKOVITCH CLIMATE CONTROL ON THE MIDDLE MIOCENE MEDITERRANEAN INTERMEDIATE WATER.

The marly sediments of the Blue Clay Formation in the upper part of the Middle Miocene Ras il-Pellegrin composite section (Malta island, central Mediterranean) have been investigated by integrated analysis of benthic microfauna and planktonic and benthic oxygen isotopes. The astronomical calibration of the whole section, obtained by using the astronomical solution of Laskar et al. (1993), indicates for deposition of the analysed sediments a time interval ranging between 13.75 and 12.32 Ma (Sprovieri et al., 2002). This time interval is useful to investigate the oceanographic evolution of the (paleo)Mediterranean after the interruption of communications between the Mediterranean and Indo-Pac…

Sources and timing of anthropogenic pollution in two areas of the Sicilian coast, central Mediterranean

Cenomanian–Turonian carbonate and organic-carbon isotope records, biostratigraphy and provenance of a key section in NE Sicily, Italy: Palaeoceanographic and palaeogeographic implications.

In eastern Sicily, a series of highly organic-rich black shales occur as exotic blocks (~ 100 m across) floating in tectonized sediments (Argille Varicolori Unit containing olistoliths of Cretaceous-Palaeogene age). A 19-metre section, through one of these blocks near the town of Novara di Sicilia, includes cyclically bedded black shales, marlstones and claystones, which have been dated using planktonic foraminiferal and nannofossil biostratigraphy. On this basis, the section is assigned to the latest Cenomanian and clearly represents a manifestation of the Oceanic Anoxic Event characteristic of that interval. Total organic-carbon values range up to 23% and the relatively high hydrogen indi…

High-resolution geochemical and biotic records of the Tethyan 'Bonarelli Level' (OAE2, latest Cenomanian) from the Calabianca-Guidaloca composite section, northwestern Sicily, Italy

Abstract High-resolution micropalaeontological and chemostratigraphic records for the upper Cenomanian portion of the Calabianca–Guidaloca composite section (NW Sicily) provide new insight into the palaeoclimatic and palaeoceanographic evolution of the Tethys Ocean. The Bonarelli Level equivalent was identified on the basis of lithology and well constrained by calcareous plankton biostratigraphy and radiolarian assemblages, as well as by the δ 13 C curve showing a marked positive excursion (up to 4.7‰). The Bonarelli Level equivalent deposition is characterized by highly eutrophic conditions as testified by radiolarian proliferation. Black shale samples from the Calabianca–Guidaloca composi…

Analysis of the relationship between chemistry composition and stable isotope signals in coastal sediments: a biogeochemistry study to assess the environmental impact

(Table 1) Trace element/Ca ratios of Orbulina universa shells from late Neogene Mediterranean samples

A Mediterranean composite sedimentary record was analyzed for Ba/Ca ratios on carbonate shells of Orbulina universa planktonic foraminifer (Ba/Ca)carb providing the opportunity to study and assess the extent of freshwater inputs on the basin and possible impacts on its dynamics during the Tortonian to Recent period. A number of scanning electron microscope analyses and auxiliary trace element measurements (Mn, Sr, and Mg), obtained from the same samples, exclude important diagenetic effects on the studied biogenic carbonates and corroborate the reliability of (Ba/Ca)carb ratios in foraminifera calcite as indicators of seawater source components during the studied interval. A long-term trend…

Soil solution geochemistry in the Pantelleria island: implications for weathering on volcanics

A geochemical comparison between OAE2 (Cretaceous) and Sapropel S1 (Holocene)