Assessing the effect of chromium pollution on benthic foraminiferal community: morphological vs. environmental metabarcoding approaches

The purpose of this experimental study is to assess the impact of different concentrations of chromium (Cr) through time on the diversity of cultured benthic foraminifera combining two morphological approaches for the identification of living specimens that are Rose Bengal (RB) staining and CellTracker Green (CTG) labelling as well as environmental DNA and RNA metabarcoding. Seven tanks/aquaria with different concentrations of Cr in water, namely 100 ppt, 1 ppb, 10 ppb, 100 ppb, 1 ppm and 10 ppm plus the control were used. A mesocosm was extracted from each tank at pre-established time (1 week, 2 weeks, 4 weeks 6 weeks and 8 weeks). Morphological analyses produced 6 datasets based on staini…

The response of cultured meiofaunal and benthic foraminiferal communities to lead exposure: Results from mesocosm experiments

Lead (Pb) has been regarded as a very toxic element that poses a serious threat to biota. A mesocosm experiment is performed to assess the influence of Pb on meiofaunal (metazoans within 45-500 µm) and benthic foraminiferal (protozoans) communities. To this end, sediments bearing such communities are incubated in mesocosms, exposed to different levels of Pb in seawater, and monitored for up to eight weeks. Concentrations of Pb below 1 ppm in water do not promote a significant increase of this metal in sediments. Relatively high concentrations of Pb seem to affect meiofaunal and benthic foraminiferal communities by reducing their richness or diversity, and the abundance of the most sensitive…

Onset of the Messinian Salinity Crisis: Sedimentological, petrographic and geochemical characterization of the pre-salt sediments from a new core (Caltanissetta Basin, Sicily)

The present study aims to reconstruct the environmental changes leading to the Messinian Salinity Crisis during the transition from the Tortonian-Messinian marine conditions to the Messinian evaporitic environments. The core 3AGN2S04, recently drilled in the Caltanissetta Basin (Sicily), was analyzed to reveal the petrographic, mineralogical and geochemical characteristics of the late Tortonian – early Messinian pre-salt sediments. In particular, the facies characterization of the carbonates and organic-rich shales of the Calcare di Base (CdB) member allowed to understand its significance in the paleoenvironmental evolution towards salt deposition and to the reconstruct the brecciation proc…

Microbial role in dolomitic crust formation associated to Messinian gypsum, Monte Conca cave, Sicily.

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

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

Premature aging in bone of fish from a highly polluted marine area

Fish species have attracted considerable interest in studies assessing biological responses to environmental contaminants. In this study, the attention has been focussed on fishbone of selected fish species from a highly polluted marine area, Augusta Bay (Italy, Central Mediterranean) to evaluate if toxicant elements had an effect on the mineralogical structure of bones, although macroscopic deformations were not evident. In particular, an attempt was made to evaluate if bone mineral features, such as crystallinity, mineral maturity and carbonate/phosphate mineral content, determined by XR-Diffraction and FT-IR Spectroscopy, suffered negative effects due to trace element levels in fishbone,…

Quantifying OAE2 marine oxygen levels from coupled Mo and U isotopes: A Tethyan perspective.

U and Mo isotopes are promising geochemical proxies for globally averaged ocean redox conditions in deep time. Because the Mo and U isotope compositions of seawater are controlled primarily by variation in ocean redox conditions, coupled Mo and U isotope records can be used to reconstruct variation in the relative sizes of oxic/suboxic, anoxic and euxinic sinks over geological time. The different sensitivities of Mo and U to anoxic and euxinic conditions creates a situation in which joint evaluation of the Mo and U isotope records provide greater constraints on variation in ocean redox conditions than either proxy can in isolation. Here we report new and published Mo- and U-isotope data fro…

Caratterizzazione chimica ed isotopica della carota MSK-C4 (Tirreno Meridionale)

Biostratigraphy and isotope stratigraphy of upper Maastrichtian–Danian marine deposits of the Kopet-Dagh Basin, northeast Iran

Abstract Biostratigraphy, using foraminifera and echinoids, plus high-resolution carbon isotope stratigraphy of the upper Maastrichtian–Danian interval in the western part of the Kopet-Dagh Basin in northeast Iran are outlined. Our study of shallow-marine carbonate platform deposits of the Kalat Formation, rich in larger benthic foraminifera (predominantly Clypeorbis mammillatus Schlumberger, Lepidorbitoides sp. and Siderolites calcitrapoides Lamarck), has allowed the definition of a C. mammillatus-S. calcitrapoides Assemblage Zone, of late Maastrichtian age. Clypeorbis mammillatus is here recorded for the first time from the Maastrichtian Kalat Formation and represents the most easterly fi…

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

Ricostruzione paleoclimatica degli ultimi 11.200 anni tramite lo studio di una carota di sedimento prelevata nell’offshore del Golfo di Palermo (Tirreno Meridionale)

Il presente lavoro riguarda lo studio di una carota di sedimento della lunghezza di 196 cm, prelevata nell’offshore del Golfo di Palermo (Tirreno Meridionale) ad una profondità di 990 m durante la campagna oceanografica PUMA 09 (MaGIC 2009). La carota è stata campionata ogni 2 cm e su ciascun campione sono state effettuate analisi sedimentologiche, micropaleontologiche (foraminiferi planctonici) e geochimiche (δ13C e δ18O). Le analisi degli isotopi stabili sono state effettuate sui gusci di Globigerinoides ruber. Le analisi granulometriche hanno evidenziato che i sedimenti sono costituiti da argille e argille siltose di colore grigio-bruno, con percentuali di fango superiori al 90%, mentre …

Quantitative identification, distribution and source apportionment of anthropogenic trace metals in marine sediment of Milazzo gulf (N-E Sicily): preliminary results

The influence of high pCO2 on otolith shape, chemical and carbon isotope composition of six coastal fish species in a Mediterranean shallow CO2 vent

Naturally acidified environments, such as CO2 vents, are important sites to evaluate the potential effects of increased ocean acidification on marine ecosystems and biota. Here we assessed the effect of high CO2/low pH on otolith shape and chemical composition of six coastal fish species (Chromis chromis, Coris julis, Diplodus vulgaris, Gobius bucchichi, Sarpa salpa, Symphodus ocellatus) in a Mediterranean shallow CO2 vent. Taking into consideration the major and trace elements found near the vent and the gradient of dissolved inorganic carbon, we compared the otolith chemical signatures of fish exposed long-term to elevated CO2 emissions and reduced pH (mean pH 7.8) against fish living in …

The role of biotic and abiotic processes in the origin of Messinian evaporate-associated carbonates (Southern Italy)

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

Evidences on alterations in skeleton composition and mineralization in a site-attached fish under naturally acidified conditions in a shallow CO2 vent

Abstract Background Ocean acidification may affect fish mineralized structures (i.e. otoliths and skeleton). Methods Here, we compared the elemental composition of muscle and skeleton and the mineral features of skeleton in the site-attached fish Gobius bucchichi naturally exposed to high pCO2/low pH conditions in a shallow CO2 vent with fish of the same species exposed to normal pH. Results Overall, no skeleton malformations were found in both pH conditions, but among-site differences were found in the elemental composition. Interestingly, higher Ca/P values, inducing a moderate skeleton maturation, were found in fish exposed to acidified conditions than in controls. Conclusion Our finding…

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…

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…

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…

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

Chemical, mineralogical and isotopic observations on hypersaline surficial deposits from Trapani evaporation ponds.

Distribution of Cr and Pb in artificial sea water and their sorption in marine sediments: an example from experimental mesocosms

The uptake of two heavy metals (chromium and lead) in sediments in experimental mesocosms under exposure to different metal concentrations was evaluated by monitoring their concentrations over time both in seawater and in sediment. Two separate experiments under laboratory-controlled conditions were carried out for the two metals. Sediments were collected from a protected natural area characterized by low anthropic influence and were placed in mesocosms that were housed in aquaria each with seawater at a different metal concentration. At pre-established time intervals, seawater and sediment samples were collected from each mesocosm for chemical analyses. Quantification of chromium and lead …

La Grotta dei Personaggi di Montevago (AG), una nuova segnalazione di cavità ipogenica in Sicilia

La Grotta dei Personaggi è localizzata in Sicilia occidentale, nei pressi di Monte Magaggiaro, a S del centro abitato di Montevago (AG). Nell’area sono presenti sorgenti termali, caratterizzate da acque cloro-solfate alcalino-terrose con temperatura di circa 40 °C e pH 7. La Grotta dei Personaggi, conosciuta già dai primi anni del 1900 e nota anche per ritrovamenti archeologici, non era mai stata dettagliatamente rilevata e studiata. La cavità si sviluppa prevalentemente in calcari di piattaforma della formazione Inici (Giurassico inf.) e in calcari di scarpata e pelagici della formazione Buccheri (Giurassico inf.-sup.). Si tratta di una cavità sub-orizzontale che presenta uno sviluppo di c…

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…

The Oceanic Anoxic Event 2 in Western Tethys: Palaeoenvironmental and palaeoclimatic recostruction by high-resolution records of geochemical markers.

Ricostruzione paleoclimatica degli ultimi 16.000 anni nella carota MSK12-C1 (Tirreno Meridionale)

Benthic foraminiferal response to trace element pollution. The case study of the Gulf of Milazzo, NE Sicily (Central Mediterranean Sea).

The response of benthic foraminiferal assemblages to trace element pollution in the marine sediments of the Gulf of Milazzo (north-eastern Sicily) was investigated. Since the 1960s, this coastal area has been a preferred site for the development of two small marinas and a commercial harbour as well as for heavy industry. Forty samples collected in the uppermost 3-4 cm of an undisturbed layer of sediment in the littoral environment were used for this benthic foraminiferal analysis. The enrichment factors (EFs) of selected trace elements (As, Co, Cr, Cu, Mn, Ni, Pb and Zn) were also calculated. Changes both in benthic foraminiferal assemblages and in some trace elements concentrations have pr…

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

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

Il Grigio di Billiemi

Un peculiare itinerario geo-turistico nella Sicilia occidentale: dall’oceano anossico Mesozoico al Moscato di Pantelleria.

Petrographic and geochemical characterization of the Middle‒Upper Jurassic Fe–Mn crusts and mineralizations from Monte Inici (north-western Sicily): genetic implications

AbstractFe–Mn concretions and mineralizations, associated with condensed horizons and hardground, are significant archives in ancient carbonate rocks. Their petro-chemical study allows an assessment of the palaeoenvironmental context in which they were formed also connected to their biotic or abiotic origin. At the western side of the Monte Inici (Fornazzo section, north-western Sicily) a well exposed outcrop of condensed pelagic limestones (Rosso Ammonitico facies: Middle‒Upper Jurassic) is well-known and thoroughly studied. In this section, the base of the Rosso Ammonitico facies consists of a very condensed level rich in fossils with a variable thickness deposited from the early Bathonia…

Benthic foraminifera as indicators of relative sea-level fluctuations: Paleoenvironmental and paleoclimatic reconstruction of a Holocene marine succession (Calabria, south-eastern Tyrrhenian Sea)

This study presents the results of an integrated stratigraphic analysis conducted on a marine gravity core (MSK-12 C4) recovered from the outer continental shelf (82 mwater depth) of western Calabria, ~2.6 km, NE of Capo Vaticano (Eastern Tyrrhenian margin). The gravity core MSK-12 C4 recovered a stratigraphic succession of 4.18 m beneath the seafloor representing the last ~11.1 ka. Sedimentological analysis, micropaleontological quantitative analysis on benthic foraminiferal assemblages, tephrostratigraphy, sequence stratigraphic analysis of high resolution reflection seismic data recorded in the core site area and AMS 14C absolute age determinations allowed reconstructing the marine recor…

Dall'ambra siciliana al Tecnezio - Storia per un Museo di Mineralogia

The Caribbean Plateau and OAE2: Resolution of timing and trace metal release

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

The Messian Salinity Crisis and the catastrophic Zanclean flooding of the dessicated Mediterranean: the Red Sea record

Hatching Success of Caretta caretta on a Mediterranean Volcanic Beach: Impacts from Environmental Parameters and Substrate Composition

New data on the potential impact of environmental parameters and the mineralogical nature of the substrate on the hatching success of the loggerhead sea turtle Caretta caretta on a volcanic beach on Linosa Island in the central Mediterranean Sea are reported. During 2 years of investigation (2018-19), five nests were observed. The temperature and moisture of the nests were determined along with the grain size and mineralogical nature of the substrate. The temperature values of the nests recorded at depths of 5 and 35 cm showed an average temperature incubation of 32.2°C ± 1.4°C and 32.8°C ± 1.6°C, respectively, with peaks close to 37°C. The sedimentological analysis carried out on two cores…

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

Paleoceanographic and paleoenvironmental changes in the Red Sea during the Messinian/Zanclean: new data from Site 225.

Geochimica e petrografica di black shales del Livello Bonarelli, sezione di Novara di Sicilia (Monte Peloritani), Sicilicia nord-orientale: Implicazioni paleoambientali

Black shales ad alto potenziale petrolifero, alternati ritmicamente a marne e argilliti, affiorano in associazione con Argille Varicolori (Cretaceo-Paleogene) nei pressi di Novara di Sicilia (Monti Peloritani, Sicilia nord-orientale) costituendo l’espressione sedimentaria di un evento anossico con diffusione globale (OAE2), riferibile al Cenomaniano superiore. I depositi corrispondenti a tale evento sono individuati come “Livello Bonarelli”. In detta successione, le alternanze black shales-marne-argilliti si estendono per uno spessore di circa 11 metri passando verso il basso ad alternanze irregolari di calcari marnosi, marne chiare, marne scure, argilliti e calcareniti (spessore ca. 9 m) c…

Planktonic foraminifera biozones and isotope stratigraphy of the Cenomanian-Turonian boundary in the western part of the Kopet-Dagh Basin, NE Iran

Abstract A biostratigraphic study based on the planktonic foraminifera and isotope stratigraphy of the Cenomanian-Turonian interval has been undertaken in the western part of the Kopet-Dagh Basin (NE Iran). In this research, two stratigraphic sections including: Maraveh Tappeh and Qareh Galdy have been sampled and studied. Based on planktonic foraminifera, three biozones were assigned to this interval. These are the Rotalipora cushmani Zone, Whiteinella archaeocretacea Zone and Helvetoglobotruncana helvetica Zone, These biostratigraphic data confirm a gradual faunal turnover of planktonic foraminifera, at the Cenomanian-Turonian boundary in Whiteinella archaeocretacea Zone characterized by:…

Assessing the effect of mercury pollution on cultured benthic foraminifera using DNA metabarcoding and morphological approaches

Heavy metals such as mercury (Hg) occur in ecosystems from both natural sources and human activities, with large variations in concentrations and pose a significant health hazard through bioaccumulation and biomagnification. The aim of this experimental study is to assess the impact of different concentrations of Hg through time on the diversity of cultured benthic foraminifera. Tanks with concentrations of Hg up to 100 ppm were considered. Mesocosms containing 1-cm-thick sediment from each tank were subsampled at pre-established time intervals for geochemical (Hg content), morphological and molecular analyses. Morphological analyses were based on both Rose Bengal and the CellTracker Green …

Sul ritrovamento di tephra di composizione riolitica peralluminosa a largo del promontorio di Capo Vaticano (Calabria Occidentale, Tirreno Meridionale)

Textural features and isotope geochemistry of the Scillato travertine (north-central Sicily): genetic implications.

The travertine deposit, outcropping near the Scillato town (north-central Sicily), was originated by precipitation of calcium carbonate from the Scillato springs, documented as bicarbonate-enriched waters due to dissolution of the Madonie mountains carbonate rocks. This deposit is today well represented by the Travertine Cave, essentially constituted by stalactites and stalagmites in which travertine typically appears laminated with alternation of light and dark laminae. Mineralogical analysis have revealed the almost exclusive presence of calcite and observation under the polarized-light microscope showed different textural features, like presence of debris and porous portions, micritic po…

Scienze Naturali

Il corso è stato progettato per disporre di tutti gli argomenti previsti da programma ministeriale per il quinto anno dei Licei (Chimica organica, Genetica, Biochimica, Microbiologia, Biotecnologie e Scienze della Terra) in un unico volume. Gli argomenti proposti sono trattati in maniera organica, evidenziando i possibili punti di contatto tra le differenti discipline e abituando lo studente a sviluppare una concezione liquida del sapere. La didattica e la struttura proposte sono finalizzate alla conoscenza e alla comprensione dei fenomeni che contraddistinguono la materia, la natura, gli esseri viventi e l’uomo e l’ambiente nel quale vive e col quale interagisce. Il corso concorre alla cos…

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

Turonian-Maastrichtian biostratigraphy and isotope stratigraphy of the Kopet-Dagh Basin deposits, northeastern Neo-Tethys, Iran

Abstract Planktonic foraminiferal biostratigraphy and isotope stratigraphy analyses of Turonian-Maastrichtian deposits have been carried out in the western part of the Kopet-Dagh Basin. The identification of the planktonic foraminiferal assemblages has led to the recognition of twelve Upper Cretaceous zones (Helvetoglobotruncana helvetica Zone to the Contusotruncana contusa-Abathomphalus mayaroensis zone) from the Tethyan realm. The obtained stable carbon isotope profile correlates with other reference curves, revealing many Late Cretaceous events including the Hitchwood, Navigation, Light Point, East Cliff, White Fall, Late Campanian Event (LCE), Campanian-Maastrichtian Boundary Event (CMB…

Assessing the effect of mercury pollution on cultured benthic foraminifera community using morphological and eDNA metabarcoding approaches

Mercury (Hg) is a highly toxic element for living organisms and is known to bioaccumulate and biomagnify. Here, we analyze the response of benthic foraminifera communities cultured in mesocosm and exposed to different concentrations of Hg. Standard morphological analyses and environmental DNA metabarcoding show evidence that Hg pollution has detrimental effects on benthic foraminifera. The molecular analysis provides a more complete view of foraminiferal communities including the soft-walled single-chambered monothalamiids and small-sized hard-shelled rotaliids and textulariids than the morphological one. Among these taxa that are typically overlooked in morphological studies we found poten…

Microbial-mediated pre-salt carbonate deposition during the Messinian salinity crisis (Calcare di Base fm., Southern Italy)

Abstract A multi-scale analysis of sedimentary carbonate facies and post-sedimentary diagenetic features of the Calcare di Base Formation, the precursor to evaporites in Upper Messinian successions of Northern Calabria and Central Sicily, has revealed their microbial bio-mediated origin. Massive to laminated microbial boundstones represent the most common sedimentary facies forming flat to low relief cm to m scale stromatolitic and thrombolitic bodies. The fabric of the micrite varies from peloidal to aphanitic, and almost always preserves filamentous bacteria which characterized the original microbial mat. The mat was dominated by sulphur-oxidizing bacteria belonging to the Thiotrichaceae,…

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

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

Guano-related phosphate-rich minerals in European caves

International audience; Guano is a typical deposit found in caves derived from the excretions of bats and in minor cases of birds. These organic deposits decompose and form a series of acid fluids and gases that can interact with the minerals, sediments, and rocks present in the cave. Over sixty phosphates are known and described from caves, but guano decay also often leads to the formation of nitrates and sulfates. In this study twenty-two European caves were investigated for their guano-related secondary minerals. Using various analytical techniques, seventeen phosphates, along with one sulfate (gypsum), were recognized as secondary products of guano decay. Among those minerals, some are …

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…

Carbon-isotope record and palaeoenvironmental changes during the early Toarcian oceanic anoxic event in shallow-marine carbonates of the Adriatic Carbonate Platform in Croatia

AbstractGeochemical (δ13C, δ18O and Mn) compositions of Lower Jurassic shallow-water carbonates cropping out in Croatia were analyzed to elucidate the impact of the early Toarcian oceanic anoxic event (T-OAE) on the Adriatic Carbonate Platform (AdCP). The bulk-rock carbon-isotope records through the studied sections (Velebit-A, Velebit-B and Gornje Jelenje) are characterized by two significant excursions: (i) an initial positive trend interrupted by a pronounced negative shift (c. 2.5‰) that is followed by (ii) an increasing trend of positive values (up to 4.5‰). A comparison with δ13C trends obtained from well-calibrated sections from other localities in Europe shows that the overall chara…

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…

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…

Relazione tra le associazioni a foraminiferi bentonici e l'inquinamento da elementi in traccia nel Golfo di Milazzo, N-E Sicilia (Tirreno Meridionale)

Ricostruzione paleoambientale e paleoclimatica mediante foraminiferi bentonici di un settore dell'offshore di Capo Vaticano (Tirreno Meridionale)

Seepage carbonate mounds in Cenozoic sedimentary sequences from the Las Minas Basin, SE Spain

Abstract A number of carbonate mounds composed of indurate, strongly folded and/or brecciated calcite and dolomite beds occur interstratified in Cenozoic sedimentary sequences from the Las Minas Basin. Part of the fabric of the rock forming the carbonate mounds is composed of laminated to banded dolostone similar to the host rock but showing contrasted lithification. Moreover, the carbonate deposits of the mounds display aggrading neomorphism of dolomite, partial replacement of dolomite by calcite, calcite cementation, and extensive silicification, locally resulting in box-work fabric. Eight main lithofacies were distinguished in the carbonate mound deposits. In some lithofacies, chert is p…

Benthic foraminifera as an innovative proxy for pollution monitoring, impact and risk assessment of marine ecosystems: experimental studies to evaluate the effect of trace element and oil pollutions

Granulometry, mineralogy and trace elements of marine sediments from the Gulf of Milazzo (NE Sicily): evaluation of anthropogenic impact

Granulometry, mineralogy, and trace element concentrations are determined in marine sediments from thirty-six sampling sites in the littoral environment of the Gulf of Milazzo (NE Sicily). Sediment samples were collected in August 2008, along 18 seaward transects, at water depths of ‐10, ‐20 and ‐30 m, by using a Van Veen grab. Grain-size analysis shows predominance of sand (56%) and silt (35%) fractions with respect to clay (7%) and gravel (2%) fractions. Bulk mineralogical analysis documents the presence of quartz, micas, feldspars, calcite, and chlorite, which reflect erosion processes affecting the Kabilian-Calabrian Units. Concentrations of most trace elements in the deeper sediments w…

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