Rodolfo Coccioni | Università di Urbino "Carlo Bo" (original) (raw)

Papers by Rodolfo Coccioni

Tectonics, 1994

During the Tertiary Period, the northeastern Apennines of Italy functioned as a quiet depositiona... more During the Tertiary Period, the northeastern Apennines of Italy functioned as a quiet depositional basin for fine-grained, volcanic ashfalls from distant explosive volcanism accompanying the Alpine/Apennine orogenesis. These ashes have been dated by several authors with different radioisotopic methods in the past decade (K/At, 4øAr/S9Ar, and Rb/Sr on biotite separates; 4øAr/39Ar single-crystal laser fusion on plagioclase and sanidine; and U/Pb on zircon) and provide the means for a precise, accurate age calibration of the Tertiary magnetostratigraphic and biostratigraphic timescales. However, the provenance of these tephras has remained uncertain. To resolve this problem, we have carried out detailed grain size analysis of the so-called "Livello Raffaello," a feldspar-bearing bentonite recognized in numerous outcrops throughout the region at the very base of the Aquitanian to Burdigalian Bisciaro formation. The Raffaello, stratigraphically located in the upper part of planktonic foraminiferal Zone N4 and calcareous nannofossil Zone NN1, upper Chron 6A-r (middle Aquitanian), yielded an isochron age of 21.2 _ 0.5 Ma (2(5) from 27 4øAr/39Ar dates by laser fusion on plagioclase. We measured the mean grain size M• of the >63-gm felsic fraction (i.e., feldspar and quartz) of the Raffaello in 11 representative outcrops in the region and compared the grain size against distance from two possible volcanic sources; the Venetian province (northern provenance) and the Sardinian province (western provenance). While the Venetian source shows no distinct trend of the MtI, distribution, the Sardinian plot exhibits a very clear linear grain size decrease with distance. After having tentatively established a Sardinian source (no other volcanoes of Aquitanian age are known west of the Apennine basin), we revised the M• distribution through palinspastic restoration, including the post-Aquitanian anticlockwise rotation of the Sardinian microplate and consequent orogenic shortening of the northeastern Apennine fold-andthrust belt. For this we have used the "thick-skinned" model of Lavecchia et al. (1984), which envisions a shortening for the northeastern Apennines of 3 to 30 km, and the "thin-skinned" model of (Bally et al., 1986), which assumes a variable shortening of 50 to 250 km. We have also modeled the distribution of the MtI, of felsic crystals for modern analogue stratospheric westerly winds blowing in this region from fall to spring at speeds of 10 to 30 m/s and altitudes ranging from 25 km to 40 Paper number 94TC00295. 027 8-7407/94/94TC-00295510.00

Earth and Planetary Science Letters, 2004

High-resolution studies (d 13 C, d 18 O, and elemental abundances) were done in rocks at and belo... more High-resolution studies (d 13 C, d 18 O, and elemental abundances) were done in rocks at and below the GSSP for the Eocene/ Oligocene (E/O) boundary at Massignano, Italy. In addition to an earlier known Ir anomaly at 5.61 m, which is possibly linked to the Popigai impact event, we confirm the presence of two additional Ir anomalies in the intervals from 6.00 to 6.40 m and from 10.00 to 10.50 m, with maximum values of 259 F 32 ppt at 6.17 m, and 149 F 24 ppt at 10.28 m, respectively. The lower Ir anomaly might be derived from the Chesapeake Bay impact event, whereas for the other one no impact event is known. Similar d 13 C and d 18 O trends related to the two Ir anomalies indicate that the Ir anomaly at 10.28 m might be also derived from an impact into a continental shelf, similar to the Chesapeake Bay impact event. d 18 O values decrease in the high Ir layers to À 1.16x and À 1.17x, respectively, which, together with the negative shifts in d 13 C in the Ir-rich levels, indicate a warm pulse superimposed on a general Late Eocene cooling trend that is characterized by d 18 O values ranging between À 0.6x and À 0.4x. The release of methane hydrate after an impact in a continental shelf or seafloor, or impacts of 12 C-rich comets during a 2.2-million-year-long comet shower, respectively, could produce these more negative carbon and oxygen excursions compared to the continuously decreasing trend over the whole Late Eocene Massignano section. D

Earth and Planetary Science Letters, 2008

The prelude to the second global oceanic-anoxic event of the Cretaceous (OAE 2), as recorded in t... more The prelude to the second global oceanic-anoxic event of the Cretaceous (OAE 2), as recorded in the classic sections of the Scaglia Bianca Formation in the Umbria-Marches region of Italy, is characterized by an oscillation between black to gray, organic-rich cherts and white pelagic limestones. Spectral analysis of these lithologic alternations reveals a robust set of cycles whose periods are remarkably similar to the orbital cycles calculated by Laskar et al. [Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., Levrard, B., 2004, A long term numerical solution for the insolation quantities of the Earth. Astronomy and Astrophysics, 428, 261-285.]. Bandpass filtering shows that the 140-80 kyr signal approximates the envelope of the 26-16 kyr signal, just as expected if these components represent responses to orbital eccentricity and precession. Matching the presumed eccentricity signal to the theoretical eccentricity of Laskar et al. yields an age for the base of the Bonarelli Level (onset of OAE 2 in Italy) of 94.21 Ma (93.72 Ma provides an alternative)

Earth and Planetary Science Letters, 2001

A nearly complete and undisturbed Miocene carbonate sequence is present in the easternmost part o... more A nearly complete and undisturbed Miocene carbonate sequence is present in the easternmost part of the Umbria-Marche basin, Italy, which is ideal for detailed and integrated stratigraphic investigations of the Miocene Epoch. In this study, we were trying to obtain evidence for ...

Marine Pollution Bulletin, 2009

In order to assess the response of benthic foraminifera to trace element pollution, a study of be... more In order to assess the response of benthic foraminifera to trace element pollution, a study of benthic foraminiferal assemblages was carried out into sediment samples collected from the Santa Gilla lagoon (Sardinia, Italy). The lagoon has been contaminated by industrial waste, mainly trace elements, as well as by agricultural and domestic effluent. The analysis of surficial sediment shows enrichment in trace elements, including Cr, Cu, Hg, Ni, Pb and Zn. Biotic and abiotic data, analyzed with multivariate techniques of statistical analysis, reveal a distinct separation of both the highly polluted and less polluted sampling sites. The innermost part of the lagoon, comprising the industrial complex at Macchiareddu, is exposed to a high load of trace elements which are probably enhanced by their accumulation in the finer sediment fraction. This area reveals lower diversity and higher percentages of abnormalities when compared to the outermost part of the lagoon.

Estuarine Coastal and Shelf Science, 2008

Benthic foraminifera are increasingly used as environmental bio-indicators of pollution in coasta... more Benthic foraminifera are increasingly used as environmental bio-indicators of pollution in coastal and marginal marine settings. Their community structure provides information on the general characteristics of the environment and some species are sensitive to specific environmental parameters. Among various criteria, the occurrence of test abnormalities may represent a useful bioindicator for monitoring environmental impacts in coastal regions. A study of living benthic foraminifera was carried out in 42 sediment samples collected from the central Adriatic coast of Italy. Benthic foraminiferal assemblages from this area are rich, well preserved, and dominated by Ammonia parkinsoniana, and subordinately by Ammonia tepida, Aubignyna perlucida, Eggerella scabra, and Nonionella turgida. Heavy metal concentrations have been analysed which indicate low polluted environmental conditions. Foraminiferal species and heavy metal concentrations were investigated both with bivariate (correlation matrix) and multivariate techniques of principal component analysis (PCA) and cluster analysis. Statistical analysis shows a possible control of these pollutants both on the taxonomic composition of the benthic foraminiferal assemblages and the development of test malformations. Increasing heavy metal contents lead to an increase in relative abundance of A. tepida A. perlucida, N. turgida and E. scabra, and a relative concurrent decrease in relative abundance of A. parkinsoniana and higher percentages of deformed specimens (FAI) and species (FMI). Our results confirm that A. parkinsoniana prefers clean to low polluted environments and show that it is a very sensitive and un-tolerant species to heavy metal pollution being deeply affected by heavy metal content even at low concentrations. Our findings also confirm the capacity of the A. tepida to tolerate increasing heavy metal concentrations, and highlights that A. perlucida, N. turgida and E. scabra can be considered as tolerant species at least in low polluted environments. Following this, A. parkinsoniana and A. tepida can be reciprocally considered good bioindicator of heavy metal pollution over the surveyed area. The development of test abnormalities with a variety of malformations is a noticeable feature over the study area where the living deformed assemblages are largely dominated by a few species. The low percentages of deformed specimens (Foraminiferal Abnormality Index up to 4.7, with 2 on average) match well with the low concentrations of heavy metals that lead to low polluted environmental conditions. This study confirms and supports the suitability of studying benthic foraminifera as a technique for the in situ continuous bio-monitoring of heavy metal pollution of coastal marine sediments.

Palaeogeography Palaeoclimatology Palaeoecology, 2005

... The Tethyan Bottaccione reference-section is 5.48 m thick (Fig. 2 and Fig. 3) and located in ... more ... The Tethyan Bottaccione reference-section is 5.48 m thick (Fig. 2 and Fig. 3) and located in the type-area of the BL, 1 km NE of the town of Gubbio, on the northern slope of the Bottaccione Gorge, along the road SS 298. The ...

Paleoceanography, 2006

A high-resolution pelagic bulk carbonate stable isotope record from a central Tethyan lower Creta... more A high-resolution pelagic bulk carbonate stable isotope record from a central Tethyan lower Cretaceous composite section is presented. Three well-exposed sedimentary sequences (Chiaserna Monte Acuto, Bosso, and Gorgo a Cerbara sections, central Italy) cropping out throughout the Maiolica Formation were correlated by a detailed magnetostratigraphy, lithostratigraphy, and calcareous plankton biostratigraphy in order to reconstruct a continuous composite record from the middle Berriasian to the lower Aptian. The integrated stratigraphy of the three sequences provided an accurate time framework for the new high-resolution C isotope curve which is presented in this study. The composite δ13C signal, recorded in the depth domain, was analyzed by combined Lomb-Scargle periodogram and weighted wavelet Z transform (WWZ) - weighted wavelet amplitudes (WWA) Foster wavelet spectral methodologies, both appropriate for unevenly sampled curves. These tools allowed us to unravel the main frequencies modulating the record and their hypothetical shift in depth, respectively. The long-term, ~400,000 and ~2,400,000 years, eccentricity cycles were consistently recorded throughout all the composite record. Once band-pass filtered in these two periodicity bands and compared to the lithologic pattern cycles identified throughout the composite sequence, the δ13C signal was used as a valuable proxy record for a reliable construction of an orbital tuning of the early Cretaceous. An estimated age for all the different stratigraphic events recognized throughout the composite record was reported. In particular, the reestimated ages of the paleomagnetic chrons, documented in the upper part of the record, show differences with those reported by Gradstein et al. (2004) up to ~2 m.y. The Valanginian carbon shift, present in the middle part of the composite sequence was estimated to be ~2.3 m.y. long. The good agreement between the estimated age of the base of this positive carbon isotope excursion (~136.34 m.y.) and the predominant volcanic phase associated to the Paranà-Etendeka large igneous province intrusion confirmed a possible cause-effect link between the two events.

Cretaceous Research, 1998

An integrated stratigraphic, palaeontological, and geochemical study has been carried out across ... more An integrated stratigraphic, palaeontological, and geochemical study has been carried out across the uppermost Hauterivian Faraoni Level of the Fiume Bosso section in the Umbria-Marche Apennines, Italy. This level represents a ®rst, prominent sign of the global changes that led to the widespread deposition of mid-Cretaceous organic-rich facies. Marked changes in the organic geochemical record and micro¯oral and micro-and macrofaunal assemblages occur within the interval. They are characteristic for short-term deposition in strongly dysoxic bottom conditions. Such changes probably re¯ect climatic variation which, in turn, induced variations in the palaeoceanographic regime.

Palaeogeography Palaeoclimatology Palaeoecology, 2006

Chamber elongation is a recurring morphological character in Cretaceous and Cenozoic planktonic f... more Chamber elongation is a recurring morphological character in Cretaceous and Cenozoic planktonic foraminiferal evolution suggesting that the clavate body-plan takes advantage through particular environmental conditions. Cretaceous planktonic foraminifera bearing radially elongated chambers become repeatedly a consistent component of assemblages in correspondence with the deposition of remarkable organic layers that record the effects of oceanic anoxic events (OAEs). Due to this apparent correspondence, chamber elongation has been recently interpreted as an adaptation to low oxygen levels in the upper water column. The paleoceanographic significance of planktonic foraminifera with radially elongated chambers remains however unclear.

Journal of Micropalaeontology, 1993

ABSTRACT A detailed analysis was made of benthonic foraminiferal distribution patterns and morpho... more ABSTRACT A detailed analysis was made of benthonic foraminiferal distribution patterns and morphogroups in the late Albian "Amadeus Segment" of the Aptian-Albian organic-rich Scisti a Fucoidi Formation outcropping over a widespread area of the Umbria-Marche region, ...

Palaeogeography Palaeoclimatology Palaeoecology, 2002

The analysis of coiling direction preference in the benthic foraminifera Cibicidoides pseudoacutu... more The analysis of coiling direction preference in the benthic foraminifera Cibicidoides pseudoacutus (Nakkady) has been carried out across the Cretaceous^Tertiary boundary (K^T boundary) from four Tunisian sections representing a palaeobathymetric transect from a middle^outer neritic to lower upper bathyal depositional setting. Our study reveals that C. pseudoacutus developed a preference for sinistral coiling in a short time period during the lowermost Danian.

Palaeogeography Palaeoclimatology Palaeoecology, 2004

High-resolution micropalaeontological and chemostratigraphic records for the upper Cenomanian por... more 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 d 13 C curve showing a marked positive excursion (up to 4.7x ). The Bonarelli Level equivalent deposition is characterized by highly eutrophic conditions as testified by radiolarian proliferation. Black shale samples from the Calabianca -Guidaloca composite section contain very high TOC (up to 26%) and moderate to high amounts of CaCO 3 (on average 20%). Among the planktonic foraminifera, hedbergellids and globigerinelloids tolerated the environmental stress induced by the Oceanic Anoxic Event 2 (OAE2). The occurrence of some benthic foraminifera testifies to dysoxic rather than completely anoxic conditions at the sea floor during the deposition of some portions of the Bonarelli Level equivalent. Based on micropalaeontological results and geochemical proxies (d 13 C, D*, Rb, Ti, V, Ni, Ba, Si, Cr), the Bonarelli Level equivalent is interpreted as a highproductivity event driven by increasingly warm and humid climatic conditions promoting an accelerated hydrological cycle. We propose that periodically increased riverine influxes, triggered by enhanced humidity, resulted in a sluggish circulation mode and consequent anoxic/euxinic conditions favouring the preservation of organic matter at the sea-floor. Spectral analyses performed on selected geochemical signals reveal within the main high productivity event a strong orbital -0031-0182/$ -see front matter D (R. Neri).

Palaeogeography Palaeoclimatology Palaeoecology, 2003

The upper Albian Amadeus Segment, which falls within Oceanic Anoxic Event 1c, exhibits cyclical a... more 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 ...

Cretaceous Research, 1998

The Selli Level is a marker-bed in the Umbria-Marche Apennines that represents the regional sedim... more The Selli Level is a marker-bed in the Umbria-Marche Apennines that represents the regional sedimentary expression of the Lower Aptian Oceanic Anoxic Event 1a. This one to three-metre-thick interval shows a remarkable uniformity on a regional scale, with a green to grey marly lower part overlain by black shales. Bulk geochemical studies and an examination of palynofacies were carried out on three sections in order to characterise the distribution and nature of the organic matter in the Selli Level which has been poorly known hitherto. The organic content is medium (0.5 to 2.9% TOC) in the basal part and higher (4.5% on average, and up to 18% TOC) in the black shales. Pyrolysis and palynological data indicate that the organic matter is mainly of marine origin. The geochemical characteristics of the Selli Level are compared to other, more or less organic-rich marker-beds in the Cretaceous succession of the Umbria-Marche Apennines.

International Journal of Earth Sciences, 2007

The Faraoni Level is a short-lived oxygen-deficient event that took place during the latest Haute... more The Faraoni Level is a short-lived oxygen-deficient event that took place during the latest Hauterivian. In order to improve our understanding of the palaeoenvironmental conditions that occurred during this event, we have analysed the contents of several redox-sensitive trace elements (U, V, Mo, As, Co, Cd, Cu, Zn, Ni, Pb, Cr) from bulk limestone samples of late Hauterivian–early Barremian age from three reference sections. U, V, Mo and As show consistent and significant enrichments during the Faraoni event whereas the other redox-sensitive trace elements analysed here are not systematically enriched. In order to explain this discrepant behaviour, we propose that the Faraoni Level was deposited during a period of anoxic conditions near the sediment–water interface. The distinctive peaks in U, V, Mo and As contents are traceable throughout the three studied sections and represent a good correlation tool which helps to identify the Faraoni Level and its equivalents in the western Tethyan realm and outside of the Tethys. For example, a peak in U contents in upper Hauterivian sediments of the northwestern Pacific realm (ODP leg 185, site 1149) may well be an expression of the Faraoni event in this particular basin.

Terra Nova, 2000

The Eocene–Oligocene transition marks the passage from ‘greenhouse’ conditions to an ‘icehouse’ s... more The Eocene–Oligocene transition marks the passage from ‘greenhouse’ conditions to an ‘icehouse’ state, with progressive global cooling starting in the early middle Eocene. The late Eocene presents substantial evidence for extraterrestrial impacts whose effects on living organisms and climatic changes are still not completely clear. A high-resolution, microfloral and faunal investigation has been carried out in a 4-m-thick segment of the Massignano Global Stratotype Section and Point for the Eocene–Oligocene boundary. The studied interval includes a late Eocene (35.7 ± 0.4 Myr old) impactoclastic layer containing several cosmic signatures. The impact event recorded at Massignano had no abrupt, dramatic effects on marine biota in terms of extinction. However, significant quantitative changes in the calcareous plankton and dinoflagellate cyst assemblages occurred 60 kyr after the impact event. The observed pattern is intepreted as reflecting a long-term re-organization of water structure.

Geological Society of America Bulletin, 2007

We report a high-resolution paleomagnetic investigation constrained by new qualitative and semiqu... more We report a high-resolution paleomagnetic investigation constrained by new qualitative and semiquantitative analyses of planktic and benthic foraminifera, nannofossil assemblages, integrated with oxygen and carbon isotope measurements, for the middle Eocene Scaglia limestones of the Contessa Highway section, central Italy. Calcareous plankton assemblages enable recognition of several biostratigraphic events from planktic foraminiferal zone P11 to the lower part of zone P15 and from calcareous nannofossil zone NP15 to the upper part of zone NP17, which results in refi nement of the magnetobiostratigraphy of the Contessa Highway section. Correlation of the paleomagnetic polarity pattern with the geomagnetic polarity time scale provides a direct age interpretation for strata around the middle Eocene Scaglia limestones of the Contessa Highway section, from chrons C21n (47 Ma) through to subchron C18n.1n (38.5 Ma). Bulk carbon isotope values indicate a distinct carbon isotopic shift at 40 Ma that is interpreted to represent the fi rst evidence in the Northern Hemisphere of the middle Eocene climatic optimum, which has recently been observed as a stable isotope anomaly in multiple records from the Indian-Atlantic sector of the Southern Ocean. This demonstrates a global response of the carbon cycle to the proposed transient increased pCO 2 levels during the late middle Eocene and consequent global CO 2 -driven climate change.

Tectonics, 1994

During the Tertiary Period, the northeastern Apennines of Italy functioned as a quiet depositiona... more During the Tertiary Period, the northeastern Apennines of Italy functioned as a quiet depositional basin for fine-grained, volcanic ashfalls from distant explosive volcanism accompanying the Alpine/Apennine orogenesis. These ashes have been dated by several authors with different radioisotopic methods in the past decade (K/At, 4øAr/S9Ar, and Rb/Sr on biotite separates; 4øAr/39Ar single-crystal laser fusion on plagioclase and sanidine; and U/Pb on zircon) and provide the means for a precise, accurate age calibration of the Tertiary magnetostratigraphic and biostratigraphic timescales. However, the provenance of these tephras has remained uncertain. To resolve this problem, we have carried out detailed grain size analysis of the so-called "Livello Raffaello," a feldspar-bearing bentonite recognized in numerous outcrops throughout the region at the very base of the Aquitanian to Burdigalian Bisciaro formation. The Raffaello, stratigraphically located in the upper part of planktonic foraminiferal Zone N4 and calcareous nannofossil Zone NN1, upper Chron 6A-r (middle Aquitanian), yielded an isochron age of 21.2 _ 0.5 Ma (2(5) from 27 4øAr/39Ar dates by laser fusion on plagioclase. We measured the mean grain size M• of the >63-gm felsic fraction (i.e., feldspar and quartz) of the Raffaello in 11 representative outcrops in the region and compared the grain size against distance from two possible volcanic sources; the Venetian province (northern provenance) and the Sardinian province (western provenance). While the Venetian source shows no distinct trend of the MtI, distribution, the Sardinian plot exhibits a very clear linear grain size decrease with distance. After having tentatively established a Sardinian source (no other volcanoes of Aquitanian age are known west of the Apennine basin), we revised the M• distribution through palinspastic restoration, including the post-Aquitanian anticlockwise rotation of the Sardinian microplate and consequent orogenic shortening of the northeastern Apennine fold-andthrust belt. For this we have used the "thick-skinned" model of Lavecchia et al. (1984), which envisions a shortening for the northeastern Apennines of 3 to 30 km, and the "thin-skinned" model of (Bally et al., 1986), which assumes a variable shortening of 50 to 250 km. We have also modeled the distribution of the MtI, of felsic crystals for modern analogue stratospheric westerly winds blowing in this region from fall to spring at speeds of 10 to 30 m/s and altitudes ranging from 25 km to 40 Paper number 94TC00295. 027 8-7407/94/94TC-00295510.00

Earth and Planetary Science Letters, 2004

High-resolution studies (d 13 C, d 18 O, and elemental abundances) were done in rocks at and belo... more High-resolution studies (d 13 C, d 18 O, and elemental abundances) were done in rocks at and below the GSSP for the Eocene/ Oligocene (E/O) boundary at Massignano, Italy. In addition to an earlier known Ir anomaly at 5.61 m, which is possibly linked to the Popigai impact event, we confirm the presence of two additional Ir anomalies in the intervals from 6.00 to 6.40 m and from 10.00 to 10.50 m, with maximum values of 259 F 32 ppt at 6.17 m, and 149 F 24 ppt at 10.28 m, respectively. The lower Ir anomaly might be derived from the Chesapeake Bay impact event, whereas for the other one no impact event is known. Similar d 13 C and d 18 O trends related to the two Ir anomalies indicate that the Ir anomaly at 10.28 m might be also derived from an impact into a continental shelf, similar to the Chesapeake Bay impact event. d 18 O values decrease in the high Ir layers to À 1.16x and À 1.17x, respectively, which, together with the negative shifts in d 13 C in the Ir-rich levels, indicate a warm pulse superimposed on a general Late Eocene cooling trend that is characterized by d 18 O values ranging between À 0.6x and À 0.4x. The release of methane hydrate after an impact in a continental shelf or seafloor, or impacts of 12 C-rich comets during a 2.2-million-year-long comet shower, respectively, could produce these more negative carbon and oxygen excursions compared to the continuously decreasing trend over the whole Late Eocene Massignano section. D

Earth and Planetary Science Letters, 2008

The prelude to the second global oceanic-anoxic event of the Cretaceous (OAE 2), as recorded in t... more The prelude to the second global oceanic-anoxic event of the Cretaceous (OAE 2), as recorded in the classic sections of the Scaglia Bianca Formation in the Umbria-Marches region of Italy, is characterized by an oscillation between black to gray, organic-rich cherts and white pelagic limestones. Spectral analysis of these lithologic alternations reveals a robust set of cycles whose periods are remarkably similar to the orbital cycles calculated by Laskar et al. [Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., Levrard, B., 2004, A long term numerical solution for the insolation quantities of the Earth. Astronomy and Astrophysics, 428, 261-285.]. Bandpass filtering shows that the 140-80 kyr signal approximates the envelope of the 26-16 kyr signal, just as expected if these components represent responses to orbital eccentricity and precession. Matching the presumed eccentricity signal to the theoretical eccentricity of Laskar et al. yields an age for the base of the Bonarelli Level (onset of OAE 2 in Italy) of 94.21 Ma (93.72 Ma provides an alternative)

Earth and Planetary Science Letters, 2001

A nearly complete and undisturbed Miocene carbonate sequence is present in the easternmost part o... more A nearly complete and undisturbed Miocene carbonate sequence is present in the easternmost part of the Umbria-Marche basin, Italy, which is ideal for detailed and integrated stratigraphic investigations of the Miocene Epoch. In this study, we were trying to obtain evidence for ...

Marine Pollution Bulletin, 2009

In order to assess the response of benthic foraminifera to trace element pollution, a study of be... more In order to assess the response of benthic foraminifera to trace element pollution, a study of benthic foraminiferal assemblages was carried out into sediment samples collected from the Santa Gilla lagoon (Sardinia, Italy). The lagoon has been contaminated by industrial waste, mainly trace elements, as well as by agricultural and domestic effluent. The analysis of surficial sediment shows enrichment in trace elements, including Cr, Cu, Hg, Ni, Pb and Zn. Biotic and abiotic data, analyzed with multivariate techniques of statistical analysis, reveal a distinct separation of both the highly polluted and less polluted sampling sites. The innermost part of the lagoon, comprising the industrial complex at Macchiareddu, is exposed to a high load of trace elements which are probably enhanced by their accumulation in the finer sediment fraction. This area reveals lower diversity and higher percentages of abnormalities when compared to the outermost part of the lagoon.

Estuarine Coastal and Shelf Science, 2008

Benthic foraminifera are increasingly used as environmental bio-indicators of pollution in coasta... more Benthic foraminifera are increasingly used as environmental bio-indicators of pollution in coastal and marginal marine settings. Their community structure provides information on the general characteristics of the environment and some species are sensitive to specific environmental parameters. Among various criteria, the occurrence of test abnormalities may represent a useful bioindicator for monitoring environmental impacts in coastal regions. A study of living benthic foraminifera was carried out in 42 sediment samples collected from the central Adriatic coast of Italy. Benthic foraminiferal assemblages from this area are rich, well preserved, and dominated by Ammonia parkinsoniana, and subordinately by Ammonia tepida, Aubignyna perlucida, Eggerella scabra, and Nonionella turgida. Heavy metal concentrations have been analysed which indicate low polluted environmental conditions. Foraminiferal species and heavy metal concentrations were investigated both with bivariate (correlation matrix) and multivariate techniques of principal component analysis (PCA) and cluster analysis. Statistical analysis shows a possible control of these pollutants both on the taxonomic composition of the benthic foraminiferal assemblages and the development of test malformations. Increasing heavy metal contents lead to an increase in relative abundance of A. tepida A. perlucida, N. turgida and E. scabra, and a relative concurrent decrease in relative abundance of A. parkinsoniana and higher percentages of deformed specimens (FAI) and species (FMI). Our results confirm that A. parkinsoniana prefers clean to low polluted environments and show that it is a very sensitive and un-tolerant species to heavy metal pollution being deeply affected by heavy metal content even at low concentrations. Our findings also confirm the capacity of the A. tepida to tolerate increasing heavy metal concentrations, and highlights that A. perlucida, N. turgida and E. scabra can be considered as tolerant species at least in low polluted environments. Following this, A. parkinsoniana and A. tepida can be reciprocally considered good bioindicator of heavy metal pollution over the surveyed area. The development of test abnormalities with a variety of malformations is a noticeable feature over the study area where the living deformed assemblages are largely dominated by a few species. The low percentages of deformed specimens (Foraminiferal Abnormality Index up to 4.7, with 2 on average) match well with the low concentrations of heavy metals that lead to low polluted environmental conditions. This study confirms and supports the suitability of studying benthic foraminifera as a technique for the in situ continuous bio-monitoring of heavy metal pollution of coastal marine sediments.

Palaeogeography Palaeoclimatology Palaeoecology, 2005

... The Tethyan Bottaccione reference-section is 5.48 m thick (Fig. 2 and Fig. 3) and located in ... more ... The Tethyan Bottaccione reference-section is 5.48 m thick (Fig. 2 and Fig. 3) and located in the type-area of the BL, 1 km NE of the town of Gubbio, on the northern slope of the Bottaccione Gorge, along the road SS 298. The ...

Paleoceanography, 2006

A high-resolution pelagic bulk carbonate stable isotope record from a central Tethyan lower Creta... more A high-resolution pelagic bulk carbonate stable isotope record from a central Tethyan lower Cretaceous composite section is presented. Three well-exposed sedimentary sequences (Chiaserna Monte Acuto, Bosso, and Gorgo a Cerbara sections, central Italy) cropping out throughout the Maiolica Formation were correlated by a detailed magnetostratigraphy, lithostratigraphy, and calcareous plankton biostratigraphy in order to reconstruct a continuous composite record from the middle Berriasian to the lower Aptian. The integrated stratigraphy of the three sequences provided an accurate time framework for the new high-resolution C isotope curve which is presented in this study. The composite δ13C signal, recorded in the depth domain, was analyzed by combined Lomb-Scargle periodogram and weighted wavelet Z transform (WWZ) - weighted wavelet amplitudes (WWA) Foster wavelet spectral methodologies, both appropriate for unevenly sampled curves. These tools allowed us to unravel the main frequencies modulating the record and their hypothetical shift in depth, respectively. The long-term, ~400,000 and ~2,400,000 years, eccentricity cycles were consistently recorded throughout all the composite record. Once band-pass filtered in these two periodicity bands and compared to the lithologic pattern cycles identified throughout the composite sequence, the δ13C signal was used as a valuable proxy record for a reliable construction of an orbital tuning of the early Cretaceous. An estimated age for all the different stratigraphic events recognized throughout the composite record was reported. In particular, the reestimated ages of the paleomagnetic chrons, documented in the upper part of the record, show differences with those reported by Gradstein et al. (2004) up to ~2 m.y. The Valanginian carbon shift, present in the middle part of the composite sequence was estimated to be ~2.3 m.y. long. The good agreement between the estimated age of the base of this positive carbon isotope excursion (~136.34 m.y.) and the predominant volcanic phase associated to the Paranà-Etendeka large igneous province intrusion confirmed a possible cause-effect link between the two events.

Cretaceous Research, 1998

An integrated stratigraphic, palaeontological, and geochemical study has been carried out across ... more An integrated stratigraphic, palaeontological, and geochemical study has been carried out across the uppermost Hauterivian Faraoni Level of the Fiume Bosso section in the Umbria-Marche Apennines, Italy. This level represents a ®rst, prominent sign of the global changes that led to the widespread deposition of mid-Cretaceous organic-rich facies. Marked changes in the organic geochemical record and micro¯oral and micro-and macrofaunal assemblages occur within the interval. They are characteristic for short-term deposition in strongly dysoxic bottom conditions. Such changes probably re¯ect climatic variation which, in turn, induced variations in the palaeoceanographic regime.

Palaeogeography Palaeoclimatology Palaeoecology, 2006

Chamber elongation is a recurring morphological character in Cretaceous and Cenozoic planktonic f... more Chamber elongation is a recurring morphological character in Cretaceous and Cenozoic planktonic foraminiferal evolution suggesting that the clavate body-plan takes advantage through particular environmental conditions. Cretaceous planktonic foraminifera bearing radially elongated chambers become repeatedly a consistent component of assemblages in correspondence with the deposition of remarkable organic layers that record the effects of oceanic anoxic events (OAEs). Due to this apparent correspondence, chamber elongation has been recently interpreted as an adaptation to low oxygen levels in the upper water column. The paleoceanographic significance of planktonic foraminifera with radially elongated chambers remains however unclear.

Journal of Micropalaeontology, 1993

ABSTRACT A detailed analysis was made of benthonic foraminiferal distribution patterns and morpho... more ABSTRACT A detailed analysis was made of benthonic foraminiferal distribution patterns and morphogroups in the late Albian "Amadeus Segment" of the Aptian-Albian organic-rich Scisti a Fucoidi Formation outcropping over a widespread area of the Umbria-Marche region, ...

Palaeogeography Palaeoclimatology Palaeoecology, 2002

The analysis of coiling direction preference in the benthic foraminifera Cibicidoides pseudoacutu... more The analysis of coiling direction preference in the benthic foraminifera Cibicidoides pseudoacutus (Nakkady) has been carried out across the Cretaceous^Tertiary boundary (K^T boundary) from four Tunisian sections representing a palaeobathymetric transect from a middle^outer neritic to lower upper bathyal depositional setting. Our study reveals that C. pseudoacutus developed a preference for sinistral coiling in a short time period during the lowermost Danian.

Palaeogeography Palaeoclimatology Palaeoecology, 2004

High-resolution micropalaeontological and chemostratigraphic records for the upper Cenomanian por... more 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 d 13 C curve showing a marked positive excursion (up to 4.7x ). The Bonarelli Level equivalent deposition is characterized by highly eutrophic conditions as testified by radiolarian proliferation. Black shale samples from the Calabianca -Guidaloca composite section contain very high TOC (up to 26%) and moderate to high amounts of CaCO 3 (on average 20%). Among the planktonic foraminifera, hedbergellids and globigerinelloids tolerated the environmental stress induced by the Oceanic Anoxic Event 2 (OAE2). The occurrence of some benthic foraminifera testifies to dysoxic rather than completely anoxic conditions at the sea floor during the deposition of some portions of the Bonarelli Level equivalent. Based on micropalaeontological results and geochemical proxies (d 13 C, D*, Rb, Ti, V, Ni, Ba, Si, Cr), the Bonarelli Level equivalent is interpreted as a highproductivity event driven by increasingly warm and humid climatic conditions promoting an accelerated hydrological cycle. We propose that periodically increased riverine influxes, triggered by enhanced humidity, resulted in a sluggish circulation mode and consequent anoxic/euxinic conditions favouring the preservation of organic matter at the sea-floor. Spectral analyses performed on selected geochemical signals reveal within the main high productivity event a strong orbital -0031-0182/$ -see front matter D (R. Neri).

Palaeogeography Palaeoclimatology Palaeoecology, 2003

The upper Albian Amadeus Segment, which falls within Oceanic Anoxic Event 1c, exhibits cyclical a... more 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 ...

Cretaceous Research, 1998

The Selli Level is a marker-bed in the Umbria-Marche Apennines that represents the regional sedim... more The Selli Level is a marker-bed in the Umbria-Marche Apennines that represents the regional sedimentary expression of the Lower Aptian Oceanic Anoxic Event 1a. This one to three-metre-thick interval shows a remarkable uniformity on a regional scale, with a green to grey marly lower part overlain by black shales. Bulk geochemical studies and an examination of palynofacies were carried out on three sections in order to characterise the distribution and nature of the organic matter in the Selli Level which has been poorly known hitherto. The organic content is medium (0.5 to 2.9% TOC) in the basal part and higher (4.5% on average, and up to 18% TOC) in the black shales. Pyrolysis and palynological data indicate that the organic matter is mainly of marine origin. The geochemical characteristics of the Selli Level are compared to other, more or less organic-rich marker-beds in the Cretaceous succession of the Umbria-Marche Apennines.

International Journal of Earth Sciences, 2007

The Faraoni Level is a short-lived oxygen-deficient event that took place during the latest Haute... more The Faraoni Level is a short-lived oxygen-deficient event that took place during the latest Hauterivian. In order to improve our understanding of the palaeoenvironmental conditions that occurred during this event, we have analysed the contents of several redox-sensitive trace elements (U, V, Mo, As, Co, Cd, Cu, Zn, Ni, Pb, Cr) from bulk limestone samples of late Hauterivian–early Barremian age from three reference sections. U, V, Mo and As show consistent and significant enrichments during the Faraoni event whereas the other redox-sensitive trace elements analysed here are not systematically enriched. In order to explain this discrepant behaviour, we propose that the Faraoni Level was deposited during a period of anoxic conditions near the sediment–water interface. The distinctive peaks in U, V, Mo and As contents are traceable throughout the three studied sections and represent a good correlation tool which helps to identify the Faraoni Level and its equivalents in the western Tethyan realm and outside of the Tethys. For example, a peak in U contents in upper Hauterivian sediments of the northwestern Pacific realm (ODP leg 185, site 1149) may well be an expression of the Faraoni event in this particular basin.

Terra Nova, 2000

The Eocene–Oligocene transition marks the passage from ‘greenhouse’ conditions to an ‘icehouse’ s... more The Eocene–Oligocene transition marks the passage from ‘greenhouse’ conditions to an ‘icehouse’ state, with progressive global cooling starting in the early middle Eocene. The late Eocene presents substantial evidence for extraterrestrial impacts whose effects on living organisms and climatic changes are still not completely clear. A high-resolution, microfloral and faunal investigation has been carried out in a 4-m-thick segment of the Massignano Global Stratotype Section and Point for the Eocene–Oligocene boundary. The studied interval includes a late Eocene (35.7 ± 0.4 Myr old) impactoclastic layer containing several cosmic signatures. The impact event recorded at Massignano had no abrupt, dramatic effects on marine biota in terms of extinction. However, significant quantitative changes in the calcareous plankton and dinoflagellate cyst assemblages occurred 60 kyr after the impact event. The observed pattern is intepreted as reflecting a long-term re-organization of water structure.

Geological Society of America Bulletin, 2007

We report a high-resolution paleomagnetic investigation constrained by new qualitative and semiqu... more We report a high-resolution paleomagnetic investigation constrained by new qualitative and semiquantitative analyses of planktic and benthic foraminifera, nannofossil assemblages, integrated with oxygen and carbon isotope measurements, for the middle Eocene Scaglia limestones of the Contessa Highway section, central Italy. Calcareous plankton assemblages enable recognition of several biostratigraphic events from planktic foraminiferal zone P11 to the lower part of zone P15 and from calcareous nannofossil zone NP15 to the upper part of zone NP17, which results in refi nement of the magnetobiostratigraphy of the Contessa Highway section. Correlation of the paleomagnetic polarity pattern with the geomagnetic polarity time scale provides a direct age interpretation for strata around the middle Eocene Scaglia limestones of the Contessa Highway section, from chrons C21n (47 Ma) through to subchron C18n.1n (38.5 Ma). Bulk carbon isotope values indicate a distinct carbon isotopic shift at 40 Ma that is interpreted to represent the fi rst evidence in the Northern Hemisphere of the middle Eocene climatic optimum, which has recently been observed as a stable isotope anomaly in multiple records from the Indian-Atlantic sector of the Southern Ocean. This demonstrates a global response of the carbon cycle to the proposed transient increased pCO 2 levels during the late middle Eocene and consequent global CO 2 -driven climate change.