Perfeziona i miei risultati

Document type


Collection spécifique


  • Inglese (53) disattivare il filtro
Université de Fribourg

The genus Amphistegina (benthic foraminifera): distribution along the southern Tunisian coast

Kateb, Akram El ; Stalder, Claudio ; Stainbank, Stephanie ; Fentimen, Robin ; Spezzaferri, Silvia

In: BioInvasions Records, 2018, vol. 7, no. 4, p. 391–398

The benthic foraminiferal genus Amphistegina is currently expanding its range in the Mediterranean Sea after being introduced through the Suez Canal from the Red Sea. Over the previous decade, Amphistegina spp. has colonized the eastern part of the Mediterranean Sea including the Egyptian and Libyan coasts, but the present southern limit in the Mediterranean Sea is along the southern Tunisian...

Université de Fribourg

Revision of the planktonic foraminiferal biostratigraphy of the Voirons Flysch (Chablais Prealps, Haute-Savoie, France)

Ragusa, Jérémy ; Ospina-Ostios, Lina Maria ; Spezzaferri, Silvia ; Kindler, Pascal

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 461–473

The ages obtained from planktonic foraminiferal assemblages retrieved from two exposures in the Gurnigel Flysch and from the re-examination of similar material gathered by previous researchers from the Voirons Flysch reveal only minor discrepancies with previous studies based on nannofossil biostratigraphy. In contrast, major divergences between this work and previous studies on the Voirons...

Université de Fribourg

The Planktonic foraminifera Globigerinoides eoconglobatus n. sp. in a glacial–interglacial context: IODP359 Sites U1467 and U1468

Stainbank, Stephanie ; Spezzaferri, Silvia ; Kroon, Dick ; Leau, Erica S. de ; Rüggeberg, Andres

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 511–522

Here we define a new morphospecies of planktonic foraminifera Globigerinoides eoconglobatus n. sp., identified from International Ocean Discovery Program (IODP) expedition 359 samples from drift deposits of the Maldives, Inner Sea. Through biostratigraphic analysis, we infer it may be the direct ancestor of Globigerinoides conglobatus evolving from Globigerinoides obliquus in the Late Miocene...

Université de Fribourg

New insights on coral mound development from groundtruthed high-resolution ROV-mounted multibeam imaging

Lim, Aaron ; Huvenne, Veerle A.I. ; Vertino, Agostina ; Spezzaferri, Silvia ; Wheeler, Andrew J.

In: Marine Geology, 2018, vol. 403, p. 225–237

Currents play a vital role in sustaining and developing deep water benthic habitats by mobilising food and nutrients to otherwise relatively barren parts of the seabed. Where sediment supply is significant, it can have a major influence on the development and morphology of these habitats. This study examines a segment of the Belgica Mound Province, NE Atlantic to better constrain the...

Université de Fribourg

Large-scale paleoceanographic variations in the western Mediterranean Sea during the last 34,000 years: From enhanced cold-water coral growth to declining mounds

Stalder, Claudio ; El Kateb, Akram ; Vertino, Agostina ; Rüggeberg, Andres ; Camozzi, Osvaldo ; Pirkenseer, Claudius M. ; Spangenberg, Jorge E. ; Hajdas, Irka ; Rooij, David Van ; Spezzaferri, Silvia

In: Marine Micropaleontology, 2018, vol. 143, p. 46–62

Quantitative and qualitative analyses of cold-water coral (CWC) fragments from two sediment cores obtained from the Melilla Mounds Field (MMF) in the Alboran Sea, western Mediterranean Sea, reveal an alternation of periods dominated by distinct CWC species. The lower parts of the cores are dominated by the CWC species Lophelia pertusa, which is successively replaced in the upper parts by the...

Université de Fribourg

Late glacial and Holocene Ostracoda from the Melilla cold-water coral mound field

Pirkenseer, Claudius M. ; Spezzaferri, Silvia ; Stalder, Claudio

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 549–560

The ostracod assemblages from sediment core TTR17-401G recovered from the Melilla cold-water coral mound field in the eastern Alboran Sea spanning the last 13 ka are analysed quantitatively, taxonomically and palaeoecologically. The core can be subdivided in three distinct assemblages linked to environmental shifts during the Younger Dryas and the Bølling–Allerød interstadial. A total of...

Université de Fribourg

High-resolution monitoring of water temperature and oxygen concentration in Lake Murten (Switzerland)

Kateb, Akram El ; Rüggeberg, Andres ; Stalder, Claudio ; Neururer, Christoph ; Spezzaferri, Silvia

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 501–510

Lake Murten is located in the Lake District in western Switzerland and so far, it has been poorly investigated. The Environmental Service of Fribourg (SEn) has monitored this lake once a month for several years by water profiles (water temperature, pH, dissolved oxygen, conductivity) at its deepest part. The SEn identified the stratification of water masses as one of the main causes for...

Université de Fribourg

Distribution of benthic foraminiferal assemblages in the transitional environment of the Djerba lagoon (Tunisia)

Kateb, Akram El ; Stalder, Claudio ; Neururer, Christoph ; Fentimen, Robin ; Spangenberg, Jorge E. ; Spezzaferri, Silvia

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 589–606

The eastern edge of the Djerba Island represents an important tourist pole. However, studies describing the environmental processes affecting this Island are scarce. Although never studied before, the peculiar Djerba lagoon is well known by the local population and by tourists. In July 2014, surface sediment and seawater samples were collected in this lagoon to measure grain size, organic...

Université de Fribourg

Biostratigraphy of large benthic foraminifera from Hole U1468A (Maldives): a CT-scan taxonomic approach

Coletti, Giovanni ; Stainbank, Stephanie ; Fabbrini, Alessio ; Spezzaferri, Silvia ; Foubert, Anneleen ; Kroon, Dick ; Betzler, Christian

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 523–536

Large benthic foraminifera are important components of tropical shallow water carbonates. Their structure, developed to host algal symbionts, can be extremely elaborate and presents stratigraphically-significant evolutionary patterns. Therefore their distribution is important in biostratigraphy, especially in the Indo-Pacific area. To provide a reliable age model for two intervals of IODP...

Université de Fribourg

Benthic foraminifera in a deep-sea high-energy environment: the Moira Mounds (Porcupine Seabight, SW of Ireland)

Fentimen, Robin ; Rüggeberg, Andres ; Lim, Aaron ; El Kateb, Akram ; Foubert, Anneleen ; Wheeler, Andrew J. ; Spezzaferri, Silvia

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 561–572

Cold-water coral ecosystems represent unique and exceptionally diverse environments in the deep-sea. They are well developed along the Irish margin, varying broadly in shape and size. The Moira Mounds, numerous small-sized mounds, are nestled in the Belgica Mound Province (Porcupine Seabight, North-East Atlantic). The investigation of living (Rose Bengal stained) and dead benthic...