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

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

Impact of industrial phosphate waste discharge on the marine environment in the Gulf of Gabes (Tunisia)

Kateb, Akram El ; Stalder, Claudio ; Rüggeberg, Andres ; Neururer, Christoph ; Spangenberg, Jorge E. ; Spezzaferri, Silvia

In: PLOS ONE, 2018, vol. 13, no. 5, p. e0197731

The marine environment in the Gulf of Gabes (southern Tunisia) is severely impacted by phosphate industries. Nowadays, three localities, Sfax, Skhira and Gabes produce phosphoric acid along the coasts of this Gulf and generate a large amount of phosphogypsum as a waste product. The Gabes phosphate industry is the major cause of pollution in the Gulf because most of the waste is directly...

Université de Fribourg

Microfossils, a key to unravel cold-water carbonate mound evolution through time: Evidence from the eastern alboran sea

Stalder, Claudio ; Vertino, Agostina ; Rosso, Antonietta ; Rüggeberg, Andres ; Pirkenseer, Claudius ; Spangenberg, Jorge E. ; Spezzaferri, Silvia ; Camozzi, Osvaldo ; Rappo, Sacha ; Hajdas, Irka

In: PLoS ONE, 2015, vol. 10, no. 10, p. e0140223

Cold-water coral (CWC) ecosystems occur worldwide and play a major role in the ocean's carbonate budget and atmospheric CO2 balance since the Danian (~65 m.y. ago). However their temporal and spatial evolution against climatic and oceanographic variability is still unclear. For the first time, we combine the main macrofaunal components of a sediment core from a CWC mound of the Melilla Mounds...

Université de Fribourg

Sulfur isotope analysis of cinnabar from Roman wall paintings by elemental analysis/isotope ratio mass spectrometry – tracking the origin of archaeological red pigments and their authenticity

Spangenberg, Jorge E. ; Lavrič, Jošt V. ; Meisser, Nicolas ; Serneels, Vincent

In: Rapid Communications in Mass Spectrometry, 2010, vol. 24, no. 19, p. 2812-2816

The most valuable pigment of the Roman wall paintings was the red color obtained from powdered cinnabar (Minium Cinnabaris pigment), the red mercury sulfide (HgS), which was brought from mercury (Hg) deposits in the Roman Empire. To address the question of whether sulfur isotope signatures can serve as a rapid method to establish the provenance of the red pigment in Roman frescoes, we...