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Université de Fribourg

Geochemical fingerprinting of key lithologies and depositional processes across the upper boundary of the Opalinus Clay (Aalenian, Middle Jurassic, northern Switzerland)

Lauper, Bruno ; Deplazes, Gaudenz ; Vogel, Hendrik ; Jaeggi, David ; Wohlwend, Stephan ; Ariztegui, Daniel ; Foubert, Anneleen

In: The Depositional Record, 2021, vol. 7, no. 1, p. 25-51

The Opalinus Clay is an argillaceous to silty mudstone formation, notable in Switzerland as the selected host rock for deep geological disposal of radioactive waste. Its upper bounding unit (Passwang Formation and eastern equivalents) is composed of successions of mudstone, sandy bioclastic marl and limestone separated by ooidal ironstone beds. The lithostratigraphic transition is diachronous...

Université de Fribourg

Recent glacier and lake changes in High Mountain Asia and their relation to precipitation changes

Treichler, Désirée ; Kääb, Andreas ; Salzmann, Nadine ; Xu, Chong-Yu

In: The Cryosphere, 2019, vol. 13, no. 11, p. 2977–3005

We present an updated, spatially resolved estimate of 2003–2008 glacier surface elevation changes for the entire region of High Mountain Asia (HMA) from ICESat laser altimetry data. The results reveal a diverse pattern that is caused by spatially greatly varying glacier sensitivity, in particular to precipitation availability and changes. We introduce a spatially resolved zonation where...

Université de Fribourg

Integrated bio- and cyclostratigraphy of Middle Triassic (Anisian) ramp deposits, NW Bulgaria

Ajdanlijsky, George ; Strasser, André ; Götz, Annette E.

In: Geologica Carpathica, 2019, vol. 70, no. 4, p. 325–354

A cyclostratigraphic interpretation of peritidal to shallow-marine ramp deposits of the early Middle Triassic (Anisian) Opletnya Member exposed in outcrops along the Iskar River gorge, NW Bulgaria, is presented. Based on facies trends and bounding surfaces, depositional sequences of several orders can be identified. New biostratigraphic data provide a time frame of the studied succession with...

Université de Fribourg

Remote sensing of cropping practice in Northern Italy using time-series from Sentinel-2

Ottosen, Thor-Bjørn ; Lommen, Suzanne T.E. ; Skjøth, Carsten Ambelas

In: Computers and Electronics in Agriculture, 2019, vol. 157, p. 232–238

Maps of cropping practice, including the level of weed infestation, are useful planning tools e.g. for the assessment of the environmental impact of the crops, and Northern Italy is an important example due to the large and diverse agricultural production and the high weed infestation. Sentinel-2A is a new satellite with a high spatial and temporal resolution which potentially allows the...

Université de Fribourg

Estimating economic benefits of biological control of Ambrosia artemisiifolia by Ophraella communa in southeastern France

Mouttet, Raphaelle ; Augustinus, Benno ; Bonini, Maira ; Chauvel, Bruno ; Desneux, Nicolas ; Gachet, Emmanuel ; Le Bourgeois, Thomas ; Müller-Schärer, Heinz ; Thibaudon, Michel ; Schaffner, Urs

In: Basic and Applied Ecology, 2018, vol. 33, p. 14–24

The North American common ragweed, Ambrosia artemisiifolia, which produces highly allergenic pollen, is invasive in different parts of the world, including Europe. In 2013, common ragweed in northern Italy was found attacked by another accidentally introduced species, the North American leaf beetle Ophraella communa, which is used for biological control of common ragweed in China. Since the...

Université de Fribourg

Age and synchronicity of planktonic foraminiferal bioevents across the Cenomanian – Turonian boundary interval (Late Cretaceous)

Falzoni, Francesca ; Petrizzo, Maria Rose ; Caron, Michèle ; Leckie, R. Mark ; Elderbak, Khalifa

In: Newsletters on Stratigraphy, 2018, vol. 51, no. 3, p. 343–380

The upper Cenomanian – lower Turonian is a key-stratigraphic interval, as it encompasses the Late Cretaceous supergreenhouse and a major perturbation of the global carbon cycle (i. e., Oceanic Anoxic Event 2) as evidenced by a global positive carbon isotope excursion and by the nearly world-wide deposition of organic-rich marine facies. A turnover in planktonic foraminiferal assemblages and...