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Université de Fribourg

Ollo de Sapo Cambro-Ordovician volcanics from the Central Iberian basement—A multiphase evolution

Raumer, Jürgen F. von ; Stampfli, Gérard M.

In: Terra Nova, 2018, vol. 30, no. 5, p. 350–358

The Cambro-Ordovician rhyodacitic to dacitic volcanics from the Central Iberian basement, currently known as Ollo de Sapo (toads eye), have been reported as a specific group of felsic porphyritic rocks with blue quartz and large phenocrysts of K- feldspar, in a partly vitreous or fine-grained matrix. Interpreted to form Cambro- Ordovician volcanic domes, they are accompanied by tuffs,...

Université de Fribourg

Little ice age glacier history of the central and western alps from pictorial documents

Zumbühl, Heinz J. ; Nussbaumer, Samuel U.

In: Cuadernos de Investigación Geográfica, 2018, vol. 44, no. 1, p. 115–136

The Lower Grindelwald Glacier (Bernese Oberland, Switzerland) consists of two parts, the Ischmeer in the east (disconnected) and the Bernese Fiescher Glacier in the west. During the Little Ice Age (LIA), the glacier terminated either in the area of the “Schopffelsen” (landmark rock terraces) or advanced at least six times (ten times if we include early findings) even further down into the...

Université de Fribourg

Non-invasive Raman identification of crystalline and glassy phases in a 1781 Sèvres Royal Factory soft paste porcelain plate

Colomban, Philippe ; Maggetti, Marino ; Albis, Antoine d’

In: Journal of the European Ceramic Society, 2018, vol. 38, no. 15, p. 5228–5233

A Raman study of a Sèvres soft paste (frit) porcelain plate allowed the identification of both the crystalline and amorphous phases. Cristobalite and pseudowollastonite gave main Raman signatures in the body where also tridymite, amorphous alkali silicate glass and lead arsenate apatite were detected. Na0.4K0.1Ca0.5Pb4(AsO4)3 lacunar apatite is identified as opacifier in blue and green...

Université de Fribourg

Archaeometric analyses of european 18th–20th century white earthenware—a review

Maggetti, Marino

In: Minerals, 2018, vol. 8, no. 7, p. 269

This study provides an overview of the few archaeometric analyses of European white earthenwares from England, France, Italy, Slovenia, and Switzerland. White earthenwares were an extremely successful mass-product between ca. 1750 and 1900. They became “the porcelain of the poor man” and replaced the older traditional pottery such as faïence. The invention of this new ceramic type took...

Université de Fribourg

A snow density dataset for improving surface boundary conditions in greenland ice sheet firn modeling

Fausto, Robert S. ; Box, Jason E. ; Vandecrux, Baptiste ; As, Dirk van ; Steffen, Konrad ; MacFerrin, Michael J. ; Machguth, Horst ; Colgan, William ; Koenig, Lora S. ; McGrath, Daniel ; Charalampidis, Charalampos ; Braithwaite, Roger J.

In: Frontiers in Earth Science, 2018, vol. 6, p. -

The surface snow density of glaciers and ice sheets is of fundamental importance in converting volume to mass in both altimetry and surface mass balance studies, yet it is often poorly constrained. Site-specific surface snow densities are typically derived from empirical relations based on temperature and wind speed. These parameterizations commonly calculate the average density of the top...

Université de Fribourg

Numerical reconstructions of the flow and basal conditions of the Rhine glacier, European Central Alps, at the Last Glacial Maximum

Cohen, Denis ; Gillet-Chaulet, Fabien ; Haeberli, Wilfried ; Machguth, Horst ; Fischer, Urs H.

In: The Cryosphere, 2018, vol. 12, no. 8, p. 2515–2544

At the Last Glacial Maximum (LGM), the Rhine glacier in the Swiss Alps covered an area of about 16000km2. As part of an integrative study about the safety of repositories for radioactive waste under ice age conditions in Switzerland, we modeled the Rhine glacier using a thermodynamically coupled three-dimensional, transient Stokes flow and heat transport model down to a horizontal resolution...

Université de Fribourg

Elevation changes of the Holm Land Ice Cap, northeast Greenland, from 1978 to 2012–2015, derived from high-resolution digital elevation models

Albedyll, Luisa von ; Machguth, Horst ; Nussbaumer, Samuel U. ; Zemp, Michael

In: Arctic, Antarctic, and Alpine Research, 2018, vol. 50, no. 1, p. e1523638

Greenland’s peripheral glaciers and ice caps are key indicators of climate change in the Arctic, but quantitative observational data of their recent evolution are sparse. Three recently released high-resolution digital elevation models (DEMs)—AeroDEM (based on images from 1978 to 1987), ArcticDEM (2012–2015), and TanDEM-X (2010–2014)—provide the possibility to calculate elevation...

Université de Fribourg

Near-surface ventilation as a key for modeling the thermal regime of coarse blocky rock glaciers

Pruessner, Luisa ; Phillips, Marcia ; Farinotti, Daniel ; Hoelzle, Martin ; Lehning, Michael

In: Permafrost and Periglacial Processes, 2018, vol. 29, no. 3, p. 152–163

In a changing climate, ice‐rich permafrost features such as rock glaciers will experience drastic changes. Modeling the heat transport through the blocky surface layer with its large interstitial pore spaces poses some challenges as various modes of non‐conductive heat transport—advective forms in particular—can occur. Here, we show that the 1D physics‐based model SNOWPACK can be...

Université de Fribourg

Multi-proxy facies analysis of the Opalinus Clay and depositional implications (Mont Terri rock laboratory, Switzerland)

Lauper, Bruno ; Jaeggi, David ; Deplazes, Gaudenz ; Foubert, Anneleen

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 383–398

Located in NW Switzerland, the Mont Terri rock laboratory is a research facility primarily investigating the Opalinus Clay as potential host rock for deep geological disposal of radioactive waste. In the Mont Terri area, this Jurassic shale formation is characterized by three distinctive lithofacies: a shaly facies, a carbonate-rich sandy facies and a sandy facies. However, the lithological...