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Université de Fribourg

Clypeina helvetica Morellet and Morellet, 1918, revisited. A Priabonian (Late Eocene) dasycladalean alga from the Diablerets Nappe of the Helvetic Alps, southwestern Switzerland

Schlagintweit, Felix ; Bover-Arnal, Telm ; Menkveld-Gfeller, Ursula ; Strasser, André

In: Facies, 2013, vol. 58, no. 1, p. 287-297

The dasycladale Clypeina helvetica was described and illustrated with six drawings by Morellet and Morellet (Bull Soc Géol Fr 4o ser 18:102–105, 1918) from the “Bartonian” of the Helvetic Zone of southwestern Switzerland. Since then, C. helvetica has not been reported again neither from Switzerland nor from any other locality. Abundant material sampled from the Priabonian Diablerets Member...

Université de Fribourg

Late Eocene transgressive sedimentation in the western Swiss Alps: Records of autochthonous and quasi-autochthonous biofacies on a karstic rocky shore

Bover-Arnal, Telm ; Jaramillo-Vogel, David ; Showani, Aso ; Strasser, André

In: Palaeogeography, Palaeoclimatology, Palaeoecology, 2011, vol. 312, no. 1-2, p. 24-39

Carbonate karst unconformities represent primary sequence-stratigraphic boundaries but, where sealed by marine sedimentary successions, also signify ancient rocky shores. During the Late Eocene (Priabonian), a shallow sea flooded the deeply karstified and brecciated Cretaceous carbonate bedrocks of the western Swiss Alps. Transgression resulted in the formation of a rocky archipelago of basement...

Université de Fribourg

Allozyme variation in diploid, polyploid and mixed-ploidy populations of the Pilosella alpicola group (Asteraceae): relation to morphology, origin of polyploids and breeding system

Šingliarová, Barbora ; Chrtek, Jindřich ; Plačková, Ivana ; Mráz, Patrik

In: Folia Geobotanica, 2011, p. -

The Pilosella alpicola group includes four species (P. alpicola s.str., P. ullepitschii, P. rhodopea and P. serbica) with allopatric distributions (Alps, Balkans, Carpathians) and contrasting cytotype patterns (diploid, diploid-polyploid and polyploid species). Whereas diploid taxa (P. ullepitschii and P. serbica) reproduce sexually, the mode of...

Université de Fribourg

The last erosional stage of the Molasse Basin and the Alps

Schlunegger, Fritz ; Mosar, Jon

In: International Journal of Earth Sciences, 2011, p. 1-16

We present a synoptic overview of the Miocene-present development of the northern Alpine foreland basin (Molasse Basin), with special attention to the pattern of surface erosion and sediment discharge in the Alps. Erosion of the Molasse Basin started at the same time that the rivers originating in the Central Alps were deflected toward the Bresse Graben, which formed part of the European Cenozoic...

Université de Fribourg

Evidence for oxic conditions during oceanic anoxic event 2 in the northern Tethyan pelagic realm

Westermann, S. ; Caron, Michèle ; Fiet, N. ; Fleitmann, D. ; Matera, V. ; Adatte, T. ; Föllmi, K. B.

In: Cretaceous Research, 2010, vol. 31, no. 5, p. 500-514

Upper Cenomanian pelagic sediments from the northern Alpine Helvetic fold-and-thrust belt (northern Tethyan margin) coeval with Oceanic Anoxic Event (OAE) 2 are characterized by the temporal persistence of micrite sedimentation and lack of organic carbon-rich layers. We studied an expanded section in the Chrummflueschlucht (east of Euthal, Switzerland), which encompasses the OAE 2 time interval....

Université de Fribourg

State of the art in rockfall – forest interactions

Dorren, Luuk ; Berger, Frédéric ; Jonsson, Martin J. ; Krautblatter, Michael ; Mölk, Michael ; Stoffel, Markus ; Wehrli, André

In: Schweizerische Zeitschrift fur Forstwesen, 2007, vol. 158, no. 6, p. 128-141

To effectively prevent rockfall related disasters below forested slopes, silvicultural, eco-engineering, civil engineering or mixed techniques can be used. To do this in a cost-efficient manner it is necessary to know the following: 1) where rockfall events occur and which magnitudes are likely, 2) to what extent the forest reduces the run-out distances, the jump heights and the energies of rocks...

Université de Fribourg

400 years of debris flow activity and triggering weather conditions: Ritigraben VS, Switzerland

Stoffel, Markus ; Lièvre, Igor ; Conus, Delphine ; Grichting, Michael A. ; Raetzo, Hugo ; Gärtner, Holger W. ; Monbaron, Michel

In: Arctic Antarctic and Alpine Research, 2005, vol. 37(3), p. 387-395

Three major rainfall events have caused considerable damage in the Valais region (Swiss Alps) since 1987. While important debris flows originating from periglacial environments were recorded during the August 1987 and September 1993 rainfall events, no debris flows occurred in October 2000. This paper aims at putting these large area events and the apparent increase in debris flow frequency into...