Université de Fribourg

Constraining the formation of authigenic carbonates in a seepage-affected cold-water coral mound by lipid biomarkers

Feenstra, Eline Juliette ; Birgel, Daniel ; Heindel, Katrin ; Wehrmann, Laura M. ; Jaramillo‐Vogel, David ; Grobéty, Bernard ; Frank, Norbert ; Hancock, Leanne G. ; Van Rooij, David ; Peckmann, Jörn ; Foubert, Anneleen

In: Geobiology, 2020, vol. 18, no. 2, p. 185–206

Cold‐water coral (CWC) mounds are build‐ups comprised of coral‐dominated intervals alternating with a mixed carbonate‐siliciclastic matrix. At some locations, CWC mounds are influenced by methane seepage, but the impact of methane on CWC mounds is poorly understood. To constrain the potential impact of methane on CWC mound growth, lipid biomarker investigations were combined with...

Université de Fribourg

Eifel maars: Quantitative shape characterization of juvenile ash particles (Eifel Volcanic Field, Germany)

Rausch, Juanita ; Grobéty, Bernard ; Vonlanthen, Pierre

In: Journal of Volcanology and Geothermal Research, 2015, vol. 291, p. 86–100

The Eifel region in western central Germany is the type locality for maar volcanism, which is classically interpreted to be the result of explosive eruptions due to shallow interaction between magma and external water (i.e. phreatomagmatic eruptions). Sedimentary structures, deposit features and particle morphology found in many maar deposits of the West Eifel Volcanic Field (WEVF), in contrast...

Université de Fribourg

Geomorphic response to the lateglacial–holocene transition in high alpine regions (Sanetsch pass, Swiss alps)

Serra, Elena ; Valla, Pierre G. ; Gribenski, Natacha ; Guedes Magrani, Fabio ; Carcaillet, Julien ; Delaloye, Reynald ; Grobéty, Bernard ; Braillard, Luc

In: Boreas, 2020, p. bor.12480

Several palaeoclimatic archives have documented the pronounced climatic and environmental change associated with the Lateglacial–Holocene transition in the European Alps. However, the geomorphic response to this major environmental transition has only been punctually investigated. In this study, we propose a detailed reconstruction of post‐Last Glacial Maximum palaeoenvironmental...

Université de Fribourg

High-resolution 3D analyses of the shape and internal constituents of small volcanic ash particles: The contribution of SEM micro-computed tomography (SEM micro-CT)

Vonlanthen, Pierre ; Rausch, Juanita ; Ketcham, Richard A. ; Putlitz, Benita ; Baumgartner, Lukas P. ; Grobéty, Bernard

In: Journal of Volcanology and Geothermal Research, 2015, vol. 293, p. 1–12

The morphology of small volcanic ash particles is fundamental to our understanding of magma fragmentation, and in transport modeling of volcanic plumes and clouds. Until recently, the analysis of 3D features in small objects (< 250 μm) was either restricted to extrapolations from 2D approaches, partial stereo-imaging, or CT methods having limited spatial resolution and/or accessibility. In...

Université de Fribourg

The Malpaisillo Formation: A sequence of explosive eruptions in the mid to late Pleistocene (Nicaragua, Central America)

Stoppa, Line ; Kutterolf, Steffen ; Rausch, Juanita ; Grobéty, Bernard ; Pettke, Thomas ; Wang, Kuo-Lung ; Hemming, Sidney

In: Journal of Volcanology and Geothermal Research, 2018, vol. 359, p. 47–67

The subduction-related volcanic front in Nicaragua consists of the Tertiary “Coyol” member in the eastern highlands and the Quaternary to recent volcanic arc within the Nicaraguan depression. Although the Holocene to recent explosive volcanism has been studied extensively no detailed work has been done on the products of explosive volcanism from Quaternary volcanic complexes comprising...

Université de Fribourg

Pleistocene sea-floor fibrous crusts and spherulites in the Danakil Depression (Afar, Ethiopia)

Jaramillo‐Vogel, David ; Foubert, Anneleen ; Braga, Juan Carlos ; Schaegis, Jean‐Charles ; Atnafu, Balemwal ; Grobéty, Bernard ; Kidane, Tesfaye

In: Sedimentology, 2019, vol. 66, no. 2, p. 480–512

Pleistocene fibrous aragonite fabrics, including crusts and spherules, occur in the Danakil Depression (Afar, Ethiopia) following the deposition of two distinctive Middle and Late Pleistocene coralgal reef units and pre‐dating the precipitation of evaporites. Crusts on top of the oldest reef unit (Marine Isotope Stage 7) cover and fill cavities within a red algal framework. The younger...

Université de Fribourg

Quantification of mass transfers and mineralogical transformations in a thrust fault (Monte Perdido thrust unit, southern Pyrenees, Spain)

Trincal, Vincent ; Charpentier, Delphine ; Buatier, Martine D. ; Grobéty, Bernard ; Lacroix, Brice ; Labaume, Pierre ; Sizun, Jean-Pierre

In: Marine and Petroleum Geology, 2014, vol. 55, p. 160-175

In fold-and-thrust belts, shortening is mainly accommodated by thrust faults which are preferential zones for recrystallisation and mass transfer. This study focuses on a detachment fault related to the emplacement of the Monte Perdido thrust unit in the southern Pyrenees. The studied fault zone consists of a 10 m thick intensively foliated phyllonite developed within the Millaris marls, of...