Université de Fribourg

The north-subducting Rheic Ocean during the Devonian: consequences for the Rhenohercynian ore sites

Raumer, Jürgen F. von ; Nesbor, Heinz-Dieter ; Stampfli, Gérard M.

In: International Journal of Earth Sciences, 2017, vol. 106, no. 7, p. 2279–2296

Base metal mining in the Rhenohercynian Zone has a long history. Middle-Upper Devonian to Lower Carboniferous sediment-hosted massive sulfide deposits (SHMS), volcanic-hosted massive sulfide deposits (VHMS) and Lahn-Dill-type iron, and base metal ores occur at several sites in the Rhenohercynian Zone that stretches from the South Portuguese Zone, through the Lizard area, the Rhenish Massif...

Université de Fribourg

Ediacaran to Cambrian oceanic rocks of the Gondwana margin and their tectonic interpretation

Raumer, Jürgen F. von ; Stampfli, Gérard M. ; Arenas, Ricardo ; Martínez, Sonia Sánchez

In: International Journal of Earth Sciences, 2015, p. 1–15

In tectonic maps of Variscan Europe, allochthonous pieces of Cadomian basement clearly stand out with their predominant metabasic to ultrabasic elements, the so-called exotic terranes with ophiolites. Most of these domains are observed in basements of the Central Iberian Allochthone, the South Armorican domain, the nappe structures of the French Massif Central, the Saxothuringian Zone and the...

Université de Fribourg

Durbachites–Vaugnerites – a geodynamic marker in the central European Variscan orogen

Raumer, Jürgen F. von ; Finger, Fritz ; Veselá, Petra ; Stampfli, Gérard M.

In: Terra Nova, 2014, vol. 26, no. 2, p. 85–95

Durbachites–Vaugnerites are K–Mg-rich magmatic rocks derived from an enriched mantle source. Observed throughout the European Variscan basement, their present-day geographical distribution does not reveal any obvious plate-tectonic context. Published geochronological data show that most durbachites–vaugnerites formed around 335–340 Ma. Plotted in a Visean plate-tectonic reconstruction,...

Université de Fribourg

Pre-Mesozoic Alpine basements—Their place in the European Paleozoic framework

Raumer, Jürgen F. von ; Bussy, François ; Schaltegger, Urs ; Schulz, Bernhard ; Stampfli, Gérard M.

In: Bulletin of the Geological Society of America, 2013, vol. 125, no. 1-2, p. 89-108

Prior to their Alpine overprinting, most of the pre-Mesozoic basement areas in Alpine orogenic structures shared a complex evolution, starting with Neoproterozoic sediments that are thought to have received detrital input from both West and East Gondwanan cratonic sources. A subsequent Neoproterozoic–Cambrian active margin setting at the Gondwana margin was followed by a Cambrian–Ordovician...

Université de Fribourg

Discovery of Ordovician–Silurian metamorphic monazite in garnet metapelites of the Alpine External Aiguilles Rouges Massif

Schulz, Bernhard ; Raumer, Jürgen F. von

In: Swiss Journal of Geosciences, 2011, vol. 104, no. 1, p. 67-79

The pre-Mesozoic, mainly Variscan metamorphic basement of the Col de Bérard area (Aiguilles Rouges Massif, External domain) consists of paragneisses and micaschists together with various orthogneisses and metabasites. Monazite in metapelites was analysed by the electron microprobe (EMPA-CHIME) age dating method. The monazites in garnet micaschists are dominantly of Variscan age (330–300 Ma)....

Université de Fribourg

Discovery of Ordovician–Silurian metamorphic monazite in garnet metapelites of the Alpine External Aiguilles Rouges Massif

Schulz, Bernhard ; Raumer, Jürgen F. von

In: Swiss Journal of Geosciences, 2011, vol. 104, no. 1, p. 67-79

The pre-Mesozoic, mainly Variscan metamorphic basement of the Col de Bérard area (Aiguilles Rouges Massif, External domain) consists of paragneisses and micaschists together with various orthogneisses and metabasites. Monazite in metapelites was analysed by the electron microprobe (EMPA-CHIME) age dating method. The monazites in garnet micaschists are dominantly of Variscan age (330–300 Ma)....

Université de Fribourg

The Variscan evolution in the External massifs of the Alps and place in their Variscan framework

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

In: Comptes Rendus Geosciences, 2009, vol. 341, no. 2-3, p. 239-252

In the general discussion on the Variscan evolution of central Europe the pre-Mesozoic basement of the Alps is, in many cases, only included with hesitation. Relatively well-preserved from Alpine metamorphism, the Alpine External massifs can serve as an excellent example of evolution of the Variscan basement, including the earliest Gondwana-derived microcontinents with Cadomian relics. Testifying...

Université de Fribourg

The birth of the Rheic Ocean — Early Palaeozoic subsidence patterns and subsequent tectonic plate scenarios

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

In: Tectonophysics, 2008, vol. 461, no. 1-4.1, p. 9-20

New plate-tectonic reconstructions of the Gondwana margin suggest that the location of Gondwana-derived terranes should not only be guided by the models, but should also consider the possible detrital input from some Asian blocks (Hunia), supposed to have been located along the Cambrian Gondwana margin, and accreted in the Silurian to the North-Chinese block. Consequently, the Gondwana margin has...

Université de Fribourg

Paleozoic evolution of pre-Variscan terranes: From Gondwana to the Variscan collision

Stampfli, Gérard M. ; Raumer, Jürgen F. von ; Borel, Gilles D.

In: Geological Society of America Special Paper, 2002, vol. 364, p. 263

The well-known Variscan basement areas of Europe contain relic terranes with a pre-Variscan evolution testifying to their peri-Gondwanan origin (e.g., relics of Neoproterozoic volcanic arcs, and subsequent stages of accretionary wedges, backarc rifting, and spreading). The evolution of these terranes was guided by the diachronous subduction of the proto-Tethys oceanic ridge under different...