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,...
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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...
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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...
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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,...
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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...
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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...
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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...
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In: Variscan-Appalachian dynamics: The building of the late Paleozoic basement, 2002, p. 263-280
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...
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In: Tectonophysics, 2003, vol. 365, p. 7
The European Variscan and Alpine mountain chains are collisional orogens, and are built up of pre-Variscan "building blocks" which, in most cases, originated at the Gondwana margin. Such pre-Variscan elements were part of a pre-Ordovician archipelago-like continental ribbon in the former eastern prolongation of Avalonia, and their present-day distribution resulted from juxtaposition through...
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In: International Journal of Earth Sciences, 2002, vol. 91, no. 1, p. 35-52
Pre-Variscan basement elements of Central Europe appear in polymetamorphic domains juxtaposed through Variscan and/or Alpine tectonic events. Consequently, nomenclatures and zonations applied to Variscan and Alpine structures, respectively, cannot be valid for pre-Variscan structures. Comparing pre-Variscan relics hidden in the Variscan basement areas of Central Europe, the Alps included,...
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