Results 131 to 140 of about 273 (174)
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The age of the paroxysmal Variscan orogeny in England
Geological Society, London, Special Publications, 1964Summary Potassium–argon age-determinations on 10 basic igneous rocks from the English Midlands indicate two distinct episodes of magmatic intrusion. Geological evidence and Permo-Carboniferous isotopic age data from Britain confirm the well-known close relationship between magmatism and earth-movements.
Frank Joseph Fitch, John Alfred Miller
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Magnetic fabrics in Portuguese Variscan granites: structural markers of the Variscan orogeny
2020<p>This work focuses on the magnetic fabric of 20 variscan granitic massifs from northern and central Portugal and considers the Anisotropy of Magnetic Susceptibility (AMS) results obtained in about 750 sampling sites. In the northern and central Portugal, three main ductile deformation phases were recognized and described: D&
Helena Sant Ovaia +3 more
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Elements
Numerical and analogue modeling provides insights into dynamic processes shaping convergent plate boundaries. In the case of the Variscan orogeny, efforts to explain observations using physics-based models started in the late 1990s with 2D numerical simulations and have evolved towards advanced 2D petrological–thermomechanical numerical simulations and
Taras Gerya, Petra Maierová
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Numerical and analogue modeling provides insights into dynamic processes shaping convergent plate boundaries. In the case of the Variscan orogeny, efforts to explain observations using physics-based models started in the late 1990s with 2D numerical simulations and have evolved towards advanced 2D petrological–thermomechanical numerical simulations and
Taras Gerya, Petra Maierová
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Variscan orogeny: a three ocean problem
ElementsVariscan orogenic evolution was dominated by closure of the Rheic Ocean and its two successors, the Rhenohercynian and Paleotethys oceans. The Rheic subduction started in late Silurian – early Devonian at the margin of Laurussia but also along two Gondwana derived continental ribbons. Rapid mid-Devonian roll-back of peri-Laurentian subduction
Karel Schulmann +2 more
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Detrital zircons and the interpretation of palaeogeography, with the Variscan Orogeny as an example
Geological Magazine, 2019AbstractAnalysis of the distribution of detrital zircon grains is one of the few parameters by which Precambrian palaeogeography may be interpreted. However, the break-up of Pangea and the subsequent dispersal of some of its fragments around the Indian Ocean demonstrate that zircon analysis alone may be misleading, since zircons indicate their original
W. Franke, L.R.M. Cocks, T.H. Torsvik
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Extensional perpendicular orthogonal quartz veins related to early Variscan Orogeny
Journal of Structural GeologyOrthogonal sets of veins perpendicular to the bedding occur in fold-and-thrust belts; however, the timing of their formation remains unclear in relation to orogeny. This study aims to explain the development of perpendicular orthogonal vein sets from the iconic outcrops at northern Almograve in southwestern Portugal also known as “Chocolate-Tablet ...
Jeroen Van Der Lubbe +2 more
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TectonicsAbstract Relamination is closely connected to subduction zones. Despite the numerous high‐P metamorphic belts recognized on Earth, relamination remains a poorly documented process. We present a continental subduction zone where the exhuming high‐P rocks became a relaminant under the upper plate.
FRANCISCO J Rubio Pascual +2 more
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Colliding cratons: linking the Variscan Orogeny in West Africa and North America
Geological Society, London, Special Publications, 2023Abstract The Variscan Orogen was formed during the closure of the Rheic Ocean and the final collision between the North American and West African cratons in the Late Paleozoic. This collision led to the multistage building of the Mauritanide Belt to the east of the Variscan suture and to the building of the well ...
Michel Villeneuve +4 more
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Extent and Role of Cratonic Lithosphere in the Variscan Orogeny
ElementsThick and relatively cold cratonic lithosphere of Laurussia and Gondwana shaped the Variscan orogen as those continents collided diachronously to form Pangaea. Herein, we summarize and integrate geological and geophysical results that show how cratonic lithosphere of those composite continents created the Variscan geologic foundation of Europe and ...
Mazur, Stanislaw +4 more
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