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Showing 1 to 20 of 30 for “"Variscan"”.
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Oroclines of the Iberian Variscan belt: Tectonic and paleogeographic implications
The Western European Variscan orogenic belt is thought to represent the final in a series of Paleozoic continental collisions that culminated with the amalgamation of the supercontinent Pangea. The Iberian segment of the Variscan belt is characterized by Cantabrian orocline, which is 180º and …
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Geochemistry of Variscan lamprophyre magmatism in the Saxo-Thuringian Zone
… of lamprophyres in the Saxo-Thuringian Zone of Variscan Central Europe, which are useful to track the variable effects of the Variscan orogeny on local mantle evolution. This work presents and evaluates the mineralogical, geochemical, and Sr-Nd-Pb isotopic data of late-Variscan calc-alkaline …
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Topographic reconstructions of the Variscan Belt of Western Europe through the study of fossil hydrothermal systems
… isotope quantification of paleoaltimetry for the Variscan Belt of Western Europe that integrates late-Carboniferous hydrogen isotope ratios of meteoric water in the internal zones in the Armorican Massif (AM) and the French Massif Central (FMC) with age-equivalent precipitation records in the …
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Mineral, fluid and thermal evolution in veins from late orogenic coal basins of the Cantabrian Zone (Variscan, NW Spain)
… pull-apart coal basins (Cantabrian Zone, Variscan of NW Spain) are investigated. These bedding perpendicular fissures (cm-wide) formed in sandstones synchronous with folding and faulting during bedding-parallel slip. Three stages of infilling and mineral growth are recognised within the …
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Structural development of a volcanic sequence of the Lahn area during the Variscan orogeny in the Rhenohercynian Belt (Germany)
… very low- to low-grade metamorphism during the Variscan orogeny. The field structural data analysis: Bedding and s1-cleavage relationships show a clear NW vergence, in which s1-cleavage is steeper. s2-cleavage (s1-cleavage folding) occurs as kinking and buckling. Intersection lineations are …
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Eo-Variscan Orogenesis in the Guilleries Massif, Catalan Coastal Ranges, Northeastern Spain Recorded by U-Th-Pb ages of Monazite Inclusions in Metamorphic Garnet
<p>A chronicle of the Variscan Orogeny is recorded in high grade pelitic schists of the Guilleries Massif of the Catalan Coastal Ranges of northeastern Spain which preserve multiple rounds of deformation and metamorphism. The massif records a classic Variscan low-pressure and high-temperature …
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Metallogenesis of Cu deposits in Upper Palaeozoic sedimentary rocks, southern Ireland
… faults that pre-date the late Carboniferous Variscan Orogeny. The copper sulphide bearing, mainly E-W to ENE-WSW striking, quartz veins are directly associated with these extensional faults. This early vein system experienced subsequent late Carboniferous deformation during the Variscan …
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Zircon U-PB and LU-HF isotopic data from some peri-gondwana variscan terranes (Sardinia-Corsica block and calabropeloritan arc): new insights on the cenozoic geodynamic evolution of the central mediterranean basin
The reconstruction of pre-Variscan plates configuration in the Mediterranean area, is still poorly understood. Different hypotheses have been proposed to explain the relationships between peri-Tyrrhenian blocks such as Sardinia-Corse block (SCB) and Calabrian-Peloritain Arc (CPA), which before the …
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Innovative numerical petrological methods for definition of metamorphic timescale events of southern European Variscan relicts via thermodynamic and diffusion modelling of zoned garnets
In questo lavoro sono stati sviluppati e applicati a due casi studio dei metodi innovativi di petrologia numerica, utilizzando diversi linguaggi informatici di programmazione (Model Builder; Python; Matlab), con l intento di studiare le proprietà chimico-fisiche delle rocce metamorfiche alla …
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Neoproterozoic to Holocene tectonothermal evolution of the southern Cantabrian Mountains NW Iberia, revealed by apatite fission-track thermochronology
… having experienced uplift coeval with alpidic, Variscan and in the south, possibly Cadomian orogenic cycles; these rocks are referred to by their Variscan tectonic expressions: the Cantabrian Zone and Narcea Antiform. This thesis yields new experimental and geologic information from 32 AFT …
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Large-scale hydrothermal dolomitisation in the southwestern Cantabrian Zone (NW Spain) : causes and controls of the process and origin of the dolomitising fluids
… in NW Spain represents the foreland belt of the Variscan Iberian Massif and is made up of a Precambrian basement covered by Palaeozoic sediments. This succession was thrusted and folded in Late Carboniferous time during the Variscan Orogeny, resulting in several thin-skinned thrust units. The …
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Paleomagnetic and mineral magnetic studies of zinc-lead ore deposits in the Metaline (Washington state, USA) and Midlands (Ireland) ore fields
… postdate the Asturian deformational phase of the Variscan orogeny and suggest an entirely epigenetic Variscan model of ore genesis in which the mineralization event occurred during the cooling from the regional Variscan thermal episode.
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A seismic study on the structural evolution of the North Celtic Sea Basin, offshore Ireland
… was accommodated by several reactivated Variscan thrust faults with a detachment between the upper and lower crust at 18-20 km (11-12.5 miles) depth. Rifting continued through the Lower Jurassic and extension was accommodated primarily on the most northern of the reactivated Variscan …
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Cordierite and its retrograde breakdown products as monitors of fluid-rock interaction during retrograde path metamorphism : case studies in the Schwarzwald and the Bayerische Wald (Variscan belt, Germany)
Retrograde breakdown products of cordierite are commonly termed pinite, but their modes, compositions and formation conditions are only poorly known. A systematic study on pinitised cordierite from high-temperature metamorphic pelites of the Schwarzwald and the Bayerische Wald using electron …
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Numerical Modeling as a Means to Enhance Genetic Sedimentary Basin Interpretation : A Case Study of the Southern Cantabrian Basin (NW Spain)
… planes by thin-skinned tectonics within the Variscan fold-and-thrust belt. In order to carry out stratigraphic modeling, structural balancing was employed to determine initial distances between the recorded stratigraphic columns. Surface data only were available, therefore a family of …
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Integrated numerical modelling of a polyhistory basin, Southern Cantabrian Basin (Palaeozoic, NW-Spain)
… the Southern Cantabrian Basin, which is the Variscan foreland fold-and-thrust belt of NW Spain. Structural balancing offers approximations of predeformational, spatial relationships between measured cross-sections. It provides information about minimal basin shortening and Late Devonian basin …
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A study of the structure of the Belgian crust by Moho determination and local seismic tomography
… being upthrusted in the middle crust during the Variscan Orogeny. Superficial geology is also recognizable, like the BM, the AA, the Rocroi and Stavelot Inliers, the sediment infill of the RVG and the Trier Graben. There is a velocity contrast over the entire crust between the AA and the BM. The …
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INTO THE STRUCTURE OF THE PERMIAN DEEP CONTINENTAL CRUST: A MULTISCALE APPROACH TO RECONSTRUCT MIGMATIZATION IN THE VALPELLINE SERIES (DENT BLANCHE TECTONIC SYSTEM, WESTERN ITALIAN ALPS)
… mantle and deep crust. During the Permian, the Variscan lithosphere was affected by extension due to the Pangea break up followed by Tethys opening. This Thesis investigates the evolution of the Valpelline Series in the Dent-Blanche Tectonic System (Western Italian Alps) which represents an …
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