7 documents found, page 1 of 1
Birth and demise of the Rheic Ocean magmatic arc(s): Combined U–Pb and Hf isoto...
Pereira, Manuel Francisco; Gutierrez-Alonso, Gabriel; Murphy, J. Brendan; Drost, Kerstin; Gama, Cristina; Silva, J. BrandãoPaleozoic continental reconstructions indicate that subduction of Rheic oceanic lithosphere led to collision be- tween Laurussia and Gondwanawhich was a major event in the formation of the Ouachita-Appalachian-Variscan orogenic belt and the amalgamation of Pangea. However, arc systems which record Rheic Ocean subduction are poorly preserved. The preservation of Devonian detrital zircon in Late Devonian–Early Ca...
Sedimentary record of the amalgamation and break-up of Pangaea: U-Pb detrital z...
Pereira, M. Francisco; Chichorro, Martim; Gutierrez-Alonso, Gabriel; Gama, Cristina; Drost, Kerstin; Ribeiro, Carlos; Albardeiro, Luis; Hofmann, MandyIn SW Iberia there is a basal unconformity where Triassic sandstones overlie previously deformed Carboniferous turbidites. This important stratigraphic boundary records the transition from the final stages of Pangaea’s amalgamation to the initial stages of break-up. U-Pb dating of detrital zircon from Carboniferous greywackes of the South Portuguese Zone and Triassic sandstones of the Algarve and Alentejo basin...
Detrital zircon age constraints on the sediment provenance of Variscan basins i...
Pereira, M. Francisco; Chichorro, Martim; Johnston, Stephen; Gutierrez-Alonso, Gabriel; Silva, J. Brandão; Linnemann, Ulf; Hofmann, MandyThe mid- to late-Devonian Rheic suture between the Laurussia and Gondwana blocks that combined to form Pangea, can be traced along the Variscan orogenic belt across Western-Central Europe. In southwest Iberia, there are, however, no magmatic arc rocks that can be related to the closure, by subduction of its oceanic lithosphere, of the Rheic Ocean. The only magmatism recorded on both sides of the suture is of ea...
Pangaea amalgamation and break-up: new radiometric constraints on sediment prov...
Pereira, M. Francisco; Chichorro, Martim; Ribeiro, Carlos; Vilallonga, Filipa; Drost, Kerstin; Linnemann, Ulf; Hofmann, MandyThe subject of this provenance study are greywacke and sandstone strata that define a key unconformity in SW Iberia, where late Triassic strata (Algarve Basin) overlie previously deformed and metamorphosed late Carboniferous basement (South Portuguese Zone). This angular unconformity records the transition from Pangaea´s amalgamation to its break-up with: i) development of marine basins of Moscovian age with tu...
Denudation of SW Iberia during Pangea's break-up: geochemical and detrital zirc...
Pereira, M. Francisco; Ribeiro, Carlos; Vilallonga, Filipa; Chichorro, Martim; Drost, KerstinThis provenance study is mainly based on new whole-rock geochemistry data but also involves detrital zircon geochronology. More specifically, this study investigates the Early Mesozoic denudation of a Late Paleozoic mountain range and the coeval development of basins during Pangea break-up in SW Iberia. The relations with past dynamic Earth events in Western Europe also include the amalgamation of Pangea and th...
Relative timing of transcurrent displacements in northern Gondwana: U-Pb laser ...
Pereira, M. Francisco; Silva, J. Brandao; Drost, Kerstin; Chichorro, Martim; Apraiz, ArturoThe Variscan belt of Western and Central Europe was formed by the oblique subduction of the Rheic Ocean and the collision of Laurussia with Gondwana during the Late Palaeozoic. We present field relationships and new U–Pb LA-ICP-MS zircon and monazite ages for Variscan gneisses and granites from a key section of the western Iberian Massif. The Martinchel section records the interplay of two kilometre-scale Varis...
The Cadomian Orogeny and the opening of the Rheic Ocean: The diacrony of
Linnemann, Ulf; Pereira, M. Francisco; Jeffries, Teresa; Drost, Kerstin; Gerdes, AxelCadomian orogenic processes and their continuum to the opening of the Rheic Ocean were modeled by making use of new LA-ICP-MS U–Pb ages from detrital zircons of sedimentary rocks of Late Neoproterozoic (Ediacaran) and Cambro-Ordovician sediments of the Ossa-Morena Zone (Iberian Massif) compared with those from the Saxo-Thuringian Zones (Bohemian Massif). Presented data constrain a diachrony of Cadomian and rela...