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The Zarza la Mayor and Zarza de Montánchez tonalites and Arroyo de la Luz granodiorite are part of a tonalitic–granodioritic belt located along the Schistose-Greywacke Domain of the Central Iberian Zone. These intrusions are also part of the Central Extremadura Batholith, a set of plutons ranging from tonalite to leucogranite that have been considered a prime example of Variscan syn-kinematic plutonism. New LA-ICP-MS and CA-ID-TIMS U–Pb dating reveals that the Zarza la Mayor tonalite–granodiorite is an Early Ordovician intrusion. The LA-ICP-MS data show that there is an absence of inherited cores, despite some complex internal zoning with obvious resorption features in some of the zircon crystals. Dating of monazite and zircon by CA-ID-TIMS provides a concordant age of 478.1 ± 0.8 Ma. This age coincides with electron microprobe analysis (EMPA) monazite chemical ages for the Zarza de Montánchez (482 ± 10 Ma) and Arroyo de la Luz (470 ± 15 Ma) intrusions. These new data indicate the presence of an Early Ordovician belt of calc-alkaline tonalite–granodiorite in the Schistose-Greywacke Domain – the Beira Baixa–Central Extremadura tonalite–granodiorite belt – which resembles a continental magmatic arc. This belt is contemporaneous with the Ollo de Sapo magmatic event further north in the Central Iberian Zone.

Resumen: Durante el Neoproterozoico tardío y el Paleozoico, el actual segmento argentino-chileno de la Cordillera de los Andes y desde finales del Paleozoico la Península Antártica, formaron parte del margen suroccidental de Gondwana. Durante este periodo de tiempo, a dicho margen se fue acrecionando un conjunto de fragmentos continentales de tamaño y aloctonía variable, dando lugar en el Paleozoico a seis orogenias de diferente extensión temporal y espacial: Pampeana (Ediacárico-Cámbrico temprano), Famatiniana (Ordovícico Medio-Silúrico), Chánica (Devónico Medio-Carbonífero temprano), Oclóyica (Ordovícico Medio-Devónico), Gondwánica (Devónico Medio-Pérmico medio) y Tabarin (Pérmico tardío-Triásico). Todas estas orogenias son colisionales, salvo la Tabarin y la Gondwánica al sur de los 38º S.Palabras clave: Evolución geodinámica, Paleozoico, Andes argentino-chilenos, Península Antártica, Orógeno Oclóyico, Orógeno Famatiniano, Orógeno Chánico, Orógeno Gondwánico, Orógeno Tabarin.Abstract: During the late Neoproterozoic and Paleozoic times, the Argentine-Chilean Andes, -and since the late Paleozoic the Antarctic Peninsula,- formed part of the southwestern margin of Gondwana. During this period of time, several continental fragments of variable extensión and allochtonie were successively accreted to that margin, resulted in six Paleozoic orogenies of different temporal and spatial extension: Pampean (Ediacaran-early Cambrian), Famatinian (Middle Ordovician-Silurian), Chanic (Middle Devonian-early Carboniferous), Ocloyic (Middle Ordovician-Devonian), Gondwanan (Middle Devonian-middle Permian) and Tabarin (late Permian-Triassic). All these orogenies had a collisional character, with the exception of the Tabarin and the Gondwanan south of 38º S.Keywords: Geodynamic evolution, Paleozoic, Argentine-Chilean Andes, Antarctic Peninsula, Ocloyic orogen, Famatinian orogen, Chanic orogen, Gondwanan orogen, Tabarin orogen.

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