Tectonostratigraphy of the Mérida Massif reveals a new Cadomian suture zone exposure in Gondwana (SW Iberia)

[EN] Neoproterozoic and Palaeozoic rocks of the Mérida Massif (SW Iberia) have been grouped into tectonostratigraphic units. Each unit is separated from the rest ones by either crustal-scale thrusts and/or extensional detachments. The lowermost unit (Magdalena Gneisses; lower plate) has continental...

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Detalles Bibliográficos
Autores: Díez Fernández, Rubén, Arenas, Ricardo, Rojo-Pérez, E., Sánchez Martínez, Sonia, Fuenlabrada, J.M.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/269726
Acceso en línea:http://hdl.handle.net/10261/269726
Access Level:acceso abierto
Palabra clave:Cadomian tectonics
Suture zone
Ophiolite
Variscan tectonics
SW Iberian Massif
Descripción
Sumario:[EN] Neoproterozoic and Palaeozoic rocks of the Mérida Massif (SW Iberia) have been grouped into tectonostratigraphic units. Each unit is separated from the rest ones by either crustal-scale thrusts and/or extensional detachments. The lowermost unit (Magdalena Gneisses; lower plate) has continental crust affinity, and rest below a mafic-ultramafic ensemble, referred to as the Mérida Ophiolite (suture zone). The Serie Negra Group constitutes a unit with continental crust affinity (Upper Schist-Metagranitoid Unit; upper plate) located on top of the Mérida Ophiolite. A carbonate-rich succession (Carija Unit) occupies the uppermost structural position. Structural and previous isotopic data suggest that this suture zone was formed during the Cadomian Orogeny. Superimposed shortening during the late Palaeozoic formed upright to NE-verging folds and thrusts that affected this suture zone and juxtaposed it onto Ordovician strata during the Variscan Orogeny. The Mérida Ophiolite represents a new Cadomian suture zone exposure in the Gondwanan realm of the Iberian Massif, but its root zone is yet to be identified. This ophiolite shares a far-travelled nature with other Cadomian and Variscan suture zone exposures in Iberia, making the latter a piece of lithosphere built through inland transference of allochthonous terranes from peri-Gondwana onto mainland Gondwana during the Neoproterozoic-Cambrian and the Devonian-Carboniferous periods.