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Intra-crustal recycling and crustal-mantle interactions in
Chichorro, Martim; Sola, Rita; Pereira, M. Francisco; Sanchez-Garcia, Teresa; Ferreira, Antonio; Silva, Jose Brandao; Armstrong, RichardIn situ O-isotope compositions of detrital, inherited and melt-precipitated zircons with Neoproterozoic to Ordovician ages are presented to assess the crustal evolution of the North Gondwana margin. Different groups of pre-Mesozoic rocks from SW Iberia were targeted: i) Ediacaran paragneisses and meta-greywakes of the Ossa-Morena Zone – the Serie Negra Group deposited at ~ 560 Ma in a Cadomian magmatic arc sett...
Diachronism in the late Neoproterozoic–Cambrian arc-rift transition of North Go...
Alvaro, J.Javier; Bellido, Felix; Gasquet, Dominique; Pereira, M. Francisco; Quesada, Cecilio; Sanchez-Garcia, TeresaIn the northwestern border of the West African craton (North Gondwana), a transition from late Neoproterozoic subduction/collision to Cambrian rift processes was recorded in the Anti-Atlas (Morocco) and in the Ossa-Morena Zone (Iberia). Cambrian rifting affected both Pan-African and Cadomian basements in a stepwise and diachronous way. Subsequently, both areas evolved into a syn-rift margin episodically punctua...
New geochemical and geochronological data of early Cambrian of (SW Iberia): Cal...
Sanchez-Garcia, Teresa; Pereira, M. Francisco; Bellido, Felix; Chichorro, Martim; Silva, J. Brandao; Valverde-Vaquero, Pablo; Pin, Christian; Solá, RitaThe Ossa-Morena Zone (SW Iberia) displays a well-preserved record of the history of the northern Gondwana margin in Late Ediacaran-Early Cambrian times. This period of time is marked by the late-stage evolution of the Cadomian magmatic arc and related back-arc basins (c. 590-545 Ma), and the onset of rifting and widespread magmatism (c. 530-500 Ma) that led to the opening of the Rheic Ocean. Here we present new...
Rift-related volcanism predating the birth of the Rheic Ocean
Sanchez-Garcia, Teresa; Bellido, Felix; Pereira, M. Francisco; Chichorro, Martim; Quesada, Cecilio; Pin, Christian; Silva, Jose B.Two very different periods of magma emplacement in the crust of the Ossa-Morena zone (early and main events) in SW Iberia have been previously interpreted to record a Cambrian/Early Ordovician rifting event that is thought to have culminated in the opening of the Rheic Ocean during the Early Ordovician. New stratigraphic, petrographic, geochemical and Sm–Nd isotope data from Cambrian volcanic rocks included in ...