Generación de litosfera oceánica en ciclos de 100 Ma en peri-GondwanaOfiolitas de Marruecos e Iberia
- R. Arenas 1
- S. Sánchez Martínez 1
- R. Albert 2
- F. Haissen 3
- J. Fernández-Suárez 1
- N. Pujol-Solà 4
- P. Andonaegui 1
- R. Díez Fernández 1
- J.A. Proenza 4
- A. Garcia-Casco 5
- A. Gerdes 2
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1
Universidad Complutense de Madrid
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- 2 Institut für Geowissenschaften, Goethe-University Frankfurt
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3
Université Hassan II de Casablanca
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4
Universitat de Barcelona
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5
Universidad de Granada
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ISSN: 1576-5172
Ano de publicación: 2021
Título do exemplar: X Congreso Geológico de España
Número: 18
Páxinas: 1041
Tipo: Artigo
Outras publicacións en: Geotemas (Madrid)
Resumo
The Variscan Orogen in Iberia and the Anti-Atlas mountains in Morocco contain a set of ophiolites formed between Neopro- terozoic and Devonian times during the complex evolution of the NW African margin of Gondwana. During this time interval the margin evolved from an active margin (c. 750-500 Ma, the Avalonian-Cadomian arc), to the final collision with Laurussia to form Pangea. In this context, different ophiolites have been dated at c. 700, 600, 500 and 400 Ma. The composition of all these peri-Gondwanan ophiolites is of supra-subduction zone type, showing no evidence for preserved MORB-type oceanic lithosphere. Consequently, these ophiolites were generated in the peri-Gondwanan realm during the opening of fore-arc or back-arc basins. The peri-Gondwanan realm has been a domain where generation of oceanic or transitional lithosphere seems to have occurred at intervals of c. 100 Ma. These regularly spaced time intervals may indicate cyclic events of mantle upwelling in the peri-Gondwanan mid-ocean ridges, with associated higher subduction rates at the peri-Gondwanan tren- ches and concomitant higher rates of partial melting in the associated mantle wedges.