The importance of along-margin terrane transport in northern Gondwana: insights from detrital zircon parentage in Neoproterozoic rocks from Iberia and Brittany
Detrital zircons from late Neoproterozoic rocks of the peri-Gondwanan Cadomian belt of SW Iberia and north Armorican Domain of Brittany record Neoproterozoic (ca. 860-550 Ma), Palaeoproterozoic (ca. 2300-1800) and Archaean (ca 3300-2600 Ma) U-Pb ages. The absence of Mesoproterozoic zircons suggests...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2002 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/60433 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/60433 |
| Access Level: | acceso abierto |
| Palabra clave: | 551.2 U-Pb dating 213 nm laser ablation ICP-MS Zircon Armorica Iberia Gondwana Geodinámica Petrología 2507 Geofísica |
| Sumario: | Detrital zircons from late Neoproterozoic rocks of the peri-Gondwanan Cadomian belt of SW Iberia and north Armorican Domain of Brittany record Neoproterozoic (ca. 860-550 Ma), Palaeoproterozoic (ca. 2300-1800) and Archaean (ca 3300-2600 Ma) U-Pb ages. The absence of Mesoproterozoic zircons suggests that these terranes evolved in a peri-W African realm. This is in contrast to other western European terranes that preserve Mesoproterozoic zircons and are likely to have evolved in a peri-Amazonian realm. Such a contrast in detrital zircon populations, coupled with the presence of Mesoproterozoic zircons in the Ordovician Armorican quartzite, deposited in a peri-African platform, is interpreted to record along-margin terrane transport. The change in provenance suggests that subduction was replaced by transform faults that juxtaposed Amazonia-derived terranes against W Africa-derived terranes to form the Avalonia and Armorica microcontinents. Subsequent extension along the margin resulted in the birth of the Rheic Ocean and the outboard drift of Avalonia. |
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