%0 Journal Article
%A Fernández Suárez, Javier
%A Gutiérrez Alonso, Gabriel
%A Jeffries, Teresa E.
%T The importance of along-margin terrane transport innorthern Gondwana: insights from detrital zircon parentagein Neoproterozoic rocks from Iberia and Brittany
%D 2002
%@ 0012-821X
%U https://hdl.handle.net/20.500.14352/60433
%X 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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