Rheic Ocean ophiolitic remnants in southern Iberia questioned by SHRIMP U-Pb zircon ages on the Beja-Acebuches amphibolites

摘要: [1] The Rheic Ocean was a major oceanic domain between Avalonia and Gondwana in Ordovician-Silurian times. Most of the Paleozoic plate reconstructions assume that suture lies within southern Iberia, coinciding with contact South Portuguese Zone Ossa-Morena Zone. This paper reports four Sensitive High Resolution Ion Micro-Probe (SHRIMP) U-Pb zircon ages from mid-ocean ridge basalt (MORB)-featured rocks Beja-Acebuches Amphibolite unit, which crops out along boundary Zone, is considered its most conspicuous unit. The obtained range 332 ± 3 to 340 4 Ma, corresponding crystallization mafic protoliths. These Early Carboniferous for amphibolites imply this unit can no longer be viewed as an ophiolite belonging suture, since presumably closed Devonian Tectonic joining single line Iberia either Lizard England or root zone Devonian/Ordovician ophiolitic units northwest must therefore reconsidered because age difference. We interpret represent narrow very ephemeral realm oceanic-like crust opened times, after total consumption Ocean. suggest mantle plume underneath times plausible large-scale geodynamic scenario formation these MORB-featured rocks.