Comment on 'Rheic Ocean ophiolitic remnants in southern Iberia questioned by SHRIMP U-Pb zircon ages on the Beja-Acebuches amphibolites' by A. Azor et al

摘要

[1] In a recent contribution, Azor et al. [2008] present new U-Pb zircon age data obtained with the Sensitive High Resolution Ion Microprobe (SHRIMP) technique on four mafic rocks from the so-called Beja-Acebuches amphibolites (BAA) unit, believed to delineate a major suture between the Ossa-Morena Zone (OMZ) and the South Portuguese Zone (SPZ) of the Iberian Variscides. On the basis of their geochronological results, interpreted to reflect igneous crystallization of mid-ocean ridge basalt (MORB)-featured mafic protoliths from 332 ± 3 to 340 ± 4 Ma, Azor et al. (paragraph 1) conclude that the Beja-Acebuches amphibolite unit represents "a narrow and very ephemeral realm of oceanic-like crust that opened in Early Carboniferous times" as a result of the involvement of "a mantle plume underneath southern Iberia."