1. A 19 to 17 Ma amagmatic extension event at the Mid-Atlantic Ridge: Ultramafic mylonites from the Vema Lithospheric Section Cipriani, Anna; Bonatti, Enrico; Seyler, Monique; Brueckner, Hannes K.; Brunelli, Daniele; Dallai, Luigi; Hemming, Sidney R.; Ligi, Marco; Ottolini, Luisa; Turrin, Brent D. 2009 Articles GeochemistrySubmarine geologyMetamorphic rocksMylonitePeridotite