gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1998.62A.2.285 Explosive Activity on the Ocean Floor: Purely Magmatic or Magma-Seawater Interaction Origin? Geochemical and Isotopic Arguments Pineau F. Shilobreeva S. Javoy M. Laboratoire de Géochimie des Isotopes Stables, IPGP, Université de Paris 7 Denis Diderot, ESA CNRS 70-47, 4 place Jussieu, 75 252, Paris, cedex 05, France Hékinian R. Bideau D. Département de Géoscience Marine, IFREMER, centre de Brest, DRO/GM, BP 37, 29 287 Plouzané, France 1998 62A 2 1184 1185 Copyright © 1998, The Mineralogical Society 1998