SAUNDERS, A. D. & NORRY, M. J. Introduction • GASS,I. G. Magmatic processes at and near constructive plate margins as deduced from the Troodos (Cyprus) and Semail Nappe (N Oman) ophiolites • WHITE, R. S. Asthenospheric control on magmatism in the ocean basins •SPRAY, J. G. Upper mantle segregation processes: evidence from alpine-type peridotites • NATLAND, J. H. Partial melting of a lithologically heterogeneous mantle: inferences from crystallization histories of magnesian abyssal tholeiites from the Siqueiros Fracture Zone • DICK, H. J. B. Abyssal peridotites, very slow spreading ridges and ocean ridge magmatism • BLOOMER, S. H., NATLAND, J. H. & FISHER, R. L. Mineral relationships in gabbroic rocks from fracture zones of Indian Ocean ridges: evidence for extensive fractionation, parental diversity, and boundary-layer recrystallization • ELTHON, D. Pressure of origin of primary mid-ocean ridge basalts • Fum, T. Genesis of mid-ocean ridge basalts • PALACZ, Z. A. & WOLFF, J. A. Strontium, neodymium and lead isotope characteristics of the Granadilla Pumice, Tenerife: a study of the causes of strontium isotope disequilibrium in felsic pyroclastic deposits • STOREY, M., WOLFF, J. A., NORRY, M. J. & MARRINER, G. F. Origin of hybrid lavas from Agua de Pau volcano, Sao Miguel, Azores • THOMPSON, G., BRYAN, W. B. & HUMPHRIS, S. E. Axial volcanism on the East Pacific Rise, 10-120 N • HELGASON, J. The Fjallgardar volcanic ridge in NE Iceland: an aborted early stage plate boundary or a volcanically dormant zone? • FLOYD, P. A. Geochemical features of intraplate oceanic plateau basalts • DAVIES, G. R., NORRY, M. J., GERLACH, D. C. & CLIFF, R. A. A combined chemical and Pb-Sr-Nd isotope study of the Azores and Cape Verde hotspots: the geodynamic implications • CHAFFEY, D. J., CLIFF, R. A. & WILSON, B. M. Characterization of the St Helena magma source • JORON, J.-L. & TREUIL, M. Hygromagmaphile element distributions in oceanic basalts as fingerprints of partial melting and mantle heterogeneities: a specific approach and proposal of an identification and modelling method • FISHER, D. E. Evaluation of rare gas data in relation to oceanic magmas • SUN, S.-S. & McDONOUGH, W. F. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes • MURTON, B. J. Tectonic controls on boninite genesis • Index