RT Journal Article SR Electronic T1 Sea-floor spreading in the presence of the Iceland plume: the structure of the Reykjanes Ridge at 61°40′N JF Journal of the Geological Society JO Journal of the Geological Society FD Geological Society of London SP 1023 OP 1029 DO 10.1144/GSL.JGS.1995.152.01.24 VO 152 IS 6 A1 Smallwood, J. R. A1 White, R. S. A1 Minshull, T. A. YR 1995 UL http://jgs.lyellcollection.org/content/152/6/1023.abstract AB We present results from a combined normal incidence and wide-angle seismic survey of the Reykjanes Ridge at 61°40′N in the North Atlantic. The seismic data show that the crust is 8.4–10.0 km thick on the ridge axis. We attribute this thicker than normal oceanic crust to a high degree of melting caused by hot mantle from the Iceland plume beneath the speading centre. Layer 2A of the oceanic crust is significantly thicker at 0 Ma than in crust of age 4 Ma. Our results, combined with other seismic data from the North Atlantic, show that the crustal thickness decreases away from the plume centre to normal oceanic crustal thickness at a distance of approximately 1000 km.