Evidence from Islands on the Spreading of Ocean Floors

Fernandina Volcano's evolved, well‐mixed basalts: Mineralogical and petrological constraints on the nature of the Galapagos plume

“…The association of deep-seated mantle plumes with longlived chains of seamounts and volcanic islands is now well accepted [Wilson, 1963;Morgan, 1972;Sleep, 1990Sleep, , 1992. The initial impact of mantle plume heads upon lithosphere often results in massive amounts of decompressive basaltic volcanism, forming large igneous provinces (LIPs) that include oce- Recent geochemical studies of the Galftpagos archipelago have stressed the complex nature and chemistry of its volcanism as well as its broad geographical extent (Figure 1) [Geist et al, 1988;Geist, 1992;White et al, 1993;Harpp, 1995;Harpp and Geist, 1998].…”

Thermal convection and the origin of ice streams

“…This kind of convection in ice sheets has similarities with the view of thermal convection in Earth's mantle advanced by Wilson (1963Wilson ( , 1965Wilson ( , 1966. His lithosphere plates advecting horizontally above his convecting mantle would correspond to a cold ice ceiling advecting above a warm ice basement.…”

“…His lithosphere plates advecting horizontally above his convecting mantle would correspond to a cold ice ceiling advecting above a warm ice basement. Lithosphere 'hot spots' correspond to basaltic convection plumes rising from the deep mantle that turn on and off, and when turned on may punch through the lithosphere to produce volcanoes, such as the Hawaiian volcanic chain (Wilson, 1963), when partial melting occurs at the top of a plume. The ceiling of cold ice in polar ice sheets is much too thick to be penetrated by rising plumes of warm basement ice, but the idea of thermal convection in a warm polycrystalline mantle, whether of basalt rock or ice, is the central concern.…”

“…He published three brief papers in those early years that were seminal. Wilson (1963) proposed deep-mantle thermal convection that sent plumes punching through a spreading Pacific lithosphere plate to account for the age of volcanoes in the Hawaiian island chain. Wilson (1965) proposed transform faults that connected oceanic rifts to oceanic trenches, thereby showing that Earth's lithosphere consisted of interacting moving tectonic plates.…”

Thickness Of The Earth's Crust Beneath The Pacific-Antarctic Ridge

“…Models involving convection currents of large dimensions in the mantle have been widely postulated (e.g., Menard, 1960Menard, , 1961Wilson, 1963). Theoretical objections to such convection currents have been raised by Munk and MacDonald (1960), however, and no physical convection system has been proposed that is complex enough to account for all mid-oceanic ridges.…”