Local lithospheric relief associated with fracture zones and ponded plume material

摘要: [1] Buoyant plume material ponds at the base of oceanic lithosphere. It is a natural probe for relief on lithosphere owing to plate age because it flows laterally along an upside-down drainage pattern. Geomorphic and geochemical studies near-ridge on-ridge hot spots indicate, as expected, that thickens ages. Corridors thin channel axis, while thick end ridge segments dams this along-axis flow. Channel extend from plumes toward axes. However, good correlation between local lithospheric thickness not evident fracture zones within old ocean basins. Such would be expected if cooled only by conduction. Then pressure-release melting volcanoes occur preferentially near where cascades young This concentration volcanic edifices does occur. lack consequence small-scale convection Scaling relationships numerical models indicate modestly vigorous several milliwatt per meter squared sufficient perturb beneath without changing gross with age. Typically, step in moves side zone.