An overview of the Emperor chain & lateral flow of plume material with the Euterpe chain; The lateral flow of plume material in the northern Pacific.

Norman Sleep

Geophysics Department, Stanford University, Stanford, CA 94305-2215


Lateral flow of plume material is a widespread but poorly recognized and understood process.  Many of the objections to plumes result because we do not yet understand the local kinematics and the general dynamics of this process. Conversely, plume material is a natural probe for the base of the lithosphere.  Plume material flows laterally from thick lithosphere to thin.  The base of the lithosphere is an upside-down drainage pattern. An interesting application is that the escarpment in the lithosphere beneath oceanic fracture zones retreats to the old side due to stagnant-lid convection.  Seamounts associated with melting where plume material cascades over lithospheric escarpments are thus not obviously associated with surface fracture zones.  A group of more complicated features are flowline hotspots on oceanic crust.  They can from when ponded plume material beneath a continent crosses a passive margin or from viscous fingering effects beneath oceanic lithosphere.  The dynamics of the latter process are fully 3D. Much of our effort will continue to be directed toward real examples, which effect surface geology.