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divergence zones (ridges)
2) Collision resistance not predicted (because convection
models do not predict plates of “plateness”. This results
from chemical differentiation and continent formation.
3) Ocean basins deviate from the age-2 relationship near
ridges (hydrothermal circulation?) and far from ridges
4) Dynamic topography, expected from mantle
heterogeneity, seems inconsistent. The South African
“superswell” makes sense, but some other areas of
expected dynamic topography have not been found. OCE 661 So where do we stand with
convection and plate tectonics.
And some things don’t work quite
so 1) Plate motion changes: Abrupt changes in plate motion,
such as the Hawaiian-Emperor bend, also reflected in
many other seamount chains on the Pacific Plate, seems
to require a 45 degree change in less than 5 my. How
does convection do this? Some have suggested that all
the hotspots changed direction simultaneously ins...
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This document was uploaded on 01/26/2014.
- Winter '14