Different polar wandering paths seen in rocks of different continents. Magnetic reversal time scale - Pattern of reversals in sea floor basalts matches known reversal time scale as determined from rocks exposed on land. Width of magnetic stripes on sea floor is related to time. In 1962, Harry Hess proposed the hypothesis that midocean ridges represent narrow zones where ocean crust forms. Spreading centers Mantle material moves upward, carrying heat.
Heat causes expansion and rising of sea floor.
Convection in the mantle drives the system Large scale thermal convection in the mantle. If the rising part of a convection cell is beneath a continent, it will cause it to RIFT apart. Also causes seafloor to rift apart at mid-ocean ridge. Continents move alont with ocean crust, and do not plow through it. Many seemingly unrelated geologic facts are unified by the plate tectonic theory.