8. The Mechanics of the ‘Subduction’ Start Process Sequence
Subduction will start the moment two plates collide against each other. In section 7 above it was demonstrated that oceanic plate-to-oceanic plate will ultimately result in continental-to-continental plate collision. Thus, by inference continental plate-to- oceanic plate collision in an intermediate stage. This section will examine in depth the actual mechanics that result in subduction of the oceanic crust intermediate stage (fig 6b). Current wisdom displays the oceanic lithosphere as preferentially subducting under the continental plate and in doing so is shown to be responsible for the orogenic and volcanic arc activity on the uppermost continental plate. The calculations (sections 5&6) relating to the circumferential forces demonstrate the continental crust moving over the oceanic crust.