"Subduction is the result of two tectonic plates converging, as one
plate, typically the oceanic plate, is forced down or subducted under
the less dense continental plate.... snipped ...The gravitational
pull of the denser oceanic plate drives the subduction."
http://www.utexas.edu/tmm/npl/minera...esis/index.htm

There we go, ..it's not me saying it, is it? "The floating plate with
the continent on it, forces the oceanic one without the continent on
it, down... ..and that oceanic one going down drives the subduction"
(and plate tectonics is subduction-driven.)

See? That's the University of Texas, who *know* what they're talking
about.

Dopey, ..huh?