Gradualism is again taken for granted, even in catastrophic events. If Greenland was to travel across a semi molten media what would one think of the "interruption in sedimentation", as you put it? An event to provoke continental motions on earth had to be a very destructive and utterly erasing process that could have led to our modern continental configuration. The dating system would in really be telling how old a recently metamorphosed rock is, again, especially the oceanic floor.
Speaking of sedimentation, i read recently on an article that there was a Greelandic Quaternary interglacial period:
This shows that you do not understand plate tectonics at all. The continents do not drift. They are carried by plates. If the plate melts then the continents are not moved by the molten plate. The evidence is very clear that the plate has not melted. Sedimentation and paleomagnetism make that abundantly clear. And that is based on real evidence.