At http://malagabay.wordpress.com/2014/04/20/greenland-raised-beaches-II/ … in his first post he suggested Greenland bedrock has tilted uniformly but is fractured at some point. This is further indicated as in the south of Greenland sea levels are rising – drowning Inuit ruins of Late Holocene age.
In this second post Tim Cullen concentrates on northern Greenland and concludes the bedrock here was uplifted catastrophically on the evidence of alternating levels of clay and raised beaches (formed of gravels and pebbles). In other words, the far north is raised some 200m in such a catastrophic manner that an additional 200m of clay, gravel, and pebbles, was deposited (presumably by tidal waves).