The mountains of North-East Greenland are not remnants of the Caledonian topography. A comment on Pedersen et al. (2012): Tectonophysics vol. 530–531, p. 318–330

Abstract

Pedersen et al. (2012) suggest that the present-day mountains in North-East Greenland represent remnants of the original Caledonian topography modified during early rifting, and that the area has undergone slow, steady exhumation since ~250Ma. They base this hypothesis on inverse modelling calibrated by new apatite fission-track data from samples of exposed Caledonian basement. However, apatite fission-track data on their own register only cooling and must be integrated with geological evidence to reveal episodes of reheating, reflecting re-burial. The well-documented geological record of North-East Greenland shows that the Caledonian mountains were obliterated as topographic features during the late Palaeozoic and provides clear evidence of a history involving episodic, post-Caledonian exhumation and re-burial. The high-grade metamorphic basement was at great depth during the Devonian and was exhumed to the surface before being reburied by up to 2km of Upper Carboniferous and younger sediments. These sediments were then partially removed during renewed, Early–Middle Jurassic exhumation that led to the formation of a low-lying landscape which eventually subsided and was buried below a km-thick cover of Middle Jurassic and younger sediments. This cover was then partially removed during later phases of uplift and exhumation that eventually led to the formation of the present-day relief in post-Jurassic times. The geological record in East Greenland is incompatible with the idea of slow, steady exhumation since the Caledonian orogeny.