the svecofennian orogen underwent a gravitational collapse from 1790 to 1770 million years ago. the late magmatism following the orogeny overlaps in time with the early magmatism of the transscandinavian igneous belt. this magmatism was largely the result of anatexis forming migmatites and large plutons. another characteristic of the late magmatism is the apparent lack of mafic and intermediate compositions among the magmas, which are nearly all felsic.