In the Archaean, the first basaltic crust of the Earth turned into a thickening continental TTG (tonalite-trondhjemite-granodiorite) crust. Despite many decades of TTG investigations, the researchers have not yet agreed upon the tectonics behind the conversion, and several scenarios such as stagnant lid, plume, and arc tectonics are under debate. However, the research has not focused that much on the migmatitic nature of the TTG-amphibolite associations that often form an essential part of the TTG crust. Understanding the origin of this association is an important factor in understanding the formation of the early protocontinents. This ongoing project will provide structural, geochemical and geochronological results from two less-studied TTG-amphibolite complexes in Finnish Lapland, the Mesoarchean Rommaeno complex (3.2 Ga) of the Norrbotten Province and Neoarchaean Lake Inari Complex of the Kola Province. Both complexes consist of folded and banded TTG gneisses with abundant amphibolite enclaves. Amphibolites show in situ melting structures and metatexite-diatexite transitions forming a boundless interconnected network. The geochemical results from Lake Inari confirm the bimodality of the tonalite-basalt association as well as the intermingled combination of low- and high-HREE TTGs. Variable HREE content is a typical feature for TTGs. The amphibolites are basalts in TAS classifications and show flattish REE patterns. Two geochemical endmembers of TTGs can be identified within the Lake Inari area, one with depleted HREE and low Mg content and the other with high HREE and elevated Mg content. Both these types seem to be coeval and intermingling, which could be explained by mixing of local metatexite melts with diatexite melts from garnet-bearing granulite facies layers. The amphibolites represent oceanic plateau type basalts. The best-fit explanation for the origin of the TTG gneiss complexes in Finnish Lapland is in situ and in-source partial melting of basalts in the deep parts of a thick oceanic plateau.