Three main ductile deformations, D1-D3, and contemporaneous and later shear zones account for most structures in Central Lapland. The oldest tectono-metamorphic feature is the bedding-parallel, mostly microscopic S1, overprinted by the main foliation S2, which is the most prominent structural feature seen in almost all rock types throughout the study area. Subhorizontal S2 is an axial plane foliation to tight or isoclinal, inclined to recumbent F2 folds. Kinematic indicators in the central and southern parts of the study area indicate a northward transport direction, but close to the S and SW border the Lapland Granulite Belt it may be of opposite direction. F3 folds deform the D2 structures. F3 folding show an extreme variety regarding the fold vergence with N-vergent folds in south, SW-W-vergent folds in north and E-vergent folds in west close to the Kolari shear system. Apparently, the F3 folding seems to be associated with complex tectonic movement directions, from S to N direction in the south, from NE to SW in the north and northeast part, and from W to E in the western part of the study area. Several metamorphic zones have been mapped in the area. These are I) granulite facies migmatitic amphibolites south of the granulite complex (including the so called Tanaelv belt next to the granulites); II) high pressure mid-amphibolite facies rocks south of Zone I, characterised by garnet-kyanite-biotite-muscovite assemblages with local migmatisation in metapelites, garnet-hornblende-plagioclase assemblages in mafic rocks, local cordierite-orthoamphibole rocks intercalated with mafic volcanics; III) low-pressure mid-amphibolite facies rocks south of Zone II, garnet-andalusite-staurolite- chlorite-muscovite assemblages with retrograde chloritoid and kyanite in metapelites, hornblende-plagioclase-quartz±garnet in metabasites; IV) greenschist facies rocks of the Central Lapland Greenstone Belt, fine-grained white mica-chlorite-biotite-albite-quartz in metapelites, actinolite-albite-chlorite-epidote-carbonate in metabasites; V) prograde metamorphism south of Zone IV from lower amphibolite facies (andalusite-kyanite- staurolite-muscovite-chlorite±chloritoid schists, V.1-2) to mid-amphibolite facies (kyanite-andalusite-staurolite-biotite-muscovite gneisses, V.3) and upper amphibolite facies garnet-sillimanite-biotite gneisses (V.5); VI) amphibolite facies pluton-derived metamorphism related with heat flow from central and western Lapland granitoids, where Zone VI.2 represents both andalusite and sillimanite-present, and Zone VI.3 only sillimanite-present, andalusite absent gneisses. Pelitic rocks exhibit decompressional PT paths where andalusite grade metamorphism was preceded by higher pressure. Metamorphism was partly related with tectonic thickening during overthrusting of the Lapland Granulite Belt to the south, but the present metamorphic structure may record later, postmetamorphic faulting and folding events.</p
