The Central Lapland Greenstone belt comprises rift-related metavolcanic and metasedimentary
rocks representing one of the largest supracrustal belts in the Baltic Shield. The Sodankylä
area in the central part of the belt represents a complex thrust duplex within a nappe overlying
Belomorian Archaean basement and autocthonous Luirojoki calc-silicate rocks. Here, an early D1
schistosity is axial planar to at least three coaxial generations of southward-verging, subhorizontal,
E–W-plunging D1 folds associated with major southwards thrusting.
D2 is represented by broad, map-scale,
upright, NE-trending folds in the south and crenulations in the north. Staurolite-grade metamorphism
represented by post-tectonic andalusite + staurolite + kyanite assemblages occurred after
D2 folding. Later D3 deformation was limited to local NW-trending folds and sinistral faults. The
internal nappe-like structure of the Central Lapland Greenstone belt suggests that it represents the
foreland of a large collisional complex cored by the Lapland Granulite belt.
The first find of diamond on the Sredny and Rybachy Peninsulas in the north-eastern Baltic Shield
