Scientific publications

The Archean rock record of the Kola region consists of several stages: (1) Formation of granitoid and TTG complexes and their reworking (~2.9–2.76 Ga). (2) Development of greenstone belts and their reworking: Kolmozero–Voron’ya Ura-Guba, 2.83–2.79 Ga; Olenegorsk, 2.81–2.76 Ga (simultaneously with TTG rocks in the northern Belomorian Province, 2.83–2.76 Ga); Voche-Lambina, ~2.72 Ga. (3) Post-orogenic stage in the Keivy Terrane: acid volcanics, alkaline granites (all A-type), and anorthosites, 2.68–2.66 Ga. Archean Belomorian eclogites remain disputable. The Paleoproterozoic history of this region exemplifies two most significant events of the Paleoproterozoic era in Earth’s history: continental rifting (2.5–2.0 Ga, development of large igneous provinces and the Pechenga–Imandra-Varzuga paleorift with short magmatic pulses) and growth of juvenile crust in orogenic belts (2.0–1.8 Ga). Paleoproterozoic juvenile crust was formed in the core of the Lapland-Kola collisional mixed-hot orogen. Its history consists of the opening of an oceanic Red Sea type basin (2.0–1.97 Ga), subduction and crustal growth (1.98–1.92 Ga), collision (1.93–1.91 Ga and 1.86 Ga, later local thrusting or orocline development), rapid exhumation of the orogenic core (decompression began at 1.90 Ga), and slow exhumation of the southwestern foreland. In addition to deep thrusts in the orogenic core, the Keivy Terrane experienced the tectonics of the detached middle crust. Paleoproterozoic eclogites were formed at ~ 1.91 Ga and resulted from tectonic crustal thickening or subduction. These findings can broaden our horizons regarding the Neoarchean Kenorland supercontinent and the Paleoproterozoic Columbia supercontinent (Nuna, Nena).