Skip to Main Content
Book Chapter

3. Neoarchean intracontinental areas of sedimentation, magmatism, and high-temperature metamorphism (hot regions) in eastern Fennoscandia

By
Michael V. Mints
Michael V. Mints
Geological Institute, Russian Academy of Sciences (RAS), 7 Pyzhevsky Lane, Moscow, 119017, Russia
Search for other works by this author on:
Published:
May 01, 2015

Beginning ca. 2.76 Ga, evolution of the Kola-Karelia crust was related to the intracontinental high-temperature metamorphic (up to granulite facies) and magmatic events in combination with formation of the basins related to rifting and infilling with intracontinental volcanic and sedimentary sequences initiated by plume-type processes in the mantle. The geological events corresponding to intracontinental evolution were expressed not only in the formation of new rock associations, juvenile to a significant extent, but also in reworking of previously formed rocks. The age, content, and mode of geological activity are somewhat different in the Kola and the Karelian-Belomorian regions.

The Karelian-Belomorian region is oval in plan view. The long axis of this oval extends for 600–700 km in the meridional direction; its maximum width is 400–450 km. The southern part of this oval structure is cut off along the NW-trending boundary with the Paleoproterozoic Svecofennian accretionary orogen. The main constituents of the Karelian-Belomorian region are: epicontinental sequences of greenstone belts (Kostomuksha, Khedozero-Bolsheozero, Gimoly-Sukkozero, Jalonvaara) and paragneiss belts (Hattu, Nurmes); granulite-gneiss complexes and intrusive enderbite-charnockite series; sanukitoid-type granitoid intrusions and lamprophyre dikes, along with migmatization and emplacement of within-plate young granites; and local manifestations of granulite-facies metamorphism superposed on older rocks. Concentric spatial distribution of related geological units is characteristic of the Karelian-Belomorian region. The geometric pattern of the region can be satisfactorily explained assuming initial activity of a mantle plume ca. 2.76 Ga in the central part of the region. A peak of activity was related to the events that occurred ca. 2.74–2.70 Ga. The geochronological data show that a region of high-temperature processes expanded from its center (2.76–2.73 Ga) to the periphery (2.74–2.70 Ga). The concentric character of the tectonic structure was eventually formed as a result of these processes. Widespread high-temperature magmatism and metamorphism in combination with formation of synformal and linear sedimentary basins indicate the setting of anorogenic extension and vigorous influx of extracrustal heat, i.e., a large event related to a mantle plume.

In contrast to the Karelian-Belomorian hot region, the coeval Kola region of intracontinental manifestations of high-temperature metamorphism and magmatism is characterized by oval-block geometry. This area, confined to the central part of the Kola Peninsula, extends for 600 km in the northwestern direction, having a width of ~200 km. It is possible that this area extends further to the southeast beneath the platform cover. The main tectonic units are the intracontinental greenstone belts (Sør-Varanger, Titovka, Uraguba, Olenegorsk, Voche-Lambina, Kachalovka, Runijoki–Khikhnajarvi, and Strelna system) in the Inari-Kola microcontinent, the granulite-gneiss Central Kola complex, and the Keivy volcanotectonic paleodepression. Sanukitoid intrusions play a modest role. The Keivy volcanotectonic paleodepression is situated in the eastern Kola Peninsula. Rocks of this tectonic unit are peculiar, and many of them have no obvious analogs in the Fennoscandian Shield or elsewhere. The major Neoarchean amphibolite-gneiss association consists of calc-alkaline to subalkaline garnet-biotite and subalkaline-peralkaline aegirine-arfvedsonite gneisses, as well as biotite-amphibole and amphibole gneisses, amphibolites, and rheomorphic alkali granites. In the western part of the paleodepression, gneisses (metavolcanic rocks) are cut through by small Sakharjok and Kuljok nepheline syenite intrusions. Geochronological estimates characterize two outbursts of magmatic activity separated by a long gap. The early outburst corresponds to magmatic crystallization of calc-alkaline metavolcanic rocks at 2.90–2.87 Ga. The second vigorous outburst documented at 2.68–2.63 Ga corresponds to eruption of subalkaline and subalkaline-peralkaline volcanic rocks, emplacement of alkali and nepheline syenites, and crystallization of gabbro-anorthosite of the Tsaga-Acherjok complex. The duration of the main magmatic phase is ~50 m.y., whereas the preceding gap lasted for ~200 m.y. A model of a volcanotectonic depression largely filled with pyroclastic flows seems plausible to explain pre-metamorphic events. Such manifestations of volcanic activity are inherent to intracontinental domains and related to activity of mantle plumes; similar processes can also develop in the back extensional zone of active continental margins. The synchronism of felsic volcanism and emplacement of the typically intracontinental gabbro-anorthosites form a sound argument in favor of an intracontinental setting for the Keivy paleodepression. The geometry of the Kola region can be satisfactorily explained in terms of mantle-plume activity noted ca. 2.76 Ga in the marginal part of this region; a peak of activity in its central part is related to the events that happened ca. 2.68–2.63 Ga.

You do not currently have access to this article.

Figures & Tables

Contents

GSA Special Papers

East European Craton: Early Precambrian History and 3D Models of Deep Crustal Structure

Michael V. Mints
Michael V. Mints
Geological Institute, Russian Academy of Sciences (RAS), 7 Pyzhevsky Lane, Moscow, 119017, Russia
Search for other works by this author on:
Ksenia A. Dokukina
Ksenia A. Dokukina
Geological Institute, Russian Academy of Sciences (RAS), 7 Pyzhevsky Lane, Moscow, 119017, Russia, and Lomonosov Moscow State University, GSP-1, Leninskie Gory, Moscow, 119991, Russia
Search for other works by this author on:
Alexander N. Konilov
Alexander N. Konilov
Geological Institute, Russian Academy of Sciences (RAS), 7 Pyzhevsky Lane, Moscow, 119017, Russia, and Institute of Experimental Mineralogy, Russian Academy of Sciences (RAS), Chernogolovka, Moscow Region, 142432, Russia
Search for other works by this author on:
Irina B. Philippova
Irina B. Philippova
Geological Institute, Russian Academy of Sciences (RAS), 7 Pyzhevsky Lane, Moscow, 119017, Russia
Search for other works by this author on:
Valery L. Zlobin
Valery L. Zlobin
Geological Institute, Russian Academy of Sciences (RAS), 7 Pyzhevsky Lane, Moscow, 119017, Russia
Search for other works by this author on:
Pavel S. Babayants
Pavel S. Babayants
Aerogeophysica Inc., 38/A b.15, 2-nd Khutorskaya Str., Off. 201, Moscow, 127287, Russia
Search for other works by this author on:
Elena A. Belousova
Elena A. Belousova
GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia
Search for other works by this author on:
Yury I. Blokh
Yury I. Blokh
Aerogeophysica Inc., 38/A b.15, 2-nd Khutorskaya Str., Off. 201, Moscow, 127287, Russia
Search for other works by this author on:
Maria M. Bogina
Maria M. Bogina
Institute of Ore Geology, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences (RAS), 35 Staromonetny Lane, Moscow, 119017, Russia
Search for other works by this author on:
William A. Bush
William A. Bush
Aerogeophysica Inc., 38/A b.15, 2-nd Khutorskaya Str., Off. 201, Moscow, 127287, Russia
Search for other works by this author on:
Peter A. Dokukin
Peter A. Dokukin
Peoples' Friendship University of Russia, 6 Miklukho-Maklaya Str., Moscow, 117198, Russia
Search for other works by this author on:
Tatiana V. Kaulina
Tatiana V. Kaulina
Geological Institute, Kola Science Centre RAS, 14 Fersman Str., Apatity, Murmansk Region, 184209, Russia
Search for other works by this author on:
Lev M. Natapov
Lev M. Natapov
GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia
Search for other works by this author on:
Valentina B. Piip
Valentina B. Piip
Lomonosov Moscow State University, GSP-1, Leninskie Gory, Moscow, 119991, Russia
Search for other works by this author on:
Vladimir M. Stupak
Vladimir M. Stupak
Branch of the Open Stock Company ?All-Russian Scientific and Research Institute of Geophysical Exploration???Spetsgeofizika,? Settlement Povarovo, 12 Povarovka, Moscow Region, 141540, Russia
Search for other works by this author on:
Arsen K. Suleimanov
Arsen K. Suleimanov
Branch of the Open Stock Company ?All-Russian Scientific and Research Institute of Geophysical Exploration???Spetsgeofizika,? Settlement Povarovo, 12 Povarovka, Moscow Region, 141540, Russia
Search for other works by this author on:
Alexey A. Trusov
Alexey A. Trusov
Aerogeophysica Inc., 38/A b.15, 2-nd Khutorskaya Str., Off. 201, Moscow, 127287, Russia
Search for other works by this author on:
Konstantin V. Van
Konstantin V. Van
Institute of Experimental Mineralogy, Russian Academy of Sciences (RAS), Chernogolovka, Moscow Region, 142432, Russia
Search for other works by this author on:
Nadezhda G. Zamozhniaya
Nadezhda G. Zamozhniaya
Branch of the Open Stock Company ?All-Russian Scientific and Research Institute of Geophysical Exploration???Spetsgeofizika,? Settlement Povarovo, 12 Povarovka, Moscow Region, 141540, Russia
Search for other works by this author on:
Geological Society of America
Volume
510
ISBN print:
9780813725109
Publication date:
May 01, 2015

References

Related

Citing Books via

Related Articles
Related Book Content
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal