gtcrustГеодинамика и тектонофизикаGeodynamics & Tectonophysics2078-502XInstitute of the Earth's crust of the Russian Academy of Sciences, Siberian Branch10.5800/GT-2023-14-4-0715gtcrust-1723Research ArticleТЕКТОНОФИЗИКАTECTONOPHYSICSКОМБИНИРОВАННАЯ МОДЕЛЬ ДИАПИРОВОГО И КОЛЛИЗИОННОГО МЕХАНИЗМА ФОРМИРОВАНИЯ ГРАНИТ-МИГМАТИТ-ГНЕЙСОВЫХ КУПОЛОВ СВЕКОФЕННСКОГО ПОЯСА В ПАЛЕОПРОТЕРОЗОЕA COMBINED MODEL OF THE DIAPIRIC AND COLLISIONAL FORMATION MECHANISM OF THE PALEOPROTEROZOIC GRANITE-MIGMATITE-GNEISS DOMES OF THE SVECOFENNIAN BELThttps://orcid.org/0000-0003-2760-0754ПолянскийО. П.PolyanskyO. P.

630090, Новосибирск, пр-т Академика Коптюга, 3

3 Academician Koptyug Ave, Novosibirsk 630090

pol@igm.nsc.ruhttps://orcid.org/0000-0002-6484-2042БалтыбаевШ. К.BaltybaevS. K.

199034, Санкт-Петербург, наб. Макарова, 2

2 Makarov Emb, Saint Petersburg, 199034

https://orcid.org/0000-0002-8726-3000БабичевА. В.BabichevA. V.

630090, Новосибирск, пр-т Академика Коптюга, 3

3 Academician Koptyug Ave, Novosibirsk 630090

Институт геологии и минералогии им. В.С. Соболева СО РАНРоссияSobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of SciencesRussian FederationИнститут геологии и геохронологии докембрия РАНРоссияInstitute of Precambrian Geology and Geochronology, Russian Academy of SciencesRussian Federation202317082023144715715Copyright © Полянский О.П., Балтыбаев Ш.К., Бабичев А.В., 20232023Полянский О.П., Балтыбаев Ш.К., Бабичев А.В.Polyansky O.P., Baltybaev S.K., Babichev A.V.Данная работа распространяется под лицензией Creative Commons Attribution 4.0.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.gt-crust.ru/jour/article/view/1723

Геологические примеры развития термальных купольных структур в Свекофеннском поясе демонстрируют связь между плутоническими и метаморфическими событиями и усиление метаморфизма к ядерным частям этих структур. Для таких геологических обстановок создана 2D модель с количественной оценкой температурного воздействия мантийных магм в основании коры и формирования диапировых ядер, окруженных высокотемпературными ареалами со степенью метаморфизма до гранулитовой фации. Моделирование показывает возможность плавления нижней коры в присутствии водного флюида под воздействием мантийных магм. После плавления происходит диапировый подъем частично расплавленных масс на более высокие уровни. Потребляемый водный флюид переходит в расплав, понижая его вязкость и плотность. Высота подъема высокотемпературных ядер определяется глубиной перехода от вязкой к упругопластической реологии вещества коры. На более высокие уровни эти массы поднимаются в частично расплавленном состоянии в процессе надвигообразования за счет «коллизионной» тектоники.

Geological examples of the development of thermal dome structures in the Svecofennian belt demonstrate the relationship between plutonic and metamorphic events and metamorphic strengthening towards the core parts of the structures. The corresponding 2D geological model has been created to make a quantitative assessment of the effect of mantle magmas temperature at the base of the crust and the formation of the diapiric cores surrounded by high-temperature areas with a degree of granulite facies metamorphism. Modeling shows that there is a possibility of melting of the lower crust in the presence of a water fluid under the influence of mantle magmas. After melting, there occurs an ascent of partially molten material towards the upper crustal levels. An absorbed aqueous fluid changes to hydrous melt, thus lowering its viscosity and density. The ascending height of high-temperature cores is determined by the depth of viscous-to-elastoplastic transition in the crustal matter rheology. These materials ascend to upper levels in a partially molten state in the process of overthrusting due to "collisional" tectonics.

Свекофеннский поястермальные куполачисленное моделированиегранулитынадвигдиапирыSvecofennian beltthermal domesnumeric modelinggranulitesthrustdiapiric structuresИсследование выполнено за счет гранта Российского научного фонда (проект № 23-27-00106).This work was supported by the Russian Science Foundation (grant 23-27-00106).ReferencesAndersson U.B., Larsson L., Wikström A., 1992. Charnockites, Pyroxene Granulites and Garnet-Cordierite Gneisses at a Boundary between Early Svecofennian Rocks and Småland-Värmland Granitoids, Karlskoga, Soutliem Sweden. Geologiska Föreningens i Stockholm Förhandlingar 114 (1), 1–15. https://doi.org/10.1080/11035899209453457.Andersson U.B., Larsson L., Wikström A., 1992. Charnockites, Pyroxene Granulites and Garnet-Cordierite Gneisses at a Boundary between Early Svecofennian Rocks and Småland-Värmland Granitoids, Karlskoga, Soutliem Sweden. Geologiska Föreningens i Stockholm Förhandlingar 114 (1), 1–15. https://doi.org/10.1080/11035899209453457.Baltybaev Sh.K., Glebovitskii V.A., Kozyreva I.V., Konopelko D.L., Levchenkov O.A., Sedova I.S., Shuldiner V.I., 2000. Geology and Petrology of the Svecofennides of the Ladoga Region. Saint Petersburg University Publishing House, Saint Petersburg, 200 p. (in Russian)Baltybaev Sh.K., Glebovitskii V.A., Kozyreva I.V., Konopelko D.L., Levchenkov O.A., Sedova I.S., Shuldiner V.I., 2000. Geology and Petrology of the Svecofennides of the Ladoga Region. Saint Petersburg University Publishing House, Saint Petersburg, 200 p. (in Russian)Балтыбаев Ш.К., Глебовицкий В.А., Козырева И.В., Конопелько Д.Л., Левченков О.А., Седова И.С., Шульдинер В.И. Геология и петрология свекофеннид Приладожья. СПб.: Изд-во СПбГУ, 2000. 200 с.].Baltybaev Sh.K., Glebovitskii V.A., Kozyreva I.V., Shul’diner V.I., 1996. The Meyeri Thrust: The Main Element of the Suture at the Boundary between the Karelian Craton and the Svecofennian Belt in the Ladoga Region of the Baltic Shield. Doklady Earth Sciences 348 (4), 581–584.Baltybaev Sh.K., Glebovitskii V.A., Kozyreva I.V., Shul’diner V.I., 1996. The Meyeri Thrust: The Main Element of the Suture at the Boundary between the Karelian Craton and the Svecofennian Belt in the Ladoga Region of the Baltic Shield. Doklady Earth Sciences 348 (4), 581–584.Baltybaev Sh.K., Levchenkov O.A., Berezhnaya N.G., Levskii L.K., Makeev A.F., Yakovleva S.Z., 2004. Age and Duration of Svecofennian Plutono-Metamorphic Activity in the Ladoga Area, Southeastern Baltic Shield. Petrology 12 (4), 330–347.Baltybaev Sh.K., Levchenkov O.A., Berezhnaya N.G., Levskii L.K., Makeev A.F., Yakovleva S.Z., 2004. Age and Duration of Svecofennian Plutono-Metamorphic Activity in the Ladoga Area, Southeastern Baltic Shield. Petrology 12 (4), 330–347.Baltybaev Sh.K., Levchenkov O.A., Levskii L.K., 2009. Svecofennian Belt of the Fennoscandia: Spatiotemporal Correlation of the Early Proterozoic Endogenous Processes. Nauka, Saint Petersburg, 276 p. (in Russian)Балтыбаев Ш.К., Левченков О.А., Левский Л.К. Свекофеннский пояс Фенноскандии: пространственно-временная корреляция раннепротерозойских эндогенных процессов. СПб.: Наука, 2009. 276 с.Baltybaev Sh.K., Levchenkov O.A., Levsky L.K., Eklund O., Kilpeläinen T., 2006. Two Metamorphic Stages in the Svecofennian Domain: Evidence from the Isotopic Geochronological Study of the Ladoga and Sulkava Metamorphic Complexes. Petrology 14, 268–283. https://doi.org/10.1134/S0869591106030039.Baltybaev Sh.K., Levchenkov O.A., Levsky L.K., Eklund O., Kilpeläinen T., 2006. Two Metamorphic Stages in the Svecofennian Domain: Evidence from the Isotopic Geochronological Study of the Ladoga and Sulkava Metamorphic Complexes. Petrology 14, 268–283. https://doi.org/10.1134/S0869591106030039.Chopin F., Korja A., Hölttä P., 2013. Tectonometamorphic Evolution of a Large Dome in the Svecofennian Paleoproterozoic Accretionnary Orogeny. In: Abstracts of the General Assembly of the European Geosciences Union (April 7–12, 2013, Vienna, Austria). Vol. 15. EGU, EGU2013-10231.Chopin F., Korja A., Hölttä P., 2013. Tectonometamorphic Evolution of a Large Dome in the Svecofennian Paleoproterozoic Accretionnary Orogeny. In: Abstracts of the General Assembly of the European Geosciences Union (April 7–12, 2013, Vienna, Austria). Vol. 15. EGU, EGU2013-10231.Ehlers C., Lindroos A., Selonen O., 1993. The Late Svecofennian Granite-Migmatite Zone of Southern Finland – A Belt of Transpressive Deformation and Granite Emplacement. Precambrian Research 64 (1–4), 295–309. https://doi.org/10.1016/0301-9268(93)90083-E.Ehlers C., Lindroos A., Selonen O., 1993. The Late Svecofennian Granite-Migmatite Zone of Southern Finland – A Belt of Transpressive Deformation and Granite Emplacement. Precambrian Research 64 (1–4), 295–309. https://doi.org/10.1016/0301-9268(93)90083-E.Hansen F.D., Carter N.L., 1982. Creep of Selected Crustal Rocks at 1000 MPa. Transactions of the American Geophysical Union 63, 437.Hansen F.D., Carter N.L., 1982. Creep of Selected Crustal Rocks at 1000 MPa. Transactions of the American Geophysical Union 63, 437.Haudenschild U., 1988. K-Ar Age Determination on Biotite and Muscovite in the Pihtipudas – Lisalmi and Joroinen – Sulkava Areas, Eastern Finland. Bulletin of the Geological Survey of Finland 343, 33–50.Haudenschild U., 1988. K-Ar Age Determination on Biotite and Muscovite in the Pihtipudas – Lisalmi and Joroinen – Sulkava Areas, Eastern Finland. Bulletin of the Geological Survey of Finland 343, 33–50.Hölttä P., 1988. Metamorphic Zones and the Evolution of Granulite Grade Metamorphism in the Early Proterozoic Pielavesi Area, Central Finland. Bulletin of the Geological Survey of Finland 344, 50 p.Hölttä P., 1988. Metamorphic Zones and the Evolution of Granulite Grade Metamorphism in the Early Proterozoic Pielavesi Area, Central Finland. Bulletin of the Geological Survey of Finland 344, 50 p.Huhma H., 1986. Sm-Nd, U-Pb and Pb-Pb Isotopic Evidence for the Origin of the Early Proterozoic Svecokarelian Crust in Finland. Bulletin of the Geological Survey of Finland 337, 52 p.Huhma H., 1986. Sm-Nd, U-Pb and Pb-Pb Isotopic Evidence for the Origin of the Early Proterozoic Svecokarelian Crust in Finland. Bulletin of the Geological Survey of Finland 337, 52 p.Johannes W., Holtz F., 1996. Petrogenesis and Experimental Petrology of Granitic Rocks. Springer, Berlin, Heidelberg, 335 p. https://doi.org/10.1007/978-3-642-61049-3.Johannes W., Holtz F., 1996. Petrogenesis and Experimental Petrology of Granitic Rocks. Springer, Berlin, Heidelberg, 335 p. https://doi.org/10.1007/978-3-642-61049-3.Johnson M.R.W., Harley S.L., 2012. Orogenesis: The Making of Mountains. Cambridge University Press, 388 p.Johnson M.R.W., Harley S.L., 2012. Orogenesis: The Making of Mountains. Cambridge University Press, 388 p.Kitsul V.I., 1963. Petrology of Carbonate Rocks of the Ladoga Formation. Publishing House of the USSR Academy of Science, Moscow, 171 p. (in Russian)Кицул В.И. Петрология карбонатных пород ладожской формации. М.: Изд-во АН СССР, 1963. 171 с.Kolodyazhny S.Yu., 2006. Structural and Kinematic Evolution of the South-Eastern Part of the Baltic Shield in the Paleoproterozoic. GEOS, Moscow, 332 p. (in Russian)Колодяжный С.Ю. Структурно-кинематическая эволюция юго-восточной части Балтийского щита в палеопротерозое. М.: ГЕОС, 2006. 332 с.Korja A., Heikkinen P.J., 2008. Seismic Images of Paleoproterozoic Microplate Boundaries in the Fennoscandian Shield. In: K.C. Condie, V. Pease (Eds), When Did Plate Tectonics Begin on Planet Earth? GSA, p. 229–248. http://doi.org/10.1130/2008.2440(11).Korja A., Heikkinen P.J., 2008. Seismic Images of Paleoproterozoic Microplate Boundaries in the Fennoscandian Shield. In: K.C. Condie, V. Pease (Eds), When Did Plate Tectonics Begin on Planet Earth? GSA, p. 229–248. http://doi.org/10.1130/2008.2440(11).Korobeynikov S.N., 2000. Non-Linear Deformation of Solid Bodies. Publishing House of SB RAS, Novosibirsk, 262 p. (in Russian)Коробейников С.Н. Нелинейное деформирование твердых тел. Новосибирск: Изд-во СО РАН, 2000. 262 с.Korobeynikov S.N., Reverdatto V.V., Polyanski O.P., Sverdlova V.G., Babichev A.V., 2009. Computer Simulation of Underthrusting and Subduction Due to Collision of Slabs. Numerical Analysis and Applications 2 (1), 58–73. https://doi.org/10.1134/S1995423909010066.Korobeynikov S.N., Reverdatto V.V., Polyanski O.P., Sverdlova V.G., Babichev A.V., 2009. Computer Simulation of Underthrusting and Subduction Due to Collision of Slabs. Numerical Analysis and Applications 2 (1), 58–73. https://doi.org/10.1134/S1995423909010066.Korsman K., 1977. Progressive Metamorphism of the Metapelites in the Rantasalmi-Sulkava Area, Southeastern Finland. Bulletin of the Geological Survey of Finland 290, 82 p.Korsman K., 1977. Progressive Metamorphism of the Metapelites in the Rantasalmi-Sulkava Area, Southeastern Finland. Bulletin of the Geological Survey of Finland 290, 82 p.Korsman K., Hölttä P., Hautala T., Wasenius P., 1984. Metamorphism as an Indicator of Evolution and Structure of Crust in Eastern Finland. Bulletin of the Geological Survey of Finland 328, 40 p.Korsman K., Hölttä P., Hautala T., Wasenius P., 1984. Metamorphism as an Indicator of Evolution and Structure of Crust in Eastern Finland. Bulletin of the Geological Survey of Finland 328, 40 p.Korsman K., Korja T., Pajunen M., Virransalo P., GGT/ SVEKA Working Group, 1999. The GGT/SVEKA Transect: Structure and Evolution of the Continental Crust in the Paleoproterozoic Svecofennian Orogen in Finland. International Geology Review 41 (4), 287–333. https://doi.org/10.1080/00206819909465144.Korsman K., Korja T., Pajunen M., Virransalo P., GGT/ SVEKA Working Group, 1999. The GGT/SVEKA Transect: Structure and Evolution of the Continental Crust in the Paleoproterozoic Svecofennian Orogen in Finland. International Geology Review 41 (4), 287–333. https://doi.org/10.1080/00206819909465144.Korsman K., Niemela R., Wasenius P., 1988. Multistage Evolution of the Proterozoic Crust in the Savo Schist Belt, Eastern Finland. Bulletin of the Geological Survey of Finland 343, 89–96.Korsman K., Niemela R., Wasenius P., 1988. Multistage Evolution of the Proterozoic Crust in the Savo Schist Belt, Eastern Finland. Bulletin of the Geological Survey of Finland 343, 89–96.Luosto U., Lanne E., Korhonen H., 1984. Deep Structure of the Earth’s Crust on the Sveka Profile in Central Finland. Annales Geophysicae 2 (5), 559–570.Luosto U., Lanne E., Korhonen H., 1984. Deep Structure of the Earth’s Crust on the Sveka Profile in Central Finland. Annales Geophysicae 2 (5), 559–570.Marakushev A.A., Ashworth J.R. (Eds), 1988. Migmatites. Mir, Moscow, 344 p. (in Russian)Мигматиты / Ред. А.А. Маракушев, Дж.Р. Эшуорт. М.: Мир, 1988. 344 с.].Mei S., Bai W., Hiraga T., Kohlstedt D.L., 2002. Influence of Melt on the Creep Behavior of Olivine-Basalt Aggregates under Hydrous Conditions. Earth and Planetary Science Letters 201 (3–4), 491–507. https://doi.org/10.1016/S0012-821X(02)00745-8.Mei S., Bai W., Hiraga T., Kohlstedt D.L., 2002. Influence of Melt on the Creep Behavior of Olivine-Basalt Aggregates under Hydrous Conditions. Earth and Planetary Science Letters 201 (3–4), 491–507. https://doi.org/10.1016/S0012-821X(02)00745-8.Mitrofanov F.P. (Ed.), 1985. Migmatization and Granitization in Various Thermodynamic Regimes. Nauka, Leningrad, 310 p. (in Russian)Мигматизация и гранитообразование в различных термодинамических режимах / Ред. Ф.П. Митрофанов. Л.: Наука, 1985. 310 с.].Nagaitsev Yu.V., 1974. Petrology of the Rocks from the Ladoga and Belomorye Metamorphic Complexes. Publishing House of Leningrad State University, Leningrad, 160 p. (in Russian)Нагайцев Ю.В. Петрология метаморфических пород ладожского и беломорского комплексов. Л.: Изд-во ЛГУ, 1974. 160 с.].Pajunen M. (Ed.), 1994. High Temperature – Low Pressure Metamorphism and Deep Crustal Structures. Meeting of IGCP Project 304 "Deep Crustal Processes" in Finland, September 16–20, 1994. Geological Survey of Finland, Espoo, 75 p.Pajunen M. (Ed.), 1994. High Temperature – Low Pressure Metamorphism and Deep Crustal Structures. Meeting of IGCP Project 304 "Deep Crustal Processes" in Finland, September 16–20, 1994. Geological Survey of Finland, Espoo, 75 p.Papunen H., 1986. Platinum-Group Elements in Svecokarelian Nickel-Copper Deposits, Finland. Economic Geology 81(5), 1236–1241. http://doi.org/10.2113/gsecongeo.81.5.1236.Papunen H., 1986. Platinum-Group Elements in Svecokarelian Nickel-Copper Deposits, Finland. Economic Geology 81(5), 1236–1241. http://doi.org/10.2113/gsecongeo.81.5.1236.Patchett J., Kouvo O., 1986. Origin of Continental Crust of 1.9–1.7 Ga Age: Nd Isotopes and U-Pb Zircon Ages in the Svecokarelian Terrain of South Finland. Contributions to Mineralogy and Petrology 92, 1–12. http://doi.org/10.1007/BF00373959.Patchett J., Kouvo O., 1986. Origin of Continental Crust of 1.9–1.7 Ga Age: Nd Isotopes and U-Pb Zircon Ages in the Svecokarelian Terrain of South Finland. Contributions to Mineralogy and Petrology 92, 1–12. http://doi.org/10.1007/BF00373959.Polyansky O.P., Babichev A.V., Reverdatto V.V., Korobeynikov S.N., 2012. Formation and Upwelling of Mantle Diapirs through the Cratonic Lithosphere: Numerical Thermomechanical Modeling. Petrology 20, 120–137. https://doi.org/10.1134/S086959111202004X.Polyansky O.P., Babichev A.V., Reverdatto V.V., Korobeynikov S.N., 2012. Formation and Upwelling of Mantle Diapirs through the Cratonic Lithosphere: Numerical Thermomechanical Modeling. Petrology 20, 120–137. https://doi.org/10.1134/S086959111202004X.Polyansky O.P., Kargopolov S.A., Babichev A.V., Reverdatto V.V., 2019. High-Grade Metamorphism and Anatexis in the Teletskoe–Chulyshman Belt (Gorny Altai): U–Pb Geochronology, Р-Т Estimates, and Thermal Tectonic Model. Russian Geology and Geophysics 60, 12, 1425–1443. https://doi.org/10.15372/RGG2019108.Polyansky O.P., Kargopolov S.A., Babichev A.V., Reverdatto V.V., 2019. High-Grade Metamorphism and Anatexis in the Teletskoe–Chulyshman Belt (Gorny Altai): U–Pb Geochronology, Р-Т Estimates, and Thermal Tectonic Model. Russian Geology and Geophysics 60, 12, 1425–1443. https://doi.org/10.15372/RGG2019108.Polyansky O.P., Korobeynikov S.N., Babichev A.V., Reverdatto V.V., Sverdlova V.G., 2014. Numerical Modeling of Mantle Diapirism as a Cause of Intracontinental Rifting. Izvestiya, Physics of the Solid Earth 50, 839–852. https://doi.org/10.1134/S1069351314060056.Polyansky O.P., Korobeynikov S.N., Babichev A.V., Reverdatto V.V., Sverdlova V.G., 2014. Numerical Modeling of Mantle Diapirism as a Cause of Intracontinental Rifting. Izvestiya, Physics of the Solid Earth 50, 839–852. https://doi.org/10.1134/S1069351314060056.Predovsky A.A., Petrov V.P., Belyaev O.A., 1967. Geochemistry of Ore Elements of the Precambrian Metamorphic Series (by the Example of the Northern Ladoga Area). Nauka, Leningrad, 139 p. (in Russian)Предовский А.А., Петров В.П., Беляев О.А. Геохимия рудных элементов метаморфических серий докембрия (на примере Северного Приладожья). Л.: Наука, 1967. 139 с.Prokoph A., Ernst R.E., Buchan K.L., 2004. Time-Series Analysis of Large Igneous Provinces: 3500 Ma to Present. The Journal of Geology 112 (1), 1–22. https://doi.org/10.1086/379689.Prokoph A., Ernst R.E., Buchan K.L., 2004. Time-Series Analysis of Large Igneous Provinces: 3500 Ma to Present. The Journal of Geology 112 (1), 1–22. https://doi.org/10.1086/379689.Quick J.E., Sinigoi S., Mayer A., 1994. Emplacement Dynamics of a Large Mafic Intrusion in the Lower Crust, Ivrea-Verbano Zone, Northern Italy. Journal of Geophysical Research: Solid Earth 99 (B11), 21559–21573. https://doi.org/10.1029/94JB00113.Quick J.E., Sinigoi S., Mayer A., 1994. Emplacement Dynamics of a Large Mafic Intrusion in the Lower Crust, Ivrea-Verbano Zone, Northern Italy. Journal of Geophysical Research: Solid Earth 99 (B11), 21559–21573. https://doi.org/10.1029/94JB00113.Shuldiner V.I., Baltibaev Sh.K., Kozyreva I.V., 1997. Metamorphic Evolution of Garnet-Bearing Granulites in the Western Ladoga Area. Petrology 5 (3), 223–245.Shuldiner V.I., Baltibaev Sh.K., Kozyreva I.V., 1997. Metamorphic Evolution of Garnet-Bearing Granulites in the Western Ladoga Area. Petrology 5 (3), 223–245.Sudovikov N.G., 1954. Tectonics, Metamorphism, Migmatization and Granitization of Rocks of the Ladoga Formation. In: Transactions of the Laboratory of Precambrian Geology. Iss. 4. Publishing House of the USSR Academy of Science, Moscow, Leningrad, 198 p. (in Russian)Судовиков Н.Г. Тектоника, метаморфизм, мигматизация и гранитизация пород ладожской формации // Труды лаборатории геологии докембрия. М.–Л.: Изд-во АН СССР, 1954. Вып. 4. 198 с.Sudovikov N.G., Glebovitskii V.A., Sergeev A.S., Petrov V.P., Kharitonov A.L., 1970. Geological Development of the Depth Zones in the Mobile Belts (Northern Ladoga Region). Nauka, Leningrad, 227 p. (in Russian)Судовиков Н.Г., Глебовицкий В.А., Сергеев А.С., Петров В.П., Харитонов А.Л. Геологическое развитие глубинных зон подвижных поясов (Северное Приладожье). Л.: Наука, 1970. 227 с.Vaasjoki M., Kontoniemi O., 1991. Isotopic Studies the Proterozoic Osikonmaki Gold Prospect at Rantasalmi, Shoutheastern Finland. Geological Survey of Finland. Special Paper 12, 53–57.Vaasjoki M., Kontoniemi O., 1991. Isotopic Studies the Proterozoic Osikonmaki Gold Prospect at Rantasalmi, Shoutheastern Finland. Geological Survey of Finland. Special Paper 12, 53–57.Vaasjoki M., Sakko M., 1988. The Evolution of the Raahe- Ladoga Zone in Finland: Isotopic Constrains. Bulletin of the Geological Survey of Finland 343, 7–32.Vaasjoki M., Sakko M., 1988. The Evolution of the Raahe- Ladoga Zone in Finland: Isotopic Constrains. Bulletin of the Geological Survey of Finland 343, 7–32.Väisänen M., Manttari I., Hölttä P., 2002. Svecofennian Magmatic and Metamorphic Evolution in Southwestern Finland as Revealed by U-Pb Zircon SIMS Geochronology. Precambrian Research 116 (1–2), 111–127. http://doi.org/10.1016/S0301-9268(02)00019-0.Väisänen M., Manttari I., Hölttä P., 2002. Svecofennian Magmatic and Metamorphic Evolution in Southwestern Finland as Revealed by U-Pb Zircon SIMS Geochronology. Precambrian Research 116 (1–2), 111–127. http://doi.org/10.1016/S0301-9268(02)00019-0.Veenhof R.P., Stel H., 1991. A Cleavage Triple Point and Its Meso-Scopic Structures: The Mustio Sink (Svecofennides of SW Finland). Precambrian Research 50 (3–4), 269–282. https://doi.org/10.1016/0301-9268(91)90025-6.Veenhof R.P., Stel H., 1991. A Cleavage Triple Point and Its Meso-Scopic Structures: The Mustio Sink (Svecofennides of SW Finland). Precambrian Research 50 (3–4), 269–282. https://doi.org/10.1016/0301-9268(91)90025-6.Velikoslavinskii D.A., 1972. Comparative Characteristics of the Moderate- and Low-Pressure Regional Metamorphism (on the Example of the North Baikal and North Ladoga Regions of the Development of Metamorphic Zonality). Nauka, Leningrad, 190 p. (in Russian)Великославинский Д.А. Сравнительная характеристика регионального метаморфизма умеренных и низких давлений (на примере Северо-Байкальской и Северо-Ладожской областей развития метаморфической зональности). Л.: Наука, 1972. 192 с.Великославинский Д.А. Сравнительная характеристика регионального метаморфизма умеренных и низких давлений (на примере Северо-Байкальской и Северо-Ладожской областей развития метаморфической зональности). Л.: Наука, 1972. 192 с.

The authors declare that there are no conflicts of interest present.