HETEROGENEOUS LITHOSPHERIC STRUCTURE OF THE FENNOSCANDIAN SHIELD: SEISMIC DATA

A generalization has been obtained based on the data for deep seismic studies on longitudinal DSS profiles (explosion seismology) and seismological evidence found for local and distant earthquakes (earthquake seismology) in the Fennoscandian Shield over the past 40 years. This provided an opportunity to obtaine quantitative data on the horizontal and vertical heterogeneities of the lithosphere. 3D seismological models were first constructed for the individual parts of the Fennoscandian Shield which show that the crystalline crust structure acquires a block hierarchy pattern, with no persistent seismic boundaries found within the entire shield. The upper crust is characterized by the local occurrence of both waveguides and high-velocity zones correlated with geological bodies. The structural plans of the velocity isolines of various deep sections were found to be inconsistent. It has been proved that major geotectonic provinces have a thick crust and that the Early Proterozoic volcanogenic belts are characterized by elevated velocities and a large crustal thickness. In the upper mantle of the Fennoscandian Shield there were identified the layers with anomalously high velocities. No robust evidence was found for a waveguide, which is sometimes related to the concept of the lithosphere.

1. Babel Working Group, 1993. Deep Seismic Reflection/Refraction Interpretation of Crustal Structure along Babel Profiles A and B in the Southern Baltic Sea. Geophysical Journal International 112 (3), 325–343. https://doi.org/10.1111/j.1365-246X.1993.tb01173.x.

2. Bank O.J., Bostock M.G., Ellis R.M., 1998. Lithospheric Mantle Structure beneath the Trans-Hudson Orogen and the Origin of Diamondiferous Kimberlites. Journal of Geophysical Research: Solid Earth 103 (B5), 10103–10114. https://doi.org/10.1029/97JB03746.

3. Egorkin A.V., 2001. The Structure of the Upper Mantle under the Daldyn-Altai Kimberlite Field According to Seismograms of Nuclear Explosions. Geology of Ore Deposits 43 (1), 24–37 (in Russian)

4. EUGENO-S Working Group, 1988. Crustal Structure and Tectonic Evolution of Transition between the Baltic Shield and the North Germen Caledonides (the EUGENO-S Project). Tectonophysics 150 (3), 253–348. https://doi.org/10.1016/0040-1951(88)90073-X.

5. Gaal G., Gorbaschev R., 1987. An Outline of the Precambrian Evolution of the Baltic Shield. Precambrian Research 35, 15–52. https://doi.org/10.1016/0301-9268(87)90044-1.

6. Geyko V.S., 2004. A General Theory of the Seismic Travel–Time Tomography Geophysical Journal 26 (2), 3–32 (in Russian)

7. Glebovitsky V.A., 1993. Tectonics and Regional Metamorphism of the Early Proterozoic in the Eastern Part of the Shield. Regional Geology and Metallogeny 1, 7–24 (in Russian)

8. Grad M., Luosto U., 1993. Seismic Models of the Crust of the Baltic Shield along the SVEKA Profile in Finland. Acta Geophysica Polonica 41, 177–195.

9. Guggisberg B., Kaminski W., Prodehl C., 1991. Crustal Structure of the Fennoscandian Shield: A Traveltime Interpretation of the Long-Range FENNOLORA Seismic Refraction Profile. Tectonophysics 195 (2–4), 105–137. https://doi.org/10.1016/0040-1951(91)90208-A.

10. Khain V.E., 1993. Evolution of Geological Settings in the History of the Earth. In: N.P. Laverov (Ed.), Evolution of Geological Processes in the History of the Earth. Proceedings of the April 23–24, 1991 Moscow Conference. Nauka, Moscow, p. 29–37 (in Russian)

11. Koistinen T., Stephens M.B., Bogatchev V., Nordgulen O., Wennerström M., Korhonen J., 2001. Geological Map of the Fennoscandian Shield. Scale 1:2000000. Geological Surveys of Finland, Norway and Sweden and the North-West Department of Natural Resources of Russia.

12. Korhonen J.V., Aaro S., All T., Elo S., Haller L.Ä., Kääriäinen J., Kulinich A., Skilbrei J.R., Solheim D., Säävuori H., Vaher R., Zhdanova L., Koistinen T., 2002а. Bouguer Anomaly Map of the Fennoscandian Shield 1:2000000. Geological Surveys of Finland, Norway and Sweden and Ministry of Natural Resources of Russian Federation.

13. Korhonen J.V., Aaro S., All T., Nevanlinnce H., Skilbrei J.R., Säävuori H., Vaher R., Zhdanova L., Koistinen T., 2002b. Magnetic Anomaly Map of the Fennoscandian Shield. Scale 1:2000000. Geological Surveys of Finland, Norway and Sweden and Ministry of Natural Resources of Russian Federation.

14. Luosto U., Flueh E.R., Lund C.-E., Working Group, 1989. The Crustal Structure along the POLAR Profile from Seismic Refraction Investigations. Tectonophysics 162 (1–2), 51–85. https://doi.org/10.1016/0040-1951(89)90356-9.

15. Mitrofanov F.P., Sharov N.V. (Eds), 1998. Seismological Model of the Lithosphere of Northern Europe: Barents Region. Vol. 1. Publishing House of KSC RAS, Apatity, 237 p. (in Russian)

16. Pearson D.G. 1999. The Age of Continental Roots. Lithos 48 (1–4), 171–194. https://doi.org/10.1016/S0024-4937(99)00026-2.

17. Pushcharovsky D.Yu., Pushcharovsky Yu.M., 2010. Geology of the Earth’s Mantle. GEOS, Moscow, 140 p. (in Russian)

18. Pushcharovsky D.Yu., Pushcharovsky Yu.M., 2016. New Insight into the Composition and the Structure of the Terrestrial Planet’s Deep Seated Zones. Moscow University Geology Bulletin 1, 3–9 (in Russian) https://doi.org/10.33623/0579-9406-2016-1-3-9.

19. Rundqvist D.V., Mitrofanov F.P., 1988. Precambrian Geology of the USSR. Nauka, Leningrad, 440 p. (in Russian)

20. Sandoval Castaño S., 2002. The Lithosphere-Asthenosphere System beneath Fennoscandia (Baltic Shield) by Body-Wave Tomography. PhD Thesis (Doctor of Natural Sciences). Swiss Federal Institute of Technology, Zurich, 191 p. https://doi.org/10.3929/ethz-a-004422214.

21. Schueller W., Morozov I.B., Smithson S.B., 1997. Crustal and Uppermost Mantle Velocity Structure of Northern Eurasia along Profile Quartz. Bulletin of the Seismological Society of America 87 (32), 414–426. DOI:10.1785/BSSA0870020414.

22. Sharov N.V., 1993. Lithosphere of the Baltic Shield from Seismic Data. KSC RAS Publishing House, Apatity, 145 p. (in Russian)

23. Sharov N.V., 2000. Evolution of Views Concerning Models of Crystalline Crust Structure in the Baltic Shield. Regional Geology and Metallogeny 10, 32–43 (in Russian)

24. Sharov N.V. (Ed.), 2004. Deep Structure and Seismicity of the Karelian Region and Its Margins. KarRC RAS, Petrozavodsk, 353 p. (in Russian)

25. Sharov N.V., 2017. Lithosphere of Northern Europe: Seismic Data. KarRC RAS, Petrozavodsk, 173 p. (in Russian)

26. Sharov N.V., 2020. Superdeep Drilling and Its Impact on the Seismic Models of the Fennoscandian Shield. In: T.B. Yanovskaya, A. Kosterov, N.Yu. Bobrov, A.V. Divin, A.K. Saraev, N.V. Zolotova (Eds), Problems of Geocosmos-2018. Proceedings of the XII International Conference and School. Springer, 253–261. https://doi.org/10.1007/978-3-030-21788-4_21.

27. Shcheglov A.D., Moskaleva V.N., Markovsky B.A., Kolbantsev L.R., Orlova M.P., Smolkin V.F., 1993. Magmatism and Metallogeny of Riftogenic Systems of the Eastern Part of the Baltic Shield. Nedra, Saint Petersburg, 244 p. (in Russian)

28. Shustova L.E., Rabinovich G.Ya., 2003. Seismometry and Gravimetry in the Study of the Dynamics of the Precambrian Lithosphere. In: Studies of the Lithosphere in the Works of Saint Petersburg Geophysicists (Development of Academician G.A. Gamburtsev’s ideas). VIRG-Rudgeofizika, Saint Petersburg, p. 170–176 (in Russian)

29. Simons F.J., Zielhuis A., Hilst R.V.D., 1999. The Deep Structure of the Australian Continent from Surface Wave Tomography. Lithos 48 (1–4), 17–43. https://doi.org/10.1016/S0024-4937(99)00041-9.

30. Tiira T., Janik T., Skrzynik T., Komminaho K., Heinonen A., Veikkolainen T., Väkevä S., Korja A., 2020. Full-Scale Crustal Interpretation of Kokkola–Kymi (KOKKY) Seismic Profile, Fennoscandian Shield. Pure and Applied Geophysics 177, 3775–3795. https://doi.org/10.1007/s00024-020-02459-3.

31. Tripolsky A.A., Sharov N.V., 2004. Structure of the Precambrian Shields of the Northern Hemisphere of the Earth Lithosphere by Seismic Data. KarRC RAS, Petrozavodsk, 159 p. (in Russian)

32. Tsvetkova T.A., Bugaenko I.V., Zaets L.N., 2015. Three-Dimensional P-Velocity Model of the Mantle of Fennoscandia. LAMBERT Academic Publishing, Saarbrucken, 138 p. (in Russian)

33. Tsvetkova T.A., Shumlyanskaya L.A., Bugaenko I.V., Zayets L.N., 2009. Seismic-Tomography of the East-European Platform: Three-Dimensional P-Velocity Model of the Mantle under Fennoscandia-I. Geophysical Journal 31 (1), 53–72 (in Russian)

34. Tsvetkova T.A., Shumlyanskaya L.A., Bugaenko I.V., Zayets L.N., 2010. Seismic-Tomography of the East-European Platform: Three-Dimensional P-Velocity Model of the Mantle under Fennoscandia-II. Geophysical Journal 32 (1), 60–77 (in Russian)

35. Vinnik L.P., Green R.W.E., Nicolaysen L.O., Kosarev G.L., Petersen N.V., 1996. Deep Seismic Structure of the Kaapvaal Craton. Tectonophysics 262 (1–4), 67–75. https://doi.org/10.1016/0040-1951(96)00012-1.

36. Windley B.F., 1992. Precambrian Europe. In: D. Blandell, R. Freeman, S. Mueller (Eds), A Continent Revealed. The European Geotraverse. Cambridge University Press, 139–152. https://doi.org/10.1017/CBO9780511608261.008.

37. Zhamaletdinov A.A., Petrishchev M.S., 2015. A Quasi-Three-Dimensional Model of Lithosphere Electrical Conductivity of the Fennoscandian Shield Based on the Results of the BEAR and FENICS Experiments. Doklady Earth Sciences 463, 751–756. https://doi.org/10.1134/S1028334X15070235.

38. Zielhuis A., Hilst R., 1996. Upper Mantle Shear Velocity beneath Eastern Australia from Inversion of Waverforms from SKIPPY Portable Arrays. Geophysical Journal International 127 (1), 1–16. https://doi.org/10.1111/j.1365-246X.1996.tb01530.x.

39. Zolotov E.E., Kostyuchenko S.L., Rakitov V.A., Kurilovich I.A., Mishenkina Z.R., Treusov A.V., Sharov N.V., 2000. Inhomogeneities of the Upper Mantle of the Baltic Shield According to Seismic Tomography Data. Exploration and Protection of Mineral Resources 2, 27–29 (in Russian)