Glaciolacustrine terrace in the Izborsko-Malskaya valley: structure, age and mechanism of formation

Using the Izborsko-Malskaya valley (Pskov region) as an example was considered the issues of the origin of glaciolacustrine terraces in overdeepened valleys widespread in the Late Valdai (Ostashkov, Weichselian) glaciations areas. Fragments of the one-levelled terrace in the northern part of the Izborsko-Malskaya valley, composed of fine-laminated sands, are adjacent to the lower parts of the valley slopes. This terrace could be determined as alluvial or kame terrace. Detail field and lab investigations allowed us to establish the formation of fine-laminated sands. They accumulated in the proglacial lake during the Izborsko-Malskayay valley’s deglaciation. Then the sandy thickness was divided by the water flow. The formation of the erosional incision should not be associated with the modern r. Obdekh. It tooks a more significant water flow then in the modern river. Perhaps the dissection of the primary glaciolacustrine surface and the initiation of an erosion cut in the bottom of the valley occurred during the proglacial lake discharge ~ 13.3 ka. The ice-dammed drainage happened rather quickly. That is why there is no variability in the composition and facies in the upper part of the glaciolacustrine deposits. Furthermore, the additional terraces are absent in the erosion incision. Thus, the surfaces of terrace fragments have an accumulative glaciolacustrine origin and their scarps - erosional genesis. The new data on the mechanism formation of terraces in the northwest of the East European Plain differ from current concepts. Along with the previously described mechanisms of glaciolacustrine terraces formation (abrasion activity of former proglacial lakes, gradual cutting of rivers, or the formation of slopes of glacial contact in kame terraces), one should bear in mind the possibility of cutting powerful water flows during catastrophic discharges of proglacial lakes. The investigation results indicate the necessity for detailed studies in valleys on the northwest of the East European Plain.

1. Błaszkiewicz M., Piotrowski J., Brauer A., Gierszewski P., Kordowski J., Kramkowski M., Lamparski P., Lorenz S., Noryśkiewicz A., Ott F., Słowiński M., Tyszkowski S. Climatic and morphological controls on diachronous postglacial lake and river valley evolution in the area of Last Glaciation, northern Poland. Quaternary Science Reviews. 2015. Vol. 109. P. 13–27.

2. Kordowski J. The role of blocks of dead ice in the deposition of late glacial sediments in a large valley: A case study from the Vistula river valley in the Grudziądz basin, north Poland. Geographia Polonica. 2013. Vol. 86. № 4. P. 341–361.

3. Flint R. F. Glacial and Pleistocene Geology. New York: John Wiley & Sons, 1964. 892 р.

4. Isachenkov V.A. Prilednikovye vodoemy Pskovskoi niziny. Istoriya ozer Severo-Zapada (Proglacial lakes of the Pskov lowland. History of lakes in the North-West). L.: Izd-vo Geogr. Society of the USSR (Publ.), 1967. P. 86–93. (in Russ.)

5. Malakhovskii D.B. and Bakanova I.P. Krupneishie rechnye doliny. Geomorfologiya i chetvertichnye otlozheniya Severo-Zapada evropeiskoi chasti SSSR (Leningradskaya, Pskovskaya i Novgorodskaya oblasti) (The largest river valleys. Geomorphology and Quaternary deposits of the North-West of the European part of the USSR (Leningrad, Pskov and Novgorod regions)). L.: Nauka LO (Publ.), 1969. P. 54–65. (in Russ.)

6. Liblik T. Jooni Piusaoru geomorfoloogiast. Eesti Geograafia Seltsi Aastaraamat 1964/1965. 1966. P. 34–55.

7. Hang T., Miidel A., and Pirrus R. Late Weichselian and Holocene water-level changes of Lake Peipsi, eastern Estonia. PACT (Rixensart). 1996. No. 50. P. 121–131.

8. Lake Peipsi. Geology. A. Miidel, A. Jaani, A. Miidel, and A. Raukas (Eds.). Tallinn: Sulemees (Publ.), 1999. 21 p.

9. Palmer A.P. and Lowe J.J. Dynamic landscape changes in Glen Roy and vicinity, west Highland Scotland, during the Younger Dryas and early Holocene: a synthesis. Proceedings of the Geologists’ Association. 2017. Vol. 128. P. 2–25.

10. Sissons J.B. The lateglacial lakes of Glens Roy, Spean and vicinity (Lochaber district, Scottish Highlands). Proceedings of the Geologists’ Association. 2017. Vol. 128. P. 32–41.

11. Kvasov D.D. Pozdnechetvertichnaya istoriya krupnykh ozer i vnutrennikh morei Vostochnoi Evropy (The Late Quaternary history of large lakes and inland seas of Eastern Europe). L.: Nauka LO (Publ.), 1975. 278 p. (in Russ.)

12. Isachenkov V.A. O proiskhozhdenii dolinoobraznykh ponizhenii poverkhnosti dochetvertichnykh porod SeveroZapada Russkoi ravniny (About the origin of valley-like depressions in the surface of pre-Quaternary rocks of the North-West of the Russian Plain). Vestnik Moskovskogo Universiteta. Seriya 5. Geografiya. 1981. No. 6. P. 46–50. (in Russ.)

13. Malakhovskii D.B. and Fedorov B.G. O genezise i vozraste pereuglublenii na severe Evropy. Vozrast i genezis pereuglublenii na shel’fakh i istoriya rechnykh dolin (About the genesis and age of deepening valleys in the north of Europe. Age and genesis of deepening valley on the shelves and the history of river valleys). M.: Nauka (Publ.), 1984. C. 134–140. (in Russ.)

14. Krotova-Putintseva A.Y. and Verbitskiy V.R. Preglacial geomorphology of the northern Baltic Lowland and the Valdai Hills, north-western Russia. Bulletin of the Geological Society of Finland. 2012. Vol. 84. P. 58–68. (in Russ.)

15. Karpukhina N.V., Bricheva S.S., Konstantinov E.A., Tatarnikov O.M., Makkaveev A.N., and Zakharov A.L. O proiskhozhdenii terras v pogrebennykh dolinakh na severo-zapade Vostochno-Evropeiskoi ravniny (The origin of terraces in buried valleys in the northwest of the east european plain). Russian Geology and Geophysics. 2021. Vol. 62. No. 2. Р. 238–253. (in Russ.)

16. Geologiya SSSR (Geology of the USSR). T. Ι. Leningradskaya, Pskovskaya i Novgorodskaya oblasti. Geologicheskoe opisanie (Vol. 1 Leningrad, Pskov and Novgorod regions. Geological description). A.V. Sidorenko (Ed.). Moscow: Nedra (Publ.), 1971. 505 p. (in Russ.)

17. Tatarnikov O.M. Rel’ef i paleogeografiya Pskovskoi oblasti (Relief and paleogeography of Pskov region). Pskov: PGPU (Publ.), 2007. 127 p. (in Russ.)

18. Apukhtin N.I. and Sammet E.Yu. Pskovskaya, Novgorodskaya, zapadnaya i yuzhnaya chasti Leningradskoi oblasti (Pskov, Novgorod, western and southern parts of the Leningrad Region). Geologiya chetvertichnykh otlozhenii Severo-Zapada Evropeiskoi chasti SSSR Leningrad: Nedra (Publ.), 1967. P. 111–160. (in Russ.)

19. Isachenkov V.A. O devonskoi kueste na territorii Pskovskoi oblasti (About the Devonian cuesta in the Pskov region). Scientific notes of Pskov State Pedagogical Institute. 1969. No. 22. P. 3–10. (in Russ.)

20. Lesnenko V.K. O proyavlenii karsta na territorii Pechorskogo raiona Pskovskoi oblasti (About karst processes on the territory of the Pechora district of the Pskov region). Mat-ly 10 nauch. konf. Vol. 6. Pskov: PGPI (Publ.), 1968. P. 3–10. (in Russ.)

21. Tatarnikov O.M., Lesnenko V.K., and Mikhailov I.I. O sokhrannosti fragmenta devonskoi kuesty na territorii Pskovskoi oblasti (On the preservation of a fragment of the Devonian cuesta on the territory of the Pskov region). Geomorfologiya (Geomorphology RAS). 1995. No. 4. P. 81–83. (in Russ.)

22. Tatarnikov O.M. Landshaftno-ekologicheskaya i inzhenerno-geologicheskaya kharakteristika territorii Truvorova gorodishcha (Landscape-ecological and engineering-geological characteristics of the territory of the Truvor Settlement). Vestnik Pskovskogo Gosudarstvennogo universiteta. Seriya: Sotsial’no-gumanitarnye i psikhologo-pedagogicheskie nauki. 2013. № 2. P. 115– 123. (in Russ.)

23. Eyles N., Eyles C.H., and Miall A.D. Lithofacies types and vertical profile models; an alternative approach to the description and environmental interpretation of glacial diamict sequences. Sedimentology. 1983. Vol. 30. P. 393–410.

24. Baturin V.P. Petrograficheskii analiz geologicheskogo proshlogo po terrigennym komponentam (Petrographic analysis of the geological past by terrigenous components). M.–L.: Izd-vo i 2-ya tip. Izd-va Akad. nauk SSSR (Publ.), 1947. 338 p. (in Russ.)

25. Kurbanov R.N., Yanina T.A., Myurrei E.S., Semikolennykh D.V., Svistunov M.I., and Shtyrkova E.I. Vozrast karangatskoi transgressii (pozdnii pleistotsen) Chernogo morya (The age of the karangatian (Late Pleistocene) transgression of the Black Sea). Vestnik Moskovskogo universiteta. Seriya 5. Geografiya. 2019. No. 6. P. 29–38. (in Russ.)

26. Möller P. and Murray A.S. Drumlinised glaciofluvial and glaciolacustrine sediments on the Småland peneplain, South Sweden – new information on the growth and decay history of the Fennoscandian Ice Sheets during MIS3. Quaternary Science Reviews. 2015. Vol. 122. P. 1–29.

27. Murray A.S., Marten R., Johnston A., and Martin P. Analysis for naturally occurring radionu-clides at environmental concentrations by gamma spectrometry. Journal of Radioanalytical and Nuclear Chemistry. 1987. Vol. 115. Issue 2. P. 263–288.

28. Konstantinov E.A. and Eremenko E.A. Znachenie metoda lazernoi difraktsionnoi granulometrii pri izuchenii lessov (na primere razreza Melekino, Severnoe Priazov’e) (The value of the method of laser diffraction granulometry in the study of loess (on the example of the Melekino section, Northern Azov region)). Otechestvennaya geologiya. 2012. No. 3. P. 47–54. (in Russ.)

29. Karpukhina N.V. Osobennosti degradatsii ostashkovskogo lednikovogo pokrova v predelakh Chudsko-Pskovskoi nizmennosti (Characteristic features of the Ostashkov ice sheet degradation within Chudsko-Pskovskaya lowland). Geomorfologiya (Geomorphology RAS). 2013. No. 4. P. 38–47 (in Russ.)

30. Kalm V. Ice-flow pattern and extent of the last Scandinavian Ice Sheet southeast of the Baltic Sea. Quaternary Science Reviews. 2012. No. 44. P. 51–59.

31. Encyclopedia of Snow, Ice and Glaciers. Springer, 2011. 463 p.

32. Jørgensen F. and Sandersen P. Buried and open tunnel valleys in Denmark – erosion beneath multiple ice sheets. Quaternary Science Reviews. 2006. No. 25. P. 1339–1363.

33. Raukas A. Application of OSL and 10Be techniques to the establishment of deglaciation chronology in Estonia. Proceedings of the Estonian Academy of Sciences: Geology. 2004. Vol. 53. P. 267–287.

34. Alexanderson H. and Murray A. Problems and potential of OSL dating Weichselian and Holocene sediment in Sweden. Quaternary Science Reviews. 2009. No. 44. P. 37–50.

35. Raukas A.V. and Ryakhni E.E. O geologicheskom razvitii vpadiny i basseina Chudskogo i Pskovskogo ozer (On the geological development of the kettle and the Peipsi and Pskov lakes). Izv. AN ESSR. 1969. No. 2. P. 113–127. (in Russ.)

36. Rosentau A., Hang T., and Miidel A. Simulation of the shorelines of glacial Lake Peipsi in Eastern Estonia during the Late Weichselian. Geological Quarterly. 2004. Vol. 48. P. 299–307.

37. Miidel A., Hang T., Pirrus R., and Liiva A. On the development of the southern part of Lake Peipsi in the Holocene. Proc. Estonian Acad. Sci. Geol. 1995. Vol. 44. No. 1. P. 33–44.

38. Hang T., Kalm V., Kihno K., and Milkevičius M. Pollen, diatom and plant macrofossil assemblages indicate a low water level phase of Lake Peipsi at the beginning of the Holocene. Hydrobiologia. 2008. Vol. 599. P. 13–21.

39. Lisitsina G.N. Voprosy paleogeografii pozdnelednikovogo vremeni na territorii Severo-Zapada evropeiskoi chasti SSSR. Lednikovyi period na territorii evropeiskoi chasti SSSR i Sibiri (Issues of paleogeography of the Late Ice Age on the territory of the North-West of the European part of the USSR. Ice Age on the territory of the European part of the USSR and Siberia). M.: Izd-vo Moskovskogo universiteta (Publ.), 1959. P. 13–38. (in Russ.)