Two types of plagiogneiss have been distinguished among Archaean rocks of the KSDB. Their protoliths formed at P ge; 15kbar type A, garnet-amphibolite restite and 8 kbar type B, plagioclase-amphibole restite. The conditions under which these rocks originated appear to be similar to those recognised for the Garsj\o\ plagiogneiss, which is located in the Svanvik-Lotta segment of the Kola-Norwegian block, and probably belongs to the upper part of the Bj\o rnevatn greenstone belt. Protoliths of certain Garsj\o\ gneisses type C were generated by partial melting of a metabasic source rock enriched in light rare earth and other incompatible elements e.g. Sr, and corresponding in composition to TH2 basalt. In contrast to the Garsj\o\ gneiss, the tonalite-trondhjemite rocks of the KSDB were derived from relatively poor-differentiated metabasic rocks which are characterised by lower La/Yb ratios and lower Sr content, and are compatible to TH1 tholeiite. On the Kola Peninsula, homologues of the tonalite-trondhjemite rocks of the KSDB are likely to be found within the Olenegorsk greenstone belt in the central part of the Kola Peninsula. It is concluded that the formation of tonalite-trondhjemite rocks has considerable influence on the composition of the lower crust of the region.
Archaean rocks, Kola Superdeep Borehole, types of plagiogneiss.
1. Balashov, Archaean Complex in the SG-3 Section, Yu. N. Yakovlev and V. S. Lanev eds., 1991.
2. Balashov, Correlation of Precambrian Formations of the Kola-Karelian Region and Finland, Balagansky V. V. and Mitrofanov P. P. eds., 1992.
3. Batiev, Endogenic Regimes and Evolution of the Magmatism in Early Precambrian, 1991.
4. Beard, J. Petrol, v. 32, 1991.
5. Belkov, Precambrian Magmatic Formation of Northeastern Baltic Shield, 1985.
6. Bibikova, Doklady RAN, v. 332, no. 3, 1993.
7. Braun, Abstracts of 1st International Barents Symposium, 1993.
8. Bridgwater, Svekalapko WS, Lammi, Abstracts, 28-30. 11. 1996, 1996.
9. Chen, Kola Superdeep, Research Results and Experience, Orlov V. P. and Laverov N. P. eds., 1998.
10. Condie, Archaean Greenstone Belts, 1981.
11. Dobrzhinetskaya, Nor. Geol. Unders., Special Publ, 1995.
12. Evensen, Geochim., Cosmochim. Acta, v. 42, no. 8, 1978., doi:https://doi.org/10.1016/0016-70377890114-X
13. Feng, Canadian J. Earth Sci., v. 29, 1992.
14. Glukhovsky, Geotektonika, no. 6, 1996.
15. Hain, Proceedings of Moscow State Univ., series 4, Geologiya, no. 6, 1993.
16. Inaugural Meeting..., Episodes, v. 21, no. 4, 1998.
17. Juve, Nor. Geol. Unders., Special Publ., 1995.
18. Kozlovsky, Kola Superdeep. A Study of Deep Structure of the Continental Crust with the Help of Drilling the Kola Superdeep Borehole, 1984.
19. Kremenetsky, Geochemistry of Deep Rocks, 1986.
20. Kremenetsky, Geologic-geochemical Methods to Forecast Deep-seated Mineral Deposits, 1990.
21. Kroner, Tectonophys., v. 187, 1991., doi:https://doi.org/10.1016/0040-19519190478-B
22. Levchenkov, Nor. Geol. Unders. Special. Publ., v. 7, 1995.
23. Lobach-Zhuchenko, Natural Associations of Archaean Grey Gneisses Geology and Petrology, 1984.
24. Martin, J. Petrol, v. 28, 1987.
25. Mints, Early Precambrian of the Northeastern Baltic Shield: Palaeogeodynamics, Structure and Evolution of Continental Crust, 1996.
26. Mitrofanov, Geology of the Kola Peninsula, 1995.
27. Mitrofanov, Seismogeological Model of the Lithosphere of Northern Europe: Barents Region, Part 1, 1998.
28. Mitrofanov, Homologues of rocks in the Kola Superdeep Borehole KSDB and on the surface, 1998.
29. O'Konnor, US Geol. Surv. Prof. Pap., no. 525-B, 1965.
30. Orlov, Kola Superdeep, Research Results and Experience, 1998.
31. Pearse, Volcanic Rocks, Contribution to Mineralogy and Petrology, v. 69, 1979., doi:https://doi.org/10.1007/BF00375192
32. Pushkarev, Geochronometric Benchmarks of Precambrian Kola Peninsula, 1978.
33. Raase, Contr. Miner., Petrol, v. 44, no. 3, 1974.
34. Rapp, Mineral. Mag., v. 58A, 1994., doi:https://doi.org/10.1180/minmag.1994.58A.2.132
35. Rapp, J. Petrol., v. 36, 1995.
36. Rapp, Precambr. Res., v. 51, 1991., doi:https://doi.org/10.1016/0301-92689190092-O
37. Ronov, Chemical Structure of the Earth's Crust and the Geochemical Balance of Major Elements, 1990.
38. Rudnick, Reviews of Geophysics, v. 33, no. 3, 1995., doi:https://doi.org/10.1029/95RG01302
39. Sen, Contrib. Mineral, Petrol, v. 117, 1994., doi:https://doi.org/10.1007/BF00307273
40. Siedlecka, Nor. Geol. Unders., Bull., v. 403, 1985.
41. Sun, Geol. Soc. London Spec. Publ., v. 42, 1989.
42. Taylor, The Continental Crust: its Composition and Evolution, 1985.
43. Timmerman, Precambr. Research, v. 72, 1995.
44. Turkina, Mineral Mag., 1998., doi:https://doi.org/10.1180/minmag.1998.62A.3.145
45. Van der Laan, J. Geology, v. 100, 1992.
46. Vetrin, Natural Associations of Archaean Grey Gneisses Geology and Petrology, 1984.
47. Vetrin, Archaean Complex in the SG-3 Section, Yu. N. Yakovlev and V. S. Lanev eds., 1991.
48. Vielzeuf, Contrib. Mineral., Petrol., v. 117, 1994., doi:https://doi.org/10.1007/BF00307272
49. Winther, Chem. Geol., v. 127, 1996., doi:https://doi.org/10.1016/0009-25419500087-9
50. Yakovlev, Archaean Complex in the SG-3 Section, 1991.
51. Zagorodny, Tectonics of the Early Precambrian Kola Peninsula, 1983.
52. Zharikov, Doklady RAN, v. 342, no. 2, 1995.
