Synthesis of petrological, geochemical, and isotopic data on volcanic rocks and a related suite of xenoliths in the De Long Islands in the eastern sector of the Arctic basin is presented with the aim of reproducing the geochemical nature of the mantle sources of basaltic magmatism and its geodynamic environment in the continental shelf of the Laptev Sea, southeast of its intersection with the southern termination of the Gakkel Ridge. The main tool of this research was the comparative analysis of the isotopic characteristics of magmatic products on islands of this archipelago situated at different distances from the oceanic margin of the shelf. The reconstructed magmatic evolution at De Long Islands implies its close relations with the activity of a plume mantle source that occurred beneath the continental shelf of the Laptev Sea and was responsible for pulses of magmatic activity in this area of the eastern sector of the Arctic over the past 124nbsp;m.y. The volcanic activity at De Long Islands is determined to have become systematically younger from the offshore boundary of the continental shelf in the Laptev Sea Bennett Island inward the shelf Zhokhov Islands and farther southeastward Vil'kitskii Island.
intraplate magmatism, continental margin, Gakkel Ridge, Laptev Sea, basaltic magmatism.
1. Aoki, Materials Science of the Earth's Interior, edited by I. Sunagawa, 1984.
2. Backlund, Med. Acad. Abo, Geol.-Mineral. Inst., v. 1, 1920.
3. Barrat, Geochim. Cosmochim. Acta, v. 57, 1993., doi:https://doi.org/10.1016/0016-70379390570-M
4. Barrat, Earth Planet. Sci. Lett., v. 101, 1990., doi:https://doi.org/10.1016/0012-821X9090156-R
5. Bogdanovskii, Geokhimiya, v. 1, 1992.
6. Bogdanovskii, Dokl. Russ. Akad. Nauk., v. 330, 1993.
7. Coombs, J. Petrol., v. 10, 1969.
8. Dick, Nature, 2003.
9. Dosso, Earth Planet. Sci. Lett., v. 170, 1999.
10. Dubinin, Oceanic riftogenesis, 2001.
11. Eissen, J. Petrol., v. 30, 1989.
12. Fedorov, School on the Geochemistry of Magmatic Rocks, 2002.
13. Frey, Geochim. Cosmochim. Acta, v. 38, 1974., doi:https://doi.org/10.1016/0016-70377490003-9
14. Gakkel, Science and Exploring of the Arctic, 1957.
15. Geology..., Geology of the USSR, vol. IX, 1984.
16. Geology..., Geology of the USSR, Islands of the Soviet Arctic, vol. XXVI, 1970.
17. Grachev, Fiz. Zemli, v. 9, 1999.
18. Hellebrand, Chem. Geol., v. 182, 2002., doi:https://doi.org/10.1016/S0009-25410100291-1
19. Hofmann, Treatise on Geochemistry, vol. 2, 2003.
20. Ionov, Magmatic Rocks, Ultramafic Rocks, 1988.
21. Ionov, Doklady AN SSSR, v. 301, 1988.
22. Irving, Am. J. Sci., v. 280-A, 1980.
23. Jackson, J. Petrol., v. 11, 1970.
24. Kovalenko, Geokhimiya, v. 9, 1990.
25. Le Maitre, Classification of Igneous Rocks and Glossary of Terms, Part I, Recommendations of the International Union of Geological Sciences Subcommission on the Systematics of Igneous Rocks, 1989.
26. Lindsley, J. Geophys. Res., v. 88A, 1983.
27. Mercier, Tectonophysics, v. 70, 1980., doi:https://doi.org/10.1016/0040-19518090019-0
28. Michael, Nature, v. 423, 2003., doi:https://doi.org/10.1038/nature01704
29. Mori, J. Geol., v. 86, 1978.
30. Naryshkin, The Results of Investigations Within the Scope of International Geophysical Projects, 1987.
31. O'Neill, J. Petrol., v. 28, 1987.
32. Piskarev, Geology and Geophysics of Mid-Oceanic Ridges, Trans. of S. P. Mashchenkov workshop of the Russian branch of the InterRidge international project, 2001.
33. Ringwood, Composition and Petrology of the Earth's Mantle, 1975.
34. Sachtleben, Contrib. Mineral. Petrol, v. 78, 1981., doi:https://doi.org/10.1007/BF00373777
35. Saggerson, J. Petrol., v. 5, 1964.
36. Savostin, Doklady AN SSSR, v. 302, 1988.
37. Schilling, Science, v. 165, 1969., doi:https://doi.org/10.1126/science.165.3900.1357
38. Segev, Tectonophysics, v. 325, 2000., doi:https://doi.org/10.1016/S0040-19510000122-0
39. Sharkov, Int. symposium on mantle plumes and metallogeny, 2002.
40. Silantyev, Int. symposium on mantle plumes and metallogeny, 2002.
41. Silantyev, Geokhimiya, v. 2, 1991.
42. Sun, Magmatism in Ocean Basins. Geol. Soc. Spec. Publ. London, vol. 42, edited by A. D. Saunders and M. J. Norry, 1989.
43. Vaganov, Thermobarometry of Mafic Mineral Assemblages, 1988.
44. Vol'nov, Trans. Inst. Geol. Arktiki, Antarktiki, Akad. Nauk USSR, v. 123, 1961.
45. Vol'nov, Geology of the USSR, Islands of the Soviet Arctic, vol. XXVI, 1970.
46. Wass, Am. J. Sci., v. 280-A, 1980.
47. Wells, Contrib. Mineral. Petrol., v. 62, 1977., doi:https://doi.org/10.1007/BF00372872
48. Zhuravlev, Geokhimiya, v. 7, 1991.
49. Zindler, Ann. Rev. Earth Planet. Sci., v. 14, 1986.
