Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 46626 ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ The nature of Late Cenozoic volcanism in the Udokan Range, northwestern segment of the Baikal Rift Zone The nature of Late Cenozoic volcanism in the Udokan Range, northwestern segment of the Baikal Rift Zone Grachev A F Grachev A F Schmidt Institute of Physics of the Earth, Russian Academy of Sciences ru Schmidt Institute of Physics of the Earth, Russian Academy of Sciences ru 17 1 1 9 29 10 2021 https://rjes.ru/en/nauka/article/46626/view

Newly obtained major-component, trace-element, and rare-earth element (REE) analyses are used to gain insight into the nature of Late Cenozoic volcanism in the Udokan Range. The composition of the lavas is analyzed in each lava flow and it is demonstrated that the rocks define a bimodal differentiated series with a Daly gap. The absence of andesite is seen not only in the summarizing diagrams but also in individual vertical sections of the volcanic rocks. The petrochemical specifics of volcanics in the Udokan Range involves broad variations in the TiO$_2$ concentrations: from 0.22 to 4.41 wt %. The REE patterns of the volcanics show a trend analogous to that of oceanic islands basalts (OIB). The compositional specifics of the rocks suggest that the basalt-trachyte series was derived from a single mantle source related to a mantle plume.

Newly obtained major-component, trace-element, and rare-earth element (REE) analyses are used to gain insight into the nature of Late Cenozoic volcanism in the Udokan Range. The composition of the lavas is analyzed in each lava flow and it is demonstrated that the rocks define a bimodal differentiated series with a Daly gap. The absence of andesite is seen not only in the summarizing diagrams but also in individual vertical sections of the volcanic rocks. The petrochemical specifics of volcanics in the Udokan Range involves broad variations in the TiO$_2$ concentrations: from 0.22 to 4.41 wt %. The REE patterns of the volcanics show a trend analogous to that of oceanic islands basalts (OIB). The compositional specifics of the rocks suggest that the basalt-trachyte series was derived from a single mantle source related to a mantle plume.

 Volcanism Daly gap mantle plume Baikal Rift Udokan Range Volcanism Daly gap mantle plume Baikal Rift Udokan Range

Amirkhanov, Kh. I., Batyrmurzaev, A. S., Gargantsev, I. O., Omarova, M. R., Gadzhiev, S. Z. Age of volcanic basalts in the Udokan depression, Baikal Rift Zone, and the area of Lake Khubsugul, Mongolia, // Dokl. AN SSSR, 1985. - v. 285 - no. 2 - p. 411. Amirkhanov, Kh. I., Batyrmurzaev, A. S., Gargantsev, I. O., Omarova, M. R., Gadzhiev, S. Z. Age of volcanic basalts in the Udokan depression, Baikal Rift Zone, and the area of Lake Khubsugul, Mongolia, // Dokl. AN SSSR, 1985. - v. 285 - no. 2 - p. 411. Bagdasaryan, G. N., et al. Newly obtained data on the isotopic age and chemical composition of volcanic rocks in the Baikal Rift Zone, // Geokhimiya, 1981. - no. 3 - p. 342. Bagdasaryan, G. N., et al. Newly obtained data on the isotopic age and chemical composition of volcanic rocks in the Baikal Rift Zone, // Geokhimiya, 1981. - no. 3 - p. 342. Baker, I. Intermediate oceanic volcanic rocks and the ``Daly gap'', // Earth Planet. Sci. Lett., 1968. - v. 4 - p. 103. Baker, I. Intermediate oceanic volcanic rocks and the ``Daly gap'', // Earth Planet. Sci. Lett., 1968. - v. 4 - p. 103. Baker, P. E., Gass, I. G., Harris, P. G., Le Maitre, R. W. The volcanological report of the Royal Society expedition to Tristan Da Cunha, 1962, // Phil. Trans. Roy. Soc. London. Series A, 1964. - v. 256 - no. 1075 - p. 439. Baker, P. E., Gass, I. G., Harris, P. G., Le Maitre, R. W. The volcanological report of the Royal Society expedition to Tristan Da Cunha, 1962, // Phil. Trans. Roy. Soc. London. Series A, 1964. - v. 256 - no. 1075 - p. 439. Cox, K. G., Bell, J. D., Pankhurst, R. J. The Interpretation of Igneous Rocks - London: Chapman [ampersand] Hall., 1979. Cox, K. G., Bell, J. D., Pankhurst, R. J. The Interpretation of Igneous Rocks - London: Chapman [ampersand] Hall., 1979. Gibson, S. A., Thompson, R. N., Dickin, A. P., Leonardos, O. H. High-Ti and Low-Ti mafic potassic magmas: Key to plume-lithosphere interactions and continental flood-basalts genesis, // Earth Planet. Sci. Lett., 1995. - v. 136 - p. 149. Gibson, S. A., Thompson, R. N., Dickin, A. P., Leonardos, O. H. High-Ti and Low-Ti mafic potassic magmas: Key to plume-lithosphere interactions and continental flood-basalts genesis, // Earth Planet. Sci. Lett., 1995. - v. 136 - p. 149. Grachev, A. F. Rift Zones of the Earth - Leningrad: Nedra., 1977. Grachev, A. F. Rift Zones of the Earth - Leningrad: Nedra., 1977. Grachev, A. F. Khamar Daban, a hotspot in the Baikal Rift: chemical geodynamic evidence, // Fizika Zemli, 1998. - no. 2 - p. 3. Grachev, A. F. Khamar Daban, a hotspot in the Baikal Rift: chemical geodynamic evidence, // Fizika Zemli, 1998. - no. 2 - p. 3. Grachev, A. F., Blyumshtein, E. I., Sokolova, E. P., Levykin, A. Lherzolite nodules in alkaline basalt from the Baikal Rift, // Dokl. AN SSSR, 1973. - v. 211 - no. 2 - p. 445. Grachev, A. F., Blyumshtein, E. I., Sokolova, E. P., Levykin, A. Lherzolite nodules in alkaline basalt from the Baikal Rift, // Dokl. AN SSSR, 1973. - v. 211 - no. 2 - p. 445. Drubetskoi, E. R., Grachev, A. F. Helium and argon isotopes in basanites and ultramafic nodules in the Baikal Rift Zone // Mantle Xenoliths and the Structure of the Lithosphere - Moscow: Nauka., 1987. - p. 54. Drubetskoi, E. R., Grachev, A. F. Helium and argon isotopes in basanites and ultramafic nodules in the Baikal Rift Zone // Mantle Xenoliths and the Structure of the Lithosphere - Moscow: Nauka., 1987. - p. 54. Harris, N. R. Isotopical, Geochemical and Geochronological Constraints on the Origin and Evolution of Cenozoic Volcanism, Baikal Rift Zone, Siberia - Boston: MIT., 1998. - 438 pp. Harris, N. R. Isotopical, Geochemical and Geochronological Constraints on the Origin and Evolution of Cenozoic Volcanism, Baikal Rift Zone, Siberia - Boston: MIT., 1998. - 438 pp. Johnson, J. S., Gibson, S. A., Thompson, R. N., Nowell, G. M. Volcanism in the Vitim volcanic field: geochemical evidence for a mantle plume beneath the Baikal rift zone, // Jour. Petrology, 2005. - v. 46 - p. 1309. Johnson, J. S., Gibson, S. A., Thompson, R. N., Nowell, G. M. Volcanism in the Vitim volcanic field: geochemical evidence for a mantle plume beneath the Baikal rift zone, // Jour. Petrology, 2005. - v. 46 - p. 1309. Kiselev, A. I., Medvedev, M. E., Golovko, G. A. Volcanism in the Baikal Rift Zone and Problems of Deep-Sitting Magma Generation - Novosibirsk: Nauka., 1979. - 197 pp. Kiselev, A. I., Medvedev, M. E., Golovko, G. A. Volcanism in the Baikal Rift Zone and Problems of Deep-Sitting Magma Generation - Novosibirsk: Nauka., 1979. - 197 pp. Mahoney, J. J., Coffin. M. F. (eds.) Large Igneous Provinces // Am. Geophys. Union Monograph 100 - W: AGU., 1997. - p. 1309. Mahoney, J. J., Coffin. M. F. (eds.) Large Igneous Provinces // Am. Geophys. Union Monograph 100 - W: AGU., 1997. - p. 1309. McDonough, W. F., Sun, S.-s. The composition of the Earth, // Chem. Geol., 1995. - v. 120 - p. 223. McDonough, W. F., Sun, S.-s. The composition of the Earth, // Chem. Geol., 1995. - v. 120 - p. 223. Muzis, A. I. Cenozoic rocks and modern tectonics in the Olekma-Vitim Highland - Moscow: IFZ RAS., 1970. Muzis, A. I. Cenozoic rocks and modern tectonics in the Olekma-Vitim Highland - Moscow: IFZ RAS., 1970. Mysen, B. O., Ryerson, F. J., Virgo, D. The structural role of phosphorus in silicate melts, // Am. Min., 1981. - v. 66 - p. 106. Mysen, B. O., Ryerson, F. J., Virgo, D. The structural role of phosphorus in silicate melts, // Am. Min., 1981. - v. 66 - p. 106. Polyakov, A. I., Bagdasaryan, G. P. On the age of young volcanic rocks in eastern Siberia and evolutionary tendencies of their composition, // Geokhimiya, 1986. - no. 3 - p. 311. Polyakov, A. I., Bagdasaryan, G. P. On the age of young volcanic rocks in eastern Siberia and evolutionary tendencies of their composition, // Geokhimiya, 1986. - no. 3 - p. 311. Rasskazov, S. V. Basaltoids of Udokan - Novosibirsk: Nauka., 1985. - 142 pp. Rasskazov, S. V. Basaltoids of Udokan - Novosibirsk: Nauka., 1985. - 142 pp. Rasskazov, S. V., et al. Geology and Geodynamics in the Late Cenozoic: Southern Siberia and Southeast Asia - Novosibirsk: Nauka., 2000. - 288 pp. Rasskazov, S. V., et al. Geology and Geodynamics in the Late Cenozoic: Southern Siberia and Southeast Asia - Novosibirsk: Nauka., 2000. - 288 pp. Ryerson, F. J., Hess, P. C. The role of P$_2$O$_5$ in silicate melts, // Geochim. Cosmochim. Acta, 1980. - v. 44 - p. 611. Ryerson, F. J., Hess, P. C. The role of P$_2$O$_5$ in silicate melts, // Geochim. Cosmochim. Acta, 1980. - v. 44 - p. 611. Solonenko, V. P. (ed.) Live Tectonics, Volcanoes, and Seismicity of the Stanovoi Highland - Moscow: Nauka., 1966. - 230 pp. Solonenko, V. P. (ed.) Live Tectonics, Volcanoes, and Seismicity of the Stanovoi Highland - Moscow: Nauka., 1966. - 230 pp. Stupak, F. M. Cenozoic Volcanism in the Udokan Range - Novosibirsk: Nauka., 1987. - 169 pp. Stupak, F. M. Cenozoic Volcanism in the Udokan Range - Novosibirsk: Nauka., 1987. - 169 pp. Xiao, L., Xu, Y. G., Mei, H. J., Zheng, Y. F., He, B., Pirajno, F. Distinct mantle sources of low-Ti and high-Ti basalts from the western Emeishan large igneous province, SW China: implications for plume-lithosphere interactions, // Earth Planet. Sci. Lett., 2004. - v. 228 - p. 525. Xiao, L., Xu, Y. G., Mei, H. J., Zheng, Y. F., He, B., Pirajno, F. Distinct mantle sources of low-Ti and high-Ti basalts from the western Emeishan large igneous province, SW China: implications for plume-lithosphere interactions, // Earth Planet. Sci. Lett., 2004. - v. 228 - p. 525. Xirouchakis, D., Hirschmann, M. M., Simpson, J. A. The effect on the silica content and on mineral-liquid partitioning of mantle-equilibrated melts, // Geochim. Cosmochim. Acta, 2001. - v. 65 - p. 2201. Xirouchakis, D., Hirschmann, M. M., Simpson, J. A. The effect on the silica content and on mineral-liquid partitioning of mantle-equilibrated melts, // Geochim. Cosmochim. Acta, 2001. - v. 65 - p. 2201. Zorin, Yu. A., Turutanov, E. Kh., Kozhevnikov, V. M. Mantle plumes beneath the Baikal rift zone and adjacent areas: geophysical evidence, // Doklady Earth Sciences, 2003. - v. 393a - p. 1302. Zorin, Yu. A., Turutanov, E. Kh., Kozhevnikov, V. M. Mantle plumes beneath the Baikal rift zone and adjacent areas: geophysical evidence, // Doklady Earth Sciences, 2003. - v. 393a - p. 1302.