The paper presents data on relations between the petrofabrics of olivine crystals, elastic properties and thermal conductivity of mantle xenoliths in basalts from the Bohemian Massif, Pannonian Basin, Baikal Rift, and Lanzarote Island (Canary Islands). The sizes of the xenoliths themselves and olivine porphyroblasts and neoblasts in them were proved to be distributed according to the lognormal law. The identified seismic anisotropy of the xenoliths is controlled by the preferred orientation of the axis [100] of the olivine and partial melting zones in the xenoliths. The axes of the maximum shortening of the samples coincide with the dominant distribution mode of the axes [010] of olivine crystals. The major maxima of the axes [001] are parallel to the long axes of the xenoliths, whereas the maxima of [100] plot along the middle axis of the samples. The elastic properties $(V_p)$ and thermal conductivity ($\lambda$) of mantle xenoliths are controlled by parameters of the crystal lattice of olivine and the orientation of partial melting zones, which are correlated with the orientation of the long, middle, and short axes of the xenoliths. These data imply that the geometrically regular shapes of mantle xenoliths had been in situ formed in the mantle before these xenoliths were entrained by melts and brought to the surface.
Seismic anisotropy of the mantle, xenoliths in basalt, partial melting, elastic properties, thermal conductivity
1. Babuska, V., Plomerova, J., Sileny, J. Large-scale oriented structures in the subcrustal lithosphere of Central Europe, // Ann. Geophys., 1984. - v. 2 - p. 649.
2. Bayuk, I. O., Rodkin, M. V. Physical and mathematical modeling of the elastic properties and electrical conduction of rocks by the OSA method, // Physics of the Earth, 1998. - no. 12 - p. 3.
3. Carter, N. L., Ave`Lallement, H. G. High-temperature flow dunite and peridotite, // Bull. Geol. Soc. Amer., 1970. - v. 81 - p. 2181.
4. Christensen, N. L. Elasticity of ultrabasic rocks, // J. Geophys. Res., 1966. - v. 71 - p. 5921.
5. Gass, I. G., Lippard, S. J. , Shelton. A. W. Eds. Ophiolites and Oceanic Lithosphere - Oxford: Geol. Soc.., 1984. - 413 pp.
6. Gibert, B., Schilling, F. R., Tommasi, A., Mainprice, D. Thermal diffusivity of olivine single-crystals and polycrystalline aggregates at ambient conditions - a comparison, // Geoph. Res. Lett., 2003. - v. 30 - p. 5921.
7. Gibert, B., Schilling, F. R., Gratz, K., Tommasi, A. Thermal diffusivity of olivine single crystals and a dunite at high temperature: Evidence for heat transfer by radiation in the upper mantle, // Physics of the Earth and Planetary Interiors, 2005. - v. 151 - p. 129.
8. Grachev, A. F. Rift Zones of the Earth. 2nd edition - Moscow: Nedra., 1987. - 287 pp.
9. Grachev, A. F. Khamar-Daban is a hotspot in the Baikal Rift: chemical geodynamics evidence, // Physics of the Earth, 1998. - no. 3 - p. 3.
10. Grachev, A. F. MORB-like mantle beneath Lanzerote Island, Canary Islands, // Rus. J. Earth. Sci., 2012. - v. 12 - p. 3.
11. Grachev, A. F., Dobrzhinetskaya, L. F. Textural anisotropy of mantle xenoliths in Neogene volcanics in Central Europe and its importance for interpreting the azimuthal seismic anisotropy of the lithosphere // Deep Xenoliths and the Structure of the Lithosphere - Moscow: XENOLITH Project., 1987. - p. 178.
12. Grachev, A. F., Levykin, A. I. New data on the nature of low velocity zone of the rift zones // Abstract of XV Assambly of IUGG - Moscow: Nauka., 1971. - p. 178.
13. Grachev, A. F., Malevskii, A. V. On the viscosity anisotropy of the anomalous mantle, // Dokl. AN SSSR, 1988. - v. 303 - no. 4 - p. 830.
14. Grachev, A. F., Arana, A., Aparicio, A. State and composition of the upper mantle beneath the Canary Islands // Teide Laboratory Volcano Project, Progress Report, Contract: EVSV-CT93-0283 - Madrid: Teide Laboratory., 1994. - p. 21.
15. Grachev, A. F., Blumstein, E. I., Sokolova, E. P., Levykin, A. I. Lherzolite nodules in alkaline basalts of the north-eastern part of the Baikal rift, // Dokl. AN SSSR, 1973. - v. 211 - no. 2 - p. 445.
16. Grachev, A. F., Nikolaichik, V. V., Trubitsyn, V. P. On the nature of the geometrically regular shapes of ultramafic xenoliths in basalt and patterns of their size distribution, // Dokl. AN SSSR, 1985. - v. 285 - no. 6 - p. 1433.
17. Grachev, A. F., et al. On the compositional, textural, and physical heterogeneity of a single spinel lherzolite sample // Deep Xenoliths and the Structure of the Lithosphere - Moscow: XENOLITH Project., 1987. - p. 8.
18. Grachev, A. F., Kondaurov, V. I., Konyukhov, A. V., Magnitsky, V. A. On some numerical solutions of the problem of mantle diapir emplacement in the lithosphere, // Physics of the Earth, 1998. - no. 11 - p. 3.
19. Hess, H. H. Seismic anisotropy of the uppermost mantle under oceans, // Nature, 1964. - v. 203 - p. 629.
20. Johnson, J. S., Gibson, S. A., Thompson, R. N., Nowell, G. M. Volcanism in the Vitim Volcanic Field, Siberia: Geochemical Evidence for a Mantle Plume Beneath the Baikal Rift Zone, // J. Petrol., 2005. - v. 46 - p. 1309.
21. Jung, H., Waff, H. S. Olivine crystallographic control and anisotropic melt distribution in ultramafic partial melts, // Geoph. Res. Lett., 1998. - v. 25 - p. 2901.
22. Karato, S. Deformation of Earth Materials: Introduction to the Rheology of the Solid Earth - Cambridge, UK: Cambridge Univ. Press., 2008. - 462 pp.
23. Kendall, J.-M., Pilidous, S., Keir, D., Bastow, I., Stuart, G., Ayele, A. Mantle upwellings, melt migration and the rifting of Africa: insights from seismic anisotropy // The Afar Volcanic Province Within the East African Rift System, G. Yirgu, C. J. Ebinger, P. K. H. Maguire (Eds.), Special Publications, 259 - London: Geological Society., 2006. - p. 55.
24. Kluegel, A. Reactions between mantle xenoliths and host magma beneath La Palma (Canary Islands): Constraints on magma ascent rates and crustal reservoirs, // Contrib. Mineral. Petrol., 1998. - v. 131 - p. 237.
25. Kneller, E. A., van Keken, P. E., Karato, S., Park, J. B-type olivine fabric in the mantle wedge: Insights from high-resolution non-Newtonian subduction zone models, // Earth and Planet. Sci. Lett., 2005. - v. 237 - p. 781.
26. Kolmogorov, A. N. Probability Theory and Mathematical Statistics - Moscow: Nauka., 1985. - 264-266 pp.
27. Koreshkova, M. Yu. Petrology of mantle xenoliths in alkaline basalts of the Lanzerote Island, Canary Islands, // Vestnik St.-Petersburg University, 1996. - v. 3 - p. 65.
28. Moltchanova, T. V., Ratnikova, G. I. Texture inhomogeneity of xenoliths from Cainozoic basalts of the Khamar-Daban Ridge (Tumbusun-Dulga volcano) // Ultrabasic Xenoliths in Basalt Magmas - Moscow: Nauka., 1996. - p. 100.
29. Mordvinova, V. V., Vinnik, L. P., Kosarev, G. L., Oreshin, S. I., Treusov, A. V. Teleseismic tomography of the Baikal Rift lithosphere, // Dokl. Earth Sciences, 2000. - v. 372 - no. 4 - p. 716.
30. Morin, D., Corriveau, L. Fragmentation processes and xenolith transport in a Proterozoicminette dyke, Grenville Province, Quebec, // Contrib. Mineral. Petrol., 1996. - v. 125 - p. 319.
31. Nicolas, A., Christensen, N. I. Formation of anisotropy in upper mantle peridotites - a review // Structure and Dynamics of the Lithosphere-Astenosphere K. Fuchs, C. Froidevaux (Eds.), System. Geodynamics Series, vol. 16 - USA: AGU., 1987. - p. 111.
32. Nicolas, A., Boudier, F., Boullier, A. M. Mechanisms of flow in naturally and experimentally deformed peridotites, // Amer. J. Sci., 1973. - v. 273 - p. 853.
33. Popov, Yu., Semenov, V. G., Korostelev, V. M., Berezin, V. V. Remote evaluation of the thermal conductivity of rocks using a mobile heat source, // Physics of the Earth, 1983. - no. 7 - p. 86.
34. Raleigh, C. B. Mechanisms of plastic deformations of olivine, // J. Geophys. Res., 1968. - v. 73 - p. 5391.
35. Schmeling, H. Numerical models on the influence of partial melts on elastic, anelastic and electrical properties of rocks. Part I: elasticity and anelasticity, // Phys. Earth Planet. Inter., 1985. - v. 41 - p. 34.
36. Spera, F. J. Carbon dioxide in petrogenesis III: role of volatiles in the ascent od alkaline magma with special reference to xenolith-bearing mafic lavas, // Contrib. Mineral. Petrol., 1984. - v. 88 - p. 217.
37. Tommasi, A., Gibert, B., Selpold, U., Mainprice, D. Anisotropy of thermal diffusivity in the upper mantle, // Nature, 2001. - v. 411 - p. 783.
38. Verma, R. K. Elasticity of several high-density crystals, // J. Geophys. Res., 1960. - v. 65 - p. 757.
39. Volarovich, M. P., Bayuk, E. I., Levitova, F. M. A technique for simultaneous measuring the elastic properties and density of rocks at 20 kbar, // Leipzig Gerlands Beitr$\ddot{a}$ge zur Geophysik, 1977. - v. 86 - p. 69.
40. Volarovich, M. P., Bayuk, E. I., Efimova, G. A. Elastic Properties of Minerals Under High Pressures - Moscow: Nauka., 1975. - 131 pp.
41. Waff, H. S., Faul, U. H. Effects of crystalline anisotropy on fluid distribution in ultramafic partial melts, // J. Geoph. Res., 1992. - v. 97 - p. 9003.
42. Yoder, H. S. Jr. Generation of Basaltic Magma - Washington, D.C: National Academy of Sciences., 1976.
43. Yoshino, T., Matsuzaki, T., Yamashita, S., Katsura, T. Hydrous olivine unable to account for conductivity anomaly at the top of the asthenosphere, // Nature, 2006. - v. 443 - p. 973.
44. Zhao, Dapeng, Lei, Jianshe, Inoue, Tomofumi, Yamada, Akira, Gao, Stephen S. Deep structure and origin of the Baikal rift zone, // Earth and Planet. Sci. Lett., 2006. - v. 243 - p. 681.
