Quantitative texture analysis of slates: An insight into slate’s elastic properties and their contribution to the understanding of seismic wave reflections in anisotropic materials

Authors

  • Saúl Álvarez Arias Dpto. Geología, Universidad de Salamanca
  • Juan Gómez Barreiro Dpto. Geología, Universidad de Salamanca.
  • Imma Palomares Dpto. Geología, Universidad de Salamanca.
  • Juan Morales Sánchez-Migallón Dpto. Geología, Universidad de Salamanca.

DOI:

https://doi.org/10.55407/geogaceta99820

Keywords:

seismic anisotropy, reflection coefficient, crystal preferred orientation (OCP), slate, stiffness tensor

Abstract

Slates are low-grade metamorphic rocks characterized by an alignment of the phyllosilicates, resulting in the development of a marked foliation. A consequence of this is a strong directional dependence of their elastic properties, which are tightly bound to their texture. The Rietveld analysis applied to synchrotron x-ray diffraction images of slates from the Truchas Syncline (NW Iberian Peninsula) will provide us with the orientation distribution function (ODF) of the principal minerals that constitute the rock. This textural analysis shows an exceptional alignment of phyllosilicates (muscovite and chlorite) in contrast with a poor orientation of other minerals such as quartz. In a later treatment of the data, the elastic properties of the slates, as well the variations of the seismic wave velocities, have been calculated from the ODF and the single crystal stiffness tensors. The results of both the elastic properties and the wave velocities can be used for the construction of models that allow to understand the reflections of seismic waves in markedly anisotropic materials, which is a matter of a great interest in the studies of the Earth’s lithosphere with seismic methods.

References

Aki, K., and Richards, P. G. (1980). Quantitative Seismology: Theory and Methods, vol. 1. W.H. Freeman and Co., 557 p.

Blangy, J.P. (1994). Geophysics, 59 (5), 775-781. https://doi.org/10.1190/1.1443635

Christoffel, E.B. (1877). Annali di Matematica Pura ed Applicata, 8, 193-243. https://doi.org/10.1007/BF02420789

Cárdenes, V., Rubio-Ordóñez, A., Wichert, J., Cnudde, J.P., and Cnudde, V. (2014). Earth-Science Reviews, 138, 435-453. https://doi.org/10.1016/j.earscirev.2014.07.003

Cárdenes, V., López-Sánchez, M.A., Barou, F., Olona, J., and Llana-Fúnez, S. (2021). Tectonophysics, 808, 228815. https://doi.org/10.1016/j.tecto.2021.228815

García-Guinea, J., Lombardero, M., Roberts, B., and Taboada, J. (1997). Transactions of the Institution of Mining and Metallurgy B: Applied Earth Sciences, 106, 205-2014.

Forjanes, P., Gómez-Barreiro, J., Morales, J., Astilleros, J. M., & Fernández-Díaz, L. (2020). CrystEng Comm, 22(35), 5743-5759. https://doi.org/10.1039/D0CE00755B

Lutterotti, L., Vasin, R., and Wenk, H.R. (2014). Powder Diffraction, 29 (1), 76-84. https://doi.org/10.1017/S0885715613001346

Martínez-Catalán, J.R., Arenas, R., Abati, J., Sánchez-Martínez, S., Díaz-García, F., Fernández-Suárez, J., González-Cuadra, P., Castiñeiras, P., Gómez-Barreiro, J., Díez-Montes, A., González-Clavijo, E., Rubio-Pascual, F.J., Andonaegui, P., Jeffries, T.E., Alcock, J.E., h, Díez-Fernández, R., and López-Carmona, A. (2009). Comptes Rendus Geoscience, 341, 114-126. https://doi.org/10.1016/j.crte.2008.11.004

Mookherjee, M., and Mainprice, D. (2014). Geophysical Research Letters, 41, 1506-1513. https://doi.org/10.1002/2014GL059334

Tsvankin, I. (2001). Seismic signatures and analysis of reflection data in anisotropic media, 1st Edition. Pergamon, Oxford, 456 p.

Rietveld, H.M. (1969). Journal of Applied Crystallography, 2, 65-71. https://doi.org/10.1107/S0021889869006558

Wenk, H.R., Matthies, S., Donovan, J., and Chateigner, D. (1998). Journal of Applied Crystallography, 31, 262-269. https://doi.org/10.1107/S002188989700811X

Wenk, H.R., Kanitpanyacharoen, W., and Renc, Y. (2019). Journal of Structural Geology, 125, 319-324. https://doi.org/10.1016/j.jsg.2017.12.009

Wenk, H.R., Yu, R., Cárdenes, V., López-Sánchez, M.A., and Sintubin, M. (2020). Journal of Structural Geology, 138, 104066. https://doi.org/10.1016/j.jsg.2020.104066

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Published

2022-06-06

How to Cite

Álvarez Arias, S., Gómez Barreiro, J., Palomares, I., & Morales Sánchez-Migallón, J. (2022). Quantitative texture analysis of slates: An insight into slate’s elastic properties and their contribution to the understanding of seismic wave reflections in anisotropic materials. GEOGACETA, 71, 23–26. https://doi.org/10.55407/geogaceta99820

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