f Anisotropic and velocity dispersion of finely layered media

Fine layering is one of the geological systerns that more frequently contribute to the formation of sedimentary basins. Moreover, the constituents of a fine layered medium are among the cornponents of reservoir rocks: sandstones and Iirnestones, for instance, which are the recipient rocks, and shales which form the seal rocks. By fine layering we mean that the dominant wavelength of the seismic putse is much longer than the thicknesses of the individual Iayers. When this occurs, effective anisotropy takes place. Moreover, in the presence of hydrocarbons, the media may show substantial attenuation properties and velocity dispersion. This is the case with poreus or cracked rocks like sandstones and limestones, respectively, and even shale formations with considerable fluid content.