|
| | Abstract | | Biotite schists and shales have TI anisotropy produced by aligned sheet layers of phyllosilicate minerals, with the symmetry axis perpendicular to the planes of planar microstructures in rocks. The anisotropy is characterized by the slow and fast P waves along the symmetry axis and in the isotropic plane, respectively. There is a large velocity difference between SH and SV -qS- in the isotropic plane. In the off-axis directions, the S-waves have polarity exchange between the fast and slow shear waves. These characteristics are strongly affected by aligned cracks. The axial anisotropy is more pronounced with increasing crack density, but the shear-wave splitting in the off-axis directions is masked by cracks and the velocity diffrence fades out with increasing crack density. |
|
|
|
| |
|