Bellow are imaged data from offshore South America (the data was provided by Amoco).
The Figure shows 3 eta curves (an anisotropy measure) overlaying an imaged section. These three curves correspond to their respective position on the section and were extracted from anisotropic inversion. The white sub-horizontal curves are a crude interpretation of the shale-sand discontinuities that can be extracted from the three curves and from following the reflections apparent on the image. The basic idea here is that shales induce anisotropic behavior of wave propagation (Banik, 1984), while sands do not.
All information above are extracted from only P-wave surface seismic data. Imagine the implications of this toward deep water exploration where the cost of drilling is high. By the way, the above interpretation ties well (but at a lower resolution) with information extracted from a well log in the area.