Cubic anisotropy and anisotropic salt
Zandong Sun, R. James Brown
This paper considers the question whether a salt layer is anisotropic or not and what its anisotropic features are. The geophysical classification of salt is carded out based on a combination of velocity measurement and salt-characteristic investigation through thin sections on different salt samples and previous work. A physical modelling was performed to characterize anisotropic salt. It has been found that there are three types of anisotropic salt. The anisotropic features of chevron-crystal salt (widely present in the Whitkow Member of the Prairie Evaporite Formation in the Western Canada Basin) match cubic symmetry quite well. Exact expressions for phase velocities in an arbitrary direction have been derived for cubic symmetry. Group velocity formulae are also developed in symmetry planes.