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Comparisons of longitudinal (compressional) wave velocity with structural subfabrics have been made for Yule marble, Newberry Crater pumice, and Salisbury granite. Velocities were (1) measured omnidirectionally in spherical specimens by an ultrasonic pulse technique and (2) plotted and contoured on equal area nets. These contour patterns show velocity anisotropy that can be interpreted in terms of elastic symmetry. Microstructural subfabrics were determined from oriented thin sections of the specimens. Subfabrics were then displayed on equal area nets for comparison of their symmetries with those of the longitudinal wave velocities. The two structural subfabric elements selected for comparison were crystallographic orientation of constituent anisotropic minerals and shape and orientation of pores or cracks. The longitudinal velocity symmetry in Yule marble appears to be axial, whereas in both Newberry Crater pumice and Salisbury granite the pattern is orthorhombic. The pattern of longitudinal velocity anisotropy is associated with preferred orientation of calcite optic axes in Yule marble, preferred orientation of elongate vesicles in the Newberry Crater pumice, and preferred orientation of microfractures in quartz in the Salisbury granite. A prospectus given suggests that the petrophysical technique described can be used to determine elastic symmetry, orient rock to inherent elastic symmetry axes, indicate sample homogeneity, and supplement conventional petrofabric techniques.

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