SPWLA Glossary

The property of a rock which allows it to show different responses or measurements when measured along different axes. Microscopic anisotropy relates to the variation of a property measured perpendicular to the bedding from that measured parallel to the bedding because plate-like mineral grains and interstices tend to orient themselves parallel to the bedding. Macroscopic anisotropy relates to the variation resulting from thin beds and fracture planes whose properties differ appreciably from those of the remaining volume over which a measurement is made.