A New Approach to Studies of Tectonic Jointing in Fault Zones

Studies of large normal, thrust, and strike-slip faults in Sayan-Baikal mountain province show that the pattern of faulting involves three conjugate systems of joints roughly perpendicular to each other (with variations from 15 to 20°). They must be produced by small-scale crustal elastic deformations under triaxial compression. Spatial orientation of the triplets within an influence zone of a fault is controlled by fault geometry and can provide a basis for recognizing blocks deformed under similar conditions, which is important for tectonic reconstructions.