Calculation of 3D strain in Qaleh-Zari mine shear zone (South of Birjand)

Mineralization in Qaleh-Zari copper mine has occurred as a vein type and in the fractures of dextral shear zone with N135 trend. The azimuth of main fractures in order of significance is NW-SE, NE-SW, ESE-WNW according to dominant fault trend in the area, and they are orderly in the same trend with riedel and anti-riedel and extension fractures. The veins are in two phases, and follow the shear zone geometry. Simultaneous with increase of shear strain, primary vein phase has gained dextral rotation and then second vein phase has formed, therefore, the type of eformation in the area is non-coaxial. Average of strain ratios indicates constructional strain ellipsoid in flinn diagram for the area. Ramsay logarithm drawing using main strain plate logarithmic ratio also confirms oblate form strain ellipsoid for area. Relation between three parameters, υ ¡K-value, k describing strain ellipsoid, strain ellipsoid shape of study area could be general oblate form. Dilatation value is 0.59 with mohr circle method.