Structural and tectonic investigation were performed in the "Olkusz-Pomorzany" zinc and lead mine, within uplifted fault blocks (horsts) as well as on upthrown sides of tectonic faults. In the adjasency of faults, three or four systems of cracks have been distinguished.

Cracks ascertained on upthrown (uplifted) sides of chosen faults show wider fissure gaps in comparison to those described in downnthrown fault sides (grabens). Wide crack gaps of strongly obligue systems are typical for tensional stress conditions. For appropriate recognition of tectonic stress character, it would be interesting to give evidence regarding, strongly obligue towards faults, tensional systems of cracks in upthrown fault sides. Tensional stresses, acting within tectonic horsts and in perpendicular or similar direction towards frame horst dislocation, are responsible for creation low-angle, tensional systems of cracks.