Structural data from Skupniów Upłaz Mountain (Tatra Mts., Poland)

The study area was situated along Skupniów Upłaz Mountain in the larger Tatra Mts, southern Poland. An investigation was carried out in Inter Carpathians, in Kriżna Unit. The limestone and dolomites of anisian and ladinian built this mountain. Beds of limestone and dolomite form a homocline in study area. A dominant orientation of strike and dip has value 110/42N. There are found many small-scale tectonics structures in this area. There were distinguished two groups of stylolitic seams, the en echelon fractures, five sets of fractures and three sets of normal faults. These structures served to reconstruct structural evolution of this small region. Firstly, when beds were in horizontal position, there was a vertical stress, which caused a lithostatic stylolitic seam. Afterwards, the tectonics stylolitic seams, the en echelon fractures and the hybrid fractures were formed before folding, when beds were in horizontal position. The tectonics stylolitic seams are formed after lithostatic stylolitic seams were created, when a horizontal stress was oriented N-S. The en echelon fractures were formed after tectonics stylolitic seams. The right-slip en echelon fractures and the sinistral en echelon fractures were found in study area. A stress orientation was impossible to define, because the en echelon fractures were irregular orientation after rotation to horizontal position. A system of hybrid fractures was formed, when a stress was oriented W-E. This system is composed of a set of fractures number IV and a set of fractures of number V. These sets are complementary. A dominant orientation of set of fractures number IV has value 77/55S. A dominant orientation of set of fractures number V has value 118/51S. Thirdly, there were took place a folding and Kriżna Unit was made. The reverse faults were found in study area. Unfortunately, they have a varied orientation and they couldn’t create a set, so there is no information about a stress orientation during this stage. A rotation uplift of Tatra Mts. took place after folding. After this event a set of normal fault and a set of fractures number III was formed together, when a stress was oriented ENE-WSW. An orientation of set of normal faults has values 162-173/80-90N. A dominant orientation of set of fractures number III has value 166/80N. In the end, a system of normal faults and a system of fractures was formed, when a stress was oriented WNW-ESE. An orientation of system of normal faults has values 9-45/70-80N and S. A system of fractures is composed of a set of fractures number I and a set of number II. A dominant orientation of set of fractures number I has value 20/88N. A dominant orientation of set of fractures number II has value 37/80S.