Character and structural evolution of the Mała Łąka Fault in the Tatra Mts., Carpathians, Poland

Abstract

The Mała Łąka Fault in the Tatra Mts. is a synsedimentary normal fault responsible for the variable thickness of Eocene deposits in the area. Its main activity took place in the interval from the sedimentation of red conglomerates to the appearance of nummulitic limestones. The estimated throw is up to 350 m. Near the northern margin of the Tatra Mts., the trend of the fault changes from N–S to NE–SW. This part of the fault could have been activated during the Neogene uplift of the Tatra Mts. and rejuvenated as a sinistral fault. In the upper reach of the Mała Łąka Stream, the fault trend does not follow the course of the Mała Łąka Valley. Here, the flowing stream waters used extensional fractures within a damage zone associated with the Mała Łąka Fault rather than the lithological boundary at the tectonic contact between the Triassic dolomites and the Eocene conglomerates. The fault has a hingelike character; its hinge was located in the present-day Kościeliska Valley, c. 2.5 km west of the Mała Łąka Valley.