Exhumation history of the Tatry Mountains, Western Carpathians, constrained by low-temperature thermochronology

This study tests alternative models for the growth of the Tatry Mountains (Central Western Carpathians) by the application of low-temperature thermochronology. Zircon (U+Th)/He ages from the north of the range are mostly between 48 and 37Ma and indicate cooling prior to the onset of fore-arc sedimentation in the region (42-39Ma). In contrast, zircon (U+Th)/He ages in the south of the range are around 22Ma. Apatite fission track ages across the sampled sites range from 20 to 15Ma. Apatite (U+Th)/He ages range from 18 to 14Ma with little variation with elevation or horizontal location. Based on thermal modeling and tectonic reconstructions, these Miocene ages are interpreted as cooling in the hanging wall of a northward dipping thrust ramp in the current location of the sub-Tatric fault with cooling rates of similar to 20 degrees C/Myr at similar to 22-14Ma. Modeled cooling histories require an abrupt deceleration in cooling after similar to 14Ma to <5 degrees C/Myr. This is associated with termination of deformation in the Outer Carpathians and is synchronous with the transition of the Pannonian Basin from a syn-rift to a postrift stage and with termination of N-S compression in the northern part of the Central Western Carpathians. Overall, the timing of shortening and exhumation is synchronous with the formation of the Outer Carpathian orogen and so the Miocene exhumation of the Tatry records retrovergent thrusting at the northern margin of the Alcapa microplate. ng plate