Exhumation history of the Tatry Mountains, Western Carpathians, constrained by low-temperature thermochronology
Sinclair, H. D.
Stuart, F. M.
- Publisher: Wiley
(U+Th)/He | Apatite fission track | /dk/atira/pure/subjectarea/asjc/1900/1906 | /dk/atira/pure/subjectarea/asjc/1900/1908 | Central Western Carpathians | Exhumation | Geophysics | Tatry | Geochemistry and Petrology
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 to 37 Ma and indicate cooling prior to the onset of forearc sedimentation in the region (42–39 Ma). In contrast, zircon (U + Th)/He ages in the south of the range are around 22 Ma. Apatite fission track ages across the sampled sites range from 20 to 15 Ma. Apatite (U + Th)/He ages range from 18 to 14 Ma with little variation with elevation or horizontal location. Based on thermal modelling 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 ~20 °C/Myr at ~22-14 Ma. Modeled cooling histories require an abrupt deceleration in cooling after ~14 Ma to <5 °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 post-rift 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 record retro-vergent thrusting at the northern margin of the Alcapa microplate.