Original paper

Apatite fission track and (U-Th)/He dating of teschenite intrusions gives time constraints on accretionary processes and development of planation surfaces in the Outer Western Carpathians

Danisík, Martin; Pánek, Tomáš; Matýsek, Dalibor; Dunkl, István; Frisch, Wolfgang


The age of planation surfaces in the Podbeskydská pahorkatina Upland in the Outer Western Carpathians (OWC, Czech Republic) is constrained by low-temperature thermochronological dating methods for the first time. Our apatite fission track and apatite (U-Th)/He data measured on teschenite intrusions show that planation surfaces in the study area formed in post-Pannonian time (>7.1 Ma) and are therefore younger than traditionally believed. This contradicts the classical concepts, which stipulate that a large regional planation surface of Pannonian age (the so-called “midmountain level”) developed in the whole Western Carpathians. Geodynamic implications of our data are the following: (i) the investigated Těšín and Godula nappes of the OWC were buried and thermally overprinted in the accretionary wedge in different ways, and consequently experienced different cooling histories. This indicates a dynamic basin setting with an active accretionary process in a subduction zone; (ii) accretionary processes in the OWC were active already during Late Eocene times.