Morphotectonic configuration of the Podtatranská Kotlina Basin and its relationship to the origin of the Western Carpathians

Abstract

In tectonically active regions, many aspects of the topography can provide clues to morphotectonic development. Morphological lineaments have varying degrees of reliability as indicators of neotectonic movement. Here, eleven lines of evidence are assessed and combined for the Podtatranská Kotlina Basin (PtK) between the Tatra and Low Tatra (Nízke Tatry) Mountains, the highest topography of the Western Carpathians. This permits identification of the configuration of structural-neotectonic blocks and documentation of their behaviour. Specifically we 1) evaluate the reliability of fault mapping results, 2) assess relative uplift and subsidence accommodated by the faults, 3) evaluate the intensity of fault movement and 4) explore the role of fault movement in the tilting of blocks. We define 358 structural-neotectonic blocks in the PtK region, providing an exceptionally detailed morphotectonic analysis. Distinction of two stages of neotectonic uplift provides explanation of the regional discrepancy between intensive neotectonic activity and limited recent seismicity with Mw < 5. The first stage, in the Pliocene-Early Pleistocene, was characterized by isostatic uplift linked to delamination and/or convective removal of an over-thickened lithosphere. The second stage during the Late Quaternary involved more complex uplift, including the probable influence of episodic mantle flow induced by the load of the Scandinavian Ice Sheet on northern Europe. This resulted in a change in the extension and configuration of structural-neotectonic blocks, the movements of the Tatra block now measured by GNSS, and the interaction of neotectonic activity with effects of glacial–interglacial transitions.