Coupling sequential restoration of balanced cross sections and low-temperature thermochronometry: The case study of the Western Carpathians

Abstract

In this paper, a new approach is applied to test a proposed scenario for the tectonic evolution of the Western Carpathian fold-and-thrust beltforeland system. A N-S balanced section was constructed across the fold-and-thrust belt, from the Polish foreland to the Slovakia hinterland domain. Its sequential restoration allows us to delineate the tectonic evolution and to predict the cooling history along the section. In addition, the response of low-temperature thermochronometers (apatite fission-track and apatite [U-Th]/He) to the changes in the fold-and-thrust belt geometry produced by fault activity and topography evolution are tested. The effective integration of structural and thermochronometric methods provides, for the first time, a high-resolution thermo-kinematic model of the Western Carpathians from the Early Cretaceous onset of shortening to the present day. The interplay between thick-and thin-skinned thrusting exerts a discernible effect on the distribution of cooling ages along the profile. Our analysis unravels cooling of the Outer Carpathians since ca. 22 Ma. The combination of thrust-related hanging-wall uplift and erosion is interpreted as the dominant exhumation mechanism for the outer portion of the orogen. Younger cooling ages (13-4 Ma) obtained for the Inner Carpathian domain are mainly associated with a later, localized uplift, partly controlled by extensional faulting. These results, which help unravel the response of low-temperature thermochronometers to the sequence of tectonic events and topographic changes, allow us to constrain the tectonic scenario that best honors all available data.

Multiple low-temperature thermochronology constraints on exhumation of the Tatra Mountains: New implication for the complex evolution of the Western Carpathians in the Cenozoic

“…It has been recognized more than 100 years ago that uplift and exhumation of the Tatra Mountains was accommodated by the W‐E trending Sub‐Tatra fault, which separates the Tatra horst from the CCPB sediments of the Liptov Basin in the south [ Uhlig , ]. However, despite its crucial importance, not only for the genetic models of the Tatra Mountains exhumation but also for the tectonic regime in the northern CWC, the geometry, kinetics, amount of displacement, and timing of the fault's activity remain controversial [e.g., Andrusov et al ., ; Bielik et al ., ; Castelluccio et al ., ; Hrušecký et al ., ; Kohút and Sherlock , ; Lefeld , ; Maheľ , ; Petrík et al ., ; Sperner , ; Sperner et al ., ]. The Sub‐Tatra fault is a polygenetic fault system, consisting of several segments that experienced complex tectonic evolution dominated by strike‐ and oblique‐slip movements [ Bac‐Moszaszwilli , ; Sperner , ; Sperner et al ., ].…”

Building and exhumation of the Western Carpathians: New constraints from sequentially restored, balanced cross sections integrated with low‐temperature thermochronometry

“…[] but also the fault kinematics recorded by mineral shear fibers (quartz, epidote, and carbonates) and striae on slickenside surfaces [ Jurewicz and Bagiński , ]. In addition, the low‐T thermochronometric data predicted by the tectonothermal modeling performed on a regional geological section across this area shows a good match with the real low‐T thermochronometric ages [ Castelluccio et al ., ].…”

“…Cooling ages ranging between 20 and 15 Myr characterize the western Polish OC successions, whereas a more recent exhumation event (8–20 Myr) involves the PKB deposits. Cooling ages for the PKB are consistent with the published exhumation ages for the IC domain [ Burchart , ; Baumgart‐Kotarba and Král , ; Danišìk et al ., , , , , ; Śmigielski et al ., , ], thus suggesting a common cooling event for these two different tectonic domains, as shown in our structural model [see also Castelluccio et al ., ]. Forward modeling allowed us not only to validate the geological cross sections and contextualize the thermochronometric data sets but also to calculate the shortening rate for each step of the reconstructed tectonic evolution.…”

Deciphering exhumation and burial history with multi‐sample down‐well thermochronometric inverse modelling

“…The two approaches can in fact be complementary, as the thermo‐kinematic model can be used to fit only the final portion of the thermal history as delineated by the thermal history model (e.g. Castelluccio et al ., ; Mora et al ., ).…”

“…One method is to use thermo‐kinematic models (Braun, , ; Lock & Willett, ; Valla et al ., ; Van der Beek et al ., ; Pedersen et al ., ; Erdős et al ., ; Almendral et al ., ; McQuarrie & Ehlers, ), which place samples in a geological context and then constrain the parameters of that context, such as exhumation rates, landform development or fault motion, based on comparison with thermochronometric data. A key feature of thermo‐kinematic models is that they also establish a spatial and structural context between samples, and it is becoming increasingly common to use this approach to evaluate structural scenarios (Erdős et al ., ; Castelluccio et al ., ; McQuarrie & Ehlers, ). Alternatively, one can extract solely the thermal history information, independent of direct geological context but perhaps constrained by relevant information such as crystallization age, deposition time and temperature, or burial history (Green et al ., ; Gallagher, , ; Issler, ; Ketcham et al ., ; Ketcham, ).…”