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The Open University's repository of research publications and other research outputs Influence of palaeoweathering on trace metal concentrations and environmental proxies in black shales

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.

Western Carpathian orogeny has been the subject of intense scientific debate due to the occurrence of enigmatic features, leading several authors to provide contrasting geological models. In this paper, a new interpretation for the tectonic evolution of the Western Carpathians is provided based on the following: (i) an analysis of the stratigraphy of the Mesozoic‐Tertiary successions across the thrust belt domains, (ii) a reappraisal of the stratigraphy and sedimentology of the “tectonic mélange” (i.e., the so‐called Pieniny Klippen Belt) marking the suture between the Inner and Outer Carpathians, and (iii) the construction of a series of balanced and restored cross sections, validated by 2‐D forward modeling. Our analysis provides a robust correlation of the stratigraphy from the Outer to the Inner Carpathians, independently of the occurrence of oceanic lithosphere in the area, and allows for the reinterpretation of the tectonic relationships among the Inner Carpathians, the Outer Carpathians, and the Pieniny Klippen Belt and the exhumation mechanisms affecting this orogenic belt. In order to constrain the evolution during the last 20 Ma, our model also integrates previously published and new apatite fission track and apatite (U‐Th‐Sm)/He data. These latter indicate a middle‐late Miocene exhumation of the Pieniny Klippen Belt. In this study, the recent regional uplift of the Pieniny Klippen Belt is described for the first time using a 2‐D kinematic model for the tectonic evolution of the Western Carpathians.

In the last decades, multidiscipline investigation of the Apennine mountain belt of peninsular Italy has provided fundamental insights into the genesis and evolution of wedge-top basins. In this study, we focus on shallow-water to continental, Pliocene–Quaternary basins that formed on top of the southern Apennine allochthonous wedge after its emplacement onto a large foreland carbonate platform domain (Apulian Platform). The wedge-top basins analyzed in this study are mostly asymmetric, being bounded to the north by a normal fault showing evidence of synsedimentary activity. The basin successions are generally deformed by open folds and reverse faults resulting from shortening coeval with the sedimentation of the Lower Pliocene to lower–middle Pleistocene, upper part of the basin fill. Anisotropy of magnetic susceptibility data from the basin successions are consistent with a basin evolution characterized by an initial stage of tectonic subsidence controlled by roughly north-northwest–south-southeast-oriented extension, followed by southwest–northeast shortening active during subsequent basin filling. The latter shortening is marked by a dominant northwest–southeast mean trend of the magnetic lineation obtained from most sites in the study area and is interpreted as a result of upward propagation of deep-seated deformation (tectonic inversion) taking place within the buried Apulian Platform sitting in the footwall to the allochthonous wedge. Therefore, our results emphasize a complex interplay of different tectonic processes controlling wedge-top basin development.

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