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TECTONOTHERMAL EVOLUTION OF THE CENTRAL-WESTERN CARPATHIANS AND THEIR FORELAND
Full text linkThe tectonic and thermal evolution of the Carpathian thrust and fold belt-foreland system is a topic of great interest both for the occurrence of potential oil and gas fields and for the presence of any enigmatic features that needs an alternative interpretation to the commonly accepted models proposed so far. This study is focussed on the area including the southern Poland, the western Ukraine and the crystalline complex and its sedimentary cover cropping out in the Western Slovakia.
The analysis of such a complex tectonic scenario is carried out by the construction of new balanced and sequentially restored cross-sections integrated with low-Temperature (low-T) thermochronometry. Coupling these data it is possible to provide a thermo-kinematic model honouring both the presented structural model and the thermochronometric data and, at the same time, validate the proposed tectonic scenario.
Five balanced cross-sections were constructed from the foreland to the Inner Carpathian domain. Cross-section building and balancing are performed using Move, software dedicated to the kinematic restoration. These sections were then integrated with new apatite fission track and apatite (U-Th)/He data to constrain the last cooling event. Although the cooling of the Inner and the Outer Carpathians are well documented in literature, no low-T thermochronometric data are present from the Pieniny Klippen Belt located between them. Apatite fission track and apatite (U-Th)/He analysis were performed on five samples made of siliciclastic sandstones coming from this narrow belt .Both the balanced sections and low-T thermochronometric data were processed with FETKIN, software developed at The University of Texas in Austin in collaboration with Ecopetrol and dedicated to low-T thermochronometric age prediction and forward modelling. This processing allows to define the evolution of the thermal field through time.
Basing on a review of the sedimentological and stratigraphic works, the Outer and the Inner Carpathian successions are interpreted as deposited in the same sedimentary domain and the Pieniny Klippen Belt as a sedimentary unit deposited in the proximal part of the Inner Carpathian foreland basin, overthrusted on the Outer Carpathian deposits during the Late Eocene. The Mesozoic olistoliths and olistostromes forming the Pieniny wildflysh are here interpreted as coming from the eroded Mesozoic cover of the IC range. New apatite fission track and apatite (U-Th)/He data coming from the Pieniny Klippen Belt constrained its last cooling event to the Middle-Late Miocene, coeval with the cooling of the Inner Carpathian region. The balanced cross-sections show a progressive increasing of the Outer Carpathian shortening moving to the east (from 60% in the Polish region to 64% in the Ukrainian Carpathians). Furthermore, the cross-sections constructed in the central part of our study area highlight the relevant role of the post-thrusting low-angle normal faults in the exhumation process of this area. On the other side, no evidences of post thrusting normal faults occur in the Ukrainian region, where published low-T thermochronometric data suggest an exhumation triggered mainly by regional uplift.
In this work the suggested tectonic scenario is successfully tested with FETKIN, to demonstrate that thrusting is the principal mechanism controlling the exhumation ages of the Western Polish Carpathians and to evaluate the effects of subsidence, topography and tectonics on the thermochronometric age prediction.
Coupling low-temperature thermochronometry and sequential restoration of balanced cross-sections: new constraints on the tectonic evolution of the western Carpathians (Poland, Slovakia and Ukraine)
No full textTectonothermal evolution of the Polish and Ukrainian Outer Carpathians: interplay between erosion and extensional tectonics within exhumation
No full textCoupling sequential restoration of balanced cross sections and low-temperature thermochronometry: The case study of the western carpathians
Full text linkIn this paper, a new approach is applied to test a proposed scenario for the tectonic evolution of the Western Carpathian fold-and-thrust belt-foreland 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
Building and exhumation of the Western Carpathians: New constraints from sequentially restored, balanced cross sections integrated with low-temperature thermochronometry
Full text linkWestern 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
Burial and exhumation history of the Polish Outer Carpathians: Discriminating the role of thrusting and post-thrusting extension
No full textEarly-orogenic deformation in the Ionian zone of the Hellenides: Effects of slab retreat and arching on syn-orogenic stress evolution
Full text linkIn this work we report on early-orogenic fracture patterns affecting a Cretaceous to Eocene sedimentary succession exposed in western Greece. These rocks belong to the Cenozoic External Hellenides, which form the western portion of the Aegean orocline. The analysis of fracture type, orientation, and crosscutting relationships provides constraints on the stress and strain patterns during the early stages of orocline formation. The fracture patterns in the study area includes early-orogenic extensional fractures arranged into two mutually orthogonal sets. These developed during progressive burial in the forebulge-foredeep system, ahead of the advancing compressive front. Tectonic solution seams at a high angle to bedding postdate these extensional structures. Solution seams are arranged in different sets, oblique to each other, and developed in the early stages of thrusting and folding. Extensional structures and solution seams are oblique to each other. Their orientation and crosscutting relationships provide evidence for clockwise vertical axis rotation of stress directions with time. This is consistent with the progressive arching of the forebulge-thrust belt system during progressive slab retreat
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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