Problemy tektoniki podłoża a rozwój struktur pokrywy wschodniej części Karpat polskich

Jan Kuśmierek, Roman Ney

Abstrakt


TECTONIC PROBLEMS OF THE BASEMENT VS. THE COVER'S STRUCTURES EVOLUTION IN THE EASTERN PART OF POLISH CARPATHIANS

Summary
The present stage of studies on epigeosynclinal orogens is characterized by searching of connections between the evolution of sedimentary-diastrophic cycles and the lithosphaere's structure. The complicated, formed in several tectonic phases, geostructural plane of the Carpathian arc makes those studies complicated.
Analysis of the geostructural plane, either of the cover or the elements of deep orogene's basement, brings to the conclusion that the folded/napped belt of Carpathian externides reflects, in surface projection, a compressive mega-suture of the lithosphaere (Fig. l).
The connection between geostructural elements of the cover, their foreland and basement induces the authors to accept such a geodynamic model, in which structural - facial units of externides were formed in result of centripetal subduction of the lithosphaere blocks underlying geosynclinal subbasins with neoalpine flysh.
Performed in past few years in the Baster Polish Carpathians magnetotelluric probings showed, that the top of consolidated basement, which is connected with high - resistance horizon (about 104 mm), lays on higher depths than it was belived before. Its tectonics is characterized by deeply sunken zones elongated concordantly with structural depressions in the cover.
In oppinion of the present authors, the new picture of the basement tectonic is correlated both with the kinematic mode modele of neoalpine deformations reflected by isotyme map and with the present - day geological structure (Fig. 2).
On that background, some substantial connections between the basement structure and the cover's deformations evolution are discussed. Those connections are derived from the Late Oligocene - Early Miocene geosynclinal - palaeostructural plane, i.e. before the main phase of folding - overthrusting movements. In that aspect the genetical conditioning of regional depressions and elevations and mechanism of forming of overthrusts is deducted.
Independently of the tectogenetic aspect, those problems are important for oil prospecting in deeply sunken structural elements. It' speccialy concerns the NW continuation of deep folds of Borysław-Pokucie unit in the Baster part of Polish Carpathians, taking under consideration, among others, the results of super - deep Kuźmina l borehole.

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