Flisz magurski południowej części Gorców

Ludwik Watycha

Abstrakt


MAGURA FLYSCH OF THE SOUTHERN PART OF THE GORCE MTS

Summary
The area under discussion comprises the southern part of Gorce, between Lepietnica and Dunajec rivers, near Krościenko.
The area in study belongs to the southern facies of the Magura flysch. The facies embraces here a belt, in which two tectonic units have been formed, viz.: Turbacz unit and "near-klippen zone". The first unit comprises Gorce and the group of Radziejowa, the second one embraces a belt south of the overfold line Niwa-Wżar-Krościenko.
The sediments of the Magura flysch of the southern facies are characteristic of the predominance of sandstones over the schists. This series being of Turonian?-Maestrichtian-Danian age, bas been subdivided, from bottom to top, into the Nowy Targ beds or inoceramian beds in the southern facies and into the overlying them hieroglyphic beds of Palaeocene-Lower Eocene age.
The clayey and dusty fraction (schists) increases in this series from west to east, and from south to north, disappearing, however, almost exclusively toward the top part. Within the Sub-Magura beds of middle Eocene age, the sandstone sand conglomerates prevail over the schists, whereas in the Magura beds (upper Eocene) they are main constituent. Within the older beds than the Magura ones, there appear marly interbeddings of Łąck type, or interbeddings of claystones resembling those of Łąck. In sandstones there occur conglomeratic siltstone banks of various thickness with pebbles of various rocks.
The crystalline components of these beds belong to the continental barrier, which was not tied up with the Tatra Mts. The sedimentary formations belong to a group, the rocks of which do not contain the components of the Pieniny Klippen Belt. The great continental complex constituted by the Tatra Mts, Pieniny Klippen Belt and the Magura barrier, was cut, before the Senonian time, by overfold lines into huge blocks. This complex underwent, from Turonian up to Eocene, some movements characteristic of such an appearance that the northern and central parts of the blocks mostly plunged, and the southern parts uplifted. These movements were the resultant of a radial movement, changeable in time and space, and of a constant tangential movement directed toward the north. The sub-flysch and sub-klippen belt basements were divided into blocks, which moved down and up, and twisted under the influence of stress.
Shortening of the basement reaches in the upper Eocene time its critical point. The newly laid down and partly folded cover of sediments does not find room within its previous frames and enters at first upon the remnant of the Magura barrier, presses if forward, and then invades the area of the klippen belt. In the Oligocene, a huge mass of the Podhale flysch rakes up the klippen belt series, earlier scaled off, and folds them together with the Magura flysch series. At that time, this latter displaces on the newly formed Silesian units being destroyed by erosion.
As the results of such a situation, large shortening of both sub-flysch and sub-klippen belt basements followed. In the area south of the overfold Niwa-Wżar-Krościenko, the final folding process led to a formation of numerous folds and overthrust sheets, tectonically strongly disturbed, which may reveal the wedged in klippen belt elements. Within the Turbacz unit, a synclinal element has formed (Lubań syncline), as if slipping under the folds of the near-klippen belt zone. Because of the andesite effusions, CO2 mineralization and other phenomena, the overfold line is of great tectonical importance there, and the fact that exactly this line makes only the boundary of the Pieniny Klippen Belt may not be excluded.

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