Młodszy paleogen jednostki dukielskiej w Karpatach Słowackich i próba jego powiązania z paleogenem polskim

Abstract

Upper Paleogene of the Dukla Unit in the Slovak-Carpathians and an attempt for parallelizing it with the Polish Paleogene Former investigations of the Upper Paleogene of the Dukla Unit resulted in somewhat different ideas of the content and sequence of the individual lithologie complexes in Poland and in Slovakia. In the Polish part of the Dukla unit the following lithostratigraphic units were distinguished (Teisseyre, 1930, 1932; Warchałowska-Pazdrowa, 1930; Ślączka, 1959), beginning with the lowest: Hieroglyphic Beds (flysch sandstones and shales) Globdigerina marls, Lower Menilite Beds (calcareous shales, silicified shales, cherts, Mszanka sandstones), Cergowa Beds (Flysch sandstones and micaceous shales), Upper Menilite Beds (siliceous-argillaceous shales, cherts, sandstones); Krosno Beds (flysch sandstones and shales with mica). In the stratigraphical profile the Menilite beds alternate with the Krosno faciès (the Cergowa and the Krosno beds). Such a sequence may be denoted as the Menilite — Krosno Series. In the upper part of the Cergowa beds, immediately below the Upper Menilite Beds, is a correlation horizon of the so-called Tylawa Shales (limestones) (Jucha 1969). It is thin intercalation of laminated limestones without globigerines. Several hundred meters higher up, amidst the Krosno Beds is another correlation horizon, the so-called Jaslo Shales, with structure analogous to the former, and with globigerines. The litostratigraphic units described are ranged to the Middle Eocene and the Upper Eocene — Oligocene (Bieda et al., 1963; Blaicher & Ślączka, 1963; Jucha & Kotlarczyk, 1961). The Upper Priabonian Globigerina marls are best evidenced paleontologically. As regards dating the Cergowa Beds and the Menilite Beds as Upper Priabonian, it seems doubtful because of possible redeposition of fauna (see Ślączka, 1971). In Eastern Slovakia (Lesko, 1958—64; Lesko, Nemćok & Korab, 1960; Korab et al., 1966) there was distinguished the following stratigraphie sequence: the Hieroglyphic beds (= Submenilite Beds) are overlain by the Menilite Beds. In the southern structures of the Dukla unit, between these beds, are the Papin Beds (Lesko, 1958) gradually wedging out north-eastwards. The Menilite Beds are overlain by claystone- sandstone beds termed as the Krosno Beds in literature. Regarding their age, the Papin beds are ranged — on the basis of planktonie microfauna — to the upper part of the zone of Globigeraspis index, and to the zone of Globigerina officinalis, Priabonian. The bottom part of the Krosno Beds is of Lower Oligocene age (Samue l & Sal aj , 1968; Korab et al., 1966). The authors found another upper complex of the Menilite Beds in Certiżne, and a correlation horizon of laminated limestones (without globigerines) amidst the Krosno Beds of the Medzilaborce syncline (Fig. 1). The facies of the main horizon of the Menilite Beds is almost the same in all the structures with the exception of the Menilite Beds in Dara. There amidst the Krosno Beds is an Upper Menilite complex, too, only in a facies different from that in Certizne. The authors’ purpose was to treat in detail the profiles of the Upper Paleogene and to correlate the Polish and Slovak beds in question. The results of field observations facilitated compilation of a lithologie profile representative of all the structures (Fig. 1, 2, 3) with the exception of the Ruské syncline. On the grounds of the main lithologie components, the Papin Beds may be regarded as the oldest part of the Krosno — Menilite Series. Other lithologie components, like silicified sandstones together with marls of the Łącko type, form thicker accumulations in the Hieroglyphic Beds, or form passage beds with less Menilite- Krosno components. Regarding lithology, the Menilite Beds may be divided into three parts. The bottom complex consists of brown calcareous claystones with interbedded sandstones of the Mszanka type in the north-western part of the unit, and with sandstones of the Krosno type in south-eastern part. The middle complex comprises siliceous — argilaceous shales and cherts. The top part of the Menilite beds consists mostly of hard calcareous claystones (marls), white at weathering. Only in the Dara syncline the top complex („c ”) consists of soft marls. The higher Menilite complex is a facies of siliceous — argillaceous shales with cherts, in this structure. In contrast to that, the upper Menilite complex in Certiżne (the Medzilaborce syncline) exhibits a nature of calcareous claystones with sandstones of the Krosno type. Parallelizing the Menilite — Krosno series in Poland and in Slovakia, we considered several variants (Fig. 4A, B, C). The first based upon lithologie resemblance between the Papin and the Cergowa beds, was excluded because of: (1) the varied manner of transition between the Papin and the Menilite beds (gradual), and that between the Cergowa and the Menilite beds (sudden); (2) in laminated limestones from Certizne globigerines are missing and the correlation with the Jaslo shales of Poland is obstructed. In the second variant considered are former ideas about the Menilite — Krosno Series (e.g. Bieda et al. 1963): the Menilite Beds in the Dukla unit, and in the northern Silesian unit are supposed to form one stratigraphie horizon. Local alterations in their thickness are due to lense—shaped Cergowa beds. In accordance with this interpretation, the Papin Beds should correspond to Globigerina marls, and the Slovak Krosno Beds to the Polish one. It is, however, difficult to parallelize laminated limestones of Certizné with the Jaslo shales; the more that there is no southward wedging — out of the Cergowa Beds between the Lower and Upper Menilite Beds. Most probable is the last variant. It is in accordance with most facts and with the dynamic model of the history of the geosynclinal basin. The variant is best supported by laminated limestones of Certizne correctable with the Tylawa shales, and by a higher complex of the Menilite shales of the Medzilaborce syncline correlatable with the Upper Menilite beds of Poland. The variant is further reasoned by: (1) Hthological similarity of claystone — sandstone Cergowa beds in the southern structures of the Polish part of the Dukla unit with the Krosno beds in East Slovakia; (2) similarity of the Lower Menilite beds in Poland with the main horizon of the Menilite beds in East Slovakia. The only slight shortcoming of the variant is older age of the Cergowa beds in Poland in contract to their younger equivalent in Slovakia. However, since the age of the Cergowa beds was most, likely determined on the basis of resedimented foraminifers the argument need not be regarded as unambiguous. After all, the latest microfaunal data (Blaicher 1970; Ślączka 1971) evidence the Lower — Oligocene age of the Cergowa beds in Poland, and the age is identic with that of the Krosno beds in Slovakia. According to the variant all beds in East Slovakia formerly denoted as the Krosno beds, correspond with the Cergowa beds in Poland. Only in the Medzilaborce syncline with the most complete profile of the „Krosno” beds among all structures of East Slovakia, the beds situated approx. 80 m above the laminated limestones may correspond to the Upper Menilite beds in Poland. The Krosno beds proper have no equivalent in Slovakia. If the interpretation presented in Fig. 4D-2 is right, then in the Dara syncline the beds situated above the upper complex of the Menilite beds may correspond to the Krosno beds. The parallelization is, however, denied by other interpretation of the lithological profile of the Dara syncline (cf. Fig. 4D-1, 4D-3). Supposing the third interpretation were right (Fig. 4C, 4D-3), the upper complex of the Menilite beds in the syncline would be a wedge of the Menilite facies amidst the Cergowa beds. In the authors’ opinion, by the Papin beds sedimentation of the Menilite- Krosno series commenced. The existence of a source area for the sandstones of the Papin beds to the east of the sedimentation basm contradicts Lesko’s (1958) idea of the Magura facies controlling the genesis of the Papin beds. The presence of combined Magura — Dukla facies in the Papin beds is also rejected by Korab & Durkovic (1973). As regards age, the Papin Beds are evidently Upper Eocene, corresponding to the Globigerina marls in Poland. Ranging the Papin Beds in the Menilite — Krosno series is well reasoned by the character of their lithologie profile. The above statements are in accordance with a former thesis on a diachronic course of the bottom boundary of the Menilite — Krosno series in the Carpathians, by Jucha & Kotlarczyk (1961). Lastly S amu e l (1973) inclined to accept the thesis. Accordingly, if in the Silesian Unit the Globigerina marls deposited, then in the southern part of the Dukla Unit the deposition of the Papin beds took place. During the deposition of the thin so-called sub-chert beds in the Silesian Unit and in the northern part of the Dukla Unit, thick calcareous claystooes with initerbeds of the Mszarika aind the Cergowa sandstones deposited in the axial part of the baisün. Straitilgralphie boundary between the Eocene and Oligocene is most likely amidst the Lower Menilite beds with cherts.