Wyniki wyszukiwania - Biblioteka Nauki

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Reconstruction of stress directions in the Magura and Silesian Nappes (Polish Outer Carpathians) based on analysis of regional folds

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Szczęsny R.

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tom Vol. 47, No 3

289-298

EN

Statistic analysis of the bed orientation in the Magura and Silesian Nappes was performed in order to establish the directions of regional fold axes. On this ground, variations of the main horizontal stress directions were inferred for both nappes. In the Late Oligocene, in the foreland of the northwards moving Adriatic Microplate, a fan-like pattern of the 1 stress trajectories was formed. Initiation of the Magura Nappe and the related regional folds began in such conditions. Evolution of the regional compression involved clockwise rotation from S-N to SW-NE direction. The rotation was caused by the Early Miocene oblique collision of the Carpathian Orogen with the East European Platform. The pattern of fold axes in the Silesian Nappe reflects this rotation.

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Bentonitized tuffites in the Lower Eocene deposits of the Subsilesian Unit (Western Outer Carpathians, Poland): lithology, stratigraphic position and mineral composition

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Cieszkowski M. , Środoń J. , Waśkowska-Oliwa A. , Leśniak T.

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tom Vol. 76, No 2

197-214

EN

New occurrences of bentonitized tuffites were described from numerous outcrops of the Lower Eocene flysch rocks of the Subsilesian Unit. These deposits crop out in the Żywiec tectonic window and in the tectonic windows of the Lanckorona - Żegocina Structural Zone. The bentonitized tuffites, composed of almost pure dioctahedral motmorillonite, form numerous thin layers and laminae, only occasionally exceeding 5 cm. The age of the tuffites is estimated as the Early Eocene (Glomospira div. sp. and Saccamminoides carpathicus zones) on the basis of foraminiferal assemblages. They occur in the upper part of green shales and in the lower part of the Lipowa beds that consist mainly of muddy turbidites represented by green or green-brownish shales with rare intercalations of sandstones. The sedimentary sequences with the tuffite intercalations form a lithostratigraphic level in the Subsilesian Unit called in the present paper "the Glichów Tuffite Horizon". This tuffite horizon could probably be correlated with deposits of similar age containing tuffites which are known from the Magura, Silesian and Skole nappes.

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Laminowane konkrecje węglanowe z łupków krośnień- skich w oknie tektonicznym Świątkowej Wielkiej (wschodnia część polskich Karpat zewnętrznych)

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Bojanowski M.

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tom Vol. 49 nr 7

627-630

PL

Kilka typów konkrecji węglanowych zostało zebranych z łupków krośnieńskich (górny eocen-najwyższy oligocen). W niniejszej pracy opisane zostały najbardziej charakterystyczne - konkrecje laminowane. Posiadają one dyskoidalne i elipsoidalne kształty i składają się z dwóch typów lamin: brunatnych marglistych i szarych wapiennych. Oprócz mikrytowego kalcytu jako głównego składnika obu typów lamin, pierwszy typ zawiera także minerały ilaste (głównie illit) stłoczone pomiędzy kryształami kalcytu, podczas gdy drugi rozproszone ziarna kwarcu i dolomitu we frakcji mułowej. Wytrącający się z wód interstycjalnych kalcyt musiał najpierw spoić laminy luźnego osadu a następnie rozpychać poszczególne jego ziarna. Skorupki otwornic planktonicznych występują wyłącznie w obrębie lamin marglistych, ponieważ zostały zdeponowane wraz z zawiesiną frakcji ilastej. Laminy są równoległe na całej swej długości, co wskazuje na najwyżej nieznaczne tempo kompakcji podczas wzrostu konkrecji. Organizmy penetrujące osad docierały do konkrecji kiedy te były jeszcze miękkie ale już utworzone i składające się z obu typów lamin: marglistych i wapiennych. Ponadto dinocysty wypreparowane z konkrecji są wyjątkowo dobrze zachowane i nie posiadają oznak wpływu kompakcji. Tak więc badane konkrecje laminowane powstawały podczas przerwy w depozycji tuż pod dnem morza i uległy wczesnodiagenetycznej lityfikacji. Szczeliny septariowe powstały po wstępnym zlityfikowaniu konkrecji i następnie zostały wypełnione miodowym kalcytem.

EN

Several types of carbonate concretions were collected from the flysch Krosno shales (upper Eocene-uppermost Oligocene). This paper describes the most characteristic type - laminated concretions. They are discoidal to ellipsoidal in shape ami consist of two types of laminae: brown marly, and gray calcium carbonate ones. Apart from micritic calcite (principal constituent ot both types of laminae), the brown marly concretions consist also of clay minerals (mainly Mite) infilling calcite intergranular spaces. whereas the second type is highlighted by scattered aleuritic quartz and dolomite grains. The calcite precipitating from interstitial water must have originally cemented laminae ofloose host sediment and then displaced sediment grains. Planctonic joraminijer tests occur exclusively within the marly laminae because they were deposited together with suspended clayey particles. The laminae are parallel which indicates that the compaction rate during the growth of concretions was extremely slow. Yet, organisms penetrating the host sediment reached the concretions when they were still soft, but already formed and composed of these two types of laminae: marly, and calcium carbonate ones. Moreover, dinocysts, extracted from these concretions, are exceptionally well-preserved having apparently avoided compactional flattening. Therefore, the examined laminated concretions formed during a deposition break close to the water-sediment interface, and underwent early-diagenetic lithification. Septarian cracks were produced after primary: lithification, and subsequently filled with light brown calcite.

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New biostratigraphic data on the Ropianka Formation in the Przemyśl area (Skole Nappe, Polish Outer Carpathians) : a clue to understanding the timing of exotic material redeposition

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Woyda J. , Waśkowska A. , Remin Z.

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tom Vol. 67, No. 4

art. no. 45

EN

The geology of the Carpathian orogen in the Przemyśl area shows a diverse array of rock ages and tectonics. However, due to complicated tectonic settings and limited exposures, establishing the precise ages of selected sections and their structural arrangement is challenging. A particularly contentious aspect is the uncertain age of the exotic-bearing layers in the region, with previous age dates ranging from Neocomian to Miocene, leading to significant age discrepancies even for the same sections. Therefore, the need for well-defined age determinations is crucial. To address this issue we established precise biostratigraphic constraints on selected sections in the northern part of the Skole Nappe, specifically within the Ropianka Formation developed as marly and silty deposits with carbonate sandstones and exotic material including large olistoliths. Planktonic and calcareous benthic foraminifera from the exposures studied indicated the lower upper Maastrichtian, embracing the interval of the Racemiguembelina fructicosa and lower part of the Abathomphalus mayaroensis zones. Additionally, re-evaluation of the data of Bukowy and Geroch (1956) from the Iwanowa Hill section indicated its late Maastrichtian age, not the early Maastrichtian as previously inferred. Based on this new biostratigraphic data, the deposits of the Zielonka section are here reclassified to belong to the Leszczyny Member, and not the Paleocene Wola Korzeniecka Member as proposed by Gucik (Geroch et al., 1988). The sections studied seem to mark the lower age-limit of the redeposition of exotic material cropping out in the marginal part of the Gruszowa-Prałkowce Thrust Sheet.

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Zastosowanie cyfrowego modelu terenu (DEM) w badaniach geologicznych na przykładzie obszaru między Dobczycami a Mszaną Dolną (polskie Karpaty zewnętrzne)

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Chodyń R.

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tom Vol. 52, nr 4

315-320

EN

This paper is a preliminary report on using the Digital Elevation Model (DEM) and Shaded Relief Image in geological mapping in the Carpathians. Digital processing of the topographical maps in 1:25 000 scale enabled 3D visualization of a fragment of olish Outer Carpathians, situated between Dobczyce and Mszana Dolna villages. This permitted a preliminary interpretation of lin - eaments occurring in the study area and recognition of correlation between the lineaments and geological structure of the Carpathians Flysch Units. The picture of the Shaded Relief Image was compared with existing remote sensing data such as radar and satellite images, and with results of geological mapping carried out by author in the field. The recognized lineaments can reflect fault zones in the flysch cover and in the consolidated basement. The correlation of lineaments detected in the digital models with discontinuities confirmed in outcrops demonstrates the value of digital methods in geological cartography.