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Palaeontological analysis of Middle Miocene siltstones at Wiślica (Carpathian Foredeep, Poland)

Płonka K.

Geologos

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2017

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Vol. 23, No. 1

29--43

EN

Middle Miocene siltstones of the Skawina Formation that crop out at Wiślica, within the axial part of the Carpathian Foredeep in Poland, were analysed. The deposits studied contain numerous benthic and planktonic foraminifera, ostracods, echinoid spines, bryozoans, bivalves and otoliths. The fossils recognised document an early ‘Badenian’ (= Langhian in the Mediterranean area), or, more precisely, ‘Moravian’ age of the deposit. Palaeoecological analysis suggests normal-marine conditions with full salinity. The studied siltstones were deposited from middle–lower shoreface to lower–offshore, warm surface water and locally suboxic to dysoxic conditions in the sediment.

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Lithostratigraphy and regional significance of the Nowa Słupia Group (Upper Silurian) of the Łysogóry Region (Holy Cross Mountains, Central Poland)

Kozłowski W.

Acta Geologica Polonica

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2008

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Vol. 58, no. 1

43-74

EN

The Ludlovian-Lochkovian succession of the Łysogóry Region of the Holy Cross Mountains (Central Poland) represents an infill of a Caledonian foreland basin situated at the SW margin of the East European Craton (EEC). The facies pattern and transport directions indicate that the source area was located westward from the basin and was separated from the Baltica mainland by the epicratonic sea. The 2.5 km thick succession, defined here as the Nowa Słupia Group, has been subdivided into 9 formations (from bottom to top: Trzcianka, Trochowiny,Winnica /Rachtanka, Sarnia Zwola /Bronkowice, Podchełmie, Rudki and Bostówformations).A revised lithostratigraphic scheme has been constructed. The lower part of the Nowa Słupia Group (Trzcianka and Trochowiny formations) represents the underfilled stage of the basin development and is composed of flysch-like sediments. The upper part of the group represents the filled to overfilled stage of the basin. In the latter stage the lateral migration of two main facies: red continental deposits (represented by the Rachtanka and Podchełmie formations) and open shelf hemipelagic sediments (represented by the Sarnia Zwola and Rudki formations and referred here to the Podlasie facies), is observed. The lateral facies migrations probably resulted from eustatic fluctuations. The two main facies zones are separated by a narrow belt of neritic sediments (represented by the Winnica, Bronkowice and Bostów formations),which are known for their rich benthic fauna. The facies trends observed show that during the latest Ludlovian through early Pridolian, the boundary between the continental and marine facies in the Łysogóry Region was oriented parallel to the Baltica margin (NNW-SSE).

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Development and inversion of Devonian and Carboniferous basins in the eastern part of the Variscan foreland (Poland)

Narkiewicz M.

Geological Quarterly

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2007

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Vol. 51, No 3

231-256

EN

The Polish part of the Central European Variscan foreland includes several regional units that differ in crustal structure and are characteried by distinct Devonian to Carboniferous subsidence and depositional histories. These units responded differently to palaeostress changes along the south ernmargin of the Old Red Continent. During the Devonian to Namurian A, areas located to the south-west of the Teisseyre-Tornquist Zone (TTZ), including the Upper Silesian Coal Basin, Małopolska and Łysogóry-Radom blocks, were influ nced by stress fields similar to those in the west ward adjacent Rheno-Hercynian Zone, whilst the Lublin Basin, located to the north-east of the TTZ, shows a similar development to the Pripyat-Dniepr-Donets rift system. After the Namurian A, the entire southern Pol ish foreland started to respond in a more consistent way to the build-up of synorogenic compressional stresses, implying a more uniform development of the stress field. During the Namurian B to early Westphalian D, the Polish foreland was dominated by north-directed compressional stresses emanating from the Southeastern Variscan Belt. During the late Westphalian and early Stephanian, the entire foreland under went compressional deformation and concomitant basin in version under the influence of stresses propagating from the Moravian-Silesian Foldand-Thrust Belt. In the Polish foreland, the development of Devonian-Carbon if erous basins, as well as the architecture of Variscan structures, clearly reflect the reactivation of preexisting crustal discontinuities, including specifically the TTZ, but also other major geophysically defined crustal bound aries. In general, thick-skinned tectonics controlled by the inherited structural grain of the basement prevailed, whereas structural decoup ling, resulting in the development of minor thrusts and reverse faulting, was of local significance only. The distinct structural-depositional development of the Pomerania region reflects its distal location with respect to the evolving orogen. Orogenic compression influenced this area only indirectly, with the TTZ acting as a guide for the transmission of transtensional and transpressional stresses.

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Geodynamiczne i tektoniczne uwarunkowania ewolucji basenów przedgórskich, z odniesieniami do zapadliska przedkarpackiego

Krzywiec P.

Przegląd Geologiczny

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2006

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Vol. 54, nr 5

404-412

EN

Main geodynamic and tectonic mechanisms responsible for evolution of foreland basins and their sedimentary infill are discussed. They include flexure of the lower lithospheric plate and its extension, growth of the orogenic wedge and sedimentation / erosion within the foreland basin. Recently formulated models of foreland basin system include four major depositional zones that are characterised by various tectono-sedimentary processes. Of particular importance for evolution of foreland basins is very complex interplay of tectonics and sedimentation, and significant lateral shift of tectonic and depositional zones. Evolution of frontal part of the orogenic wedge could be deciphered using growth strata i.e. depositional sequences formed in vicinity of growing thrust-related structures. Certain aspects of Miocene (Late Badenian–Sarmatian) evolution of the Polish Carpathian foredeep basin are discussed in a context of presented models of foreland basins.