Seismostratigraphic interpretation of the Cretaceous succession of northern Poland was based on regional geo-seismic transects, consisting, mostly, of unique, high-resolution, regional seismic profiles of the Poland SPANTMseismic survey, calibrated by geophysical, stratigraphic and lithological data from several deep boreholes. The upper Albian - Upper Cretaceous succession was divided into 5 seismostratigraphic units. The seismic facies have also been characterized. So far, the interpretation ofthe regional architecture ofthe Upper Cretaceous sedimentary cover of the East European Craton was commonly based on the classic, layer-cake model, assuming simple correlations of stratigraphic units between boreholes. The regional geophysical profiles from the Poland SPANTMsurvey revealed, however, a more complex picture. Within the upper Albian - Upper Cretaceous succession, two major units have been identified that are divided by regional mid-Upper Cretaceous unconformity. Within this succession, numerous clinoforms and erosional incisions have been recognized that are incompatible with the formerly applied layer-cake model. Two systems of contour currents (N-S and NW-SE) were identified as active during the deposition of mostly syn-inversion Upper Cretaceous succession. A new tectono-sedimentary model of the Late Cretaceous evolution of the shelf basin of northern Poland has been proposed that, which tentatively, linked depositional processes with the progressive lithospheric buckling during mid-Late Cretaceous sub-Hercynian tectonic movements.
Basen łysogórsko-radomski (BŁR) ograniczony był od południa synsedymentacyjnym uskokiem świętokrzyskim o głębokich założeniach skorupowych. Od NE graniczył z basenem lubelskim (BL) wzdłuż wąskiej strefy czytelnej w środkowodewońskim rozkładzie sedymentacji. Jej głębsze założenia stanowił prawdopodobnie uskok podłoża w osiowej części elewacji radomsko-kraśnickiej, wpływający na sedymentację przynajmniej od emsu późnego. BL łączył się od SE z basenem lwowskim, który od wschodu był ograniczony przez lądowy masyw w rejonie tarczy ukraińskiej. Wczesnodewoński etap rozwoju basenów (lochkow–środkowy ems) został zapoczątkowany w sylurze późnym osadami otwartego szelfu, które w lochkowie środkowym i późnym przeszły w osady perylitoralne, przykryte (częściowo niezgodnie ?) grubą serią aluwialną. W etapie środkowodewońskim (późny ems-wczesny fran) szybkie tempo sedymentacji facji węglanowo-terygenicznych otwartego zbiornika BŁR było uwarunkowane przez pogrążanie się bloków podłoża. Natomiast w warunkach stabilnego podłoża BL niewielką przestrzeń akomodacji dla osadów płytkiego szelfu i platformy węglanowej kształtowały głównie transgresje eustatyczne. W etapie środkowo–późnofrańskim, na tę ostatnią tendencję nałożył się puls subsydencji związany z początkiem ryftowania w rowie Prypeci. Etap fameński zaznaczył się powstaniem depocentrum w centralnym segmencie BL i akumulacją niemal 2 km węglanowo-ilastych osadów głębokiego basenu szelfowego i otwartego szelfu, przechodzących ku górze w progradujące ku SW systemy przybrzeżnomorskie i lądowe. Depocentrum utworzyło się w układzie pull-apart między strefą Kocka a uskokiem Ursynowa–Kazimierza, równocześnie z główną fazą ryftowania basenu Prypeci.
EN
Łysogóry-Radom Basin (ŁRB) is bounded in the south by the deeply-rooted Holy Cross Fault. To NE it passes into the Lublin Basin (LB) along a narrow zone clearly reflected in the Middle Devonian depositional pattern. It was probably related to a basement fault along the axial part of the Radom–Kraśnik Elevation affecting deposition at least since the late Emsian onwards. BL continued to the Lviv Basin in SE, which was bordered from the east by the continental Ukrainian Massif. The Early Devonian stage of the basins development started in the latest Silurian with an open-shelf sedimentation passing in the middle to late Lochkovian into marginal marine clastics. This is (partly unconformably) overlain by a thick alluvial complex. Between late Emsian and early Frasnian rapid sedimentation of carbonate-terrigenous open marine facies in the ŁRB was controlled by basement blocks subsidence. On the other hand, under stable cratonic conditions of the BL much smaller accomodation space was generated mainly by eustatic transgressions allowing a mostly shallow-shelf and carbonate platform development. In the Middle Frasnian this pattern was overprinted by a subsidence pulse related to the initial Pripyat Graben rifting. The Famennian stage was marked by a depocentre development in the central LB segment, and an accumulation of nearly 2 km of sediments, starting with carbonate-shaly deposits of a shelf basin and open shelf, passing upwards into marginal-marine and continental systems prograding SW-wards. The depocentre formed in a pull-apartregime between the Kock and Ursynów–Kazimierz faults, parallel with the main phase of the Pripyat Graben rifting.
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Based on lithofacies analysis of clastic, clay and carbonate rocks, wireline logs and sequence stratigraphy, sixteen depositional sequences have been distinguished in the paralic Carboniferous succession of the Lublin Basin from the Visean to the base of Westphalian B. The facies evolution and depositional architecture of the deposits belonging to three types of depositional systems tracts, i.e. lowstand (LST), transgressive (TST) and highstand (HST) have been reconstructed. The sequences are bounded by type 1 basal unconformities formed during subaerial erosion following relative sea-level fall and lowstand. This erosion, that in some cases reached down to the LST deposits of the underlying sequences, mainly affected the HST deposits. Relative sea-level rise controlling the base level of the rivers during lowstand was the basic factor influencing facies development, cyclicity and thickness of fluvial deposits, as well as the vertical and lateral transformation of rivers in theparalic Carboniferous succession. Vertical transition of high- to low-energy fluvial environments can be observed within the LST. The LST deposits typically occur in incised shelf valleys and in non-incised fluvial systems. Within the LST of sequences 2 and 4 to 10 commonly occur medium and large systems of simple incised valleys that developed in a coastal-plain system. The LST of sequences 11 to 15 comprises large systems of compound incised valleys that developed in a piedmont system. Relative sealevel rise in the late lowstand, sea-level oscillations during transgression and highstand and the volume of sediment supply were the main factors influencing facies development, cyclicity, thickness and lateral distribution of the deltaic deposits, shallow-shelf shales and limestones. Within the TST commonly occur coarsening-upward and non-gradational cyclothems that correspond to parasequences and were formed in the distal parts of the inner-shelf delta lobes. In the HST, the most commontypes are coarsening-upward cyclothems developed during the progradation of innershelf delta lobes and small lake deltas, as well as non-gradational cyclothems formed in lakes on a delta plain without influence of delta lobes. The transgression of sequence 7 probably had the widest extent of all the sequences in the paralic Carboniferous succession of the Lublin Basin. It was presumably much wider to the N, NE and NW than the presently accepted boundaries of the basin. Based on analysis of three curves of relative sea-level changes in the paralic Carboniferous succession of the Lublin Basin and the transgressive-regressive curve for the Carboniferous of Western Europe, the sequences distinguished have been correlated with the chronostratigraphic scheme for the Carboniferous System. The diachronous commencement of sedimentation has been confirmed and evaluated. The lack of deposits of sequence 5 in the eastern part of the basin suggests the presence of a stratigraphicgap encompassing the upper Brigantian. The position and range of stratigraphic gaps present elsewhere in the basin has also been indicated. In the north-westernmost and easternmost parts of the study area the gap has the widest range, encompassing the upper Arnsbergian to lower Marsdenian strata. The mid-Carboniferous boundary between the Mississippian and Pennsylvanian has been located at the base of sequence 8.
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