105 research outputs found

    Facies and sedimentary environments of the Upper Scythian-Carnian succession from the Belanské Tatry Mts., Slovakia

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    The Triassic Fatricum basin studied in the Belanské Tatry Mts. (Slovakia) was a relatively stable and restricted platform area influenced by eustatic and climatic fluctuations. During the early Triassic the platform was influenced by continental clastic sedimentation intermittent with shallow marine transgressions when carbonate sediments formed. Common occurrence of carbonized plat debris suggests relatively humid climatic conditions dominating during this interval (Werfenian facies). Significant climate aridisation was concurrent with the beginning of the Middle Triassic transgression as indicated by evaporitic fabrics common within the entire Middle Triassic carbonate succession. The Middle Triassic has been divided into several lithofacies complexes reflecting the interplays between the eustatic and climatic fluctuations. The lower Middle Triassic complex (lower-middle Anisian?) displays dominance of calcareous sediments indicating free communication with the open ocean. The subsequent intervals are rather uniform facies assemblage composed by dolomites and evaporites formed in a restricted and stagnant basin. The basin has been strongly influenced by subtropical storms, particularly common in the late Anisian. Transgression pulse in the early Ladinian involved growth of microbial colonies building thrombolitic biostromes. Final shallowing by the end of Ladinian led to replacement of carbonate sediments by continental clastics of the Carpathian Keuper. These sediments, mostly of alluvial nature, comprise plant debris what suggests climate pluvialisation in Carnian times

    Neogene karst sinkhole and its deposits from Górażdże Quarry, Upper Silesia : archive for palaeoenvironmental reconstructions

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    A sinkhole, developed in Middle Triassic limestones and filled with clastic and organic deposits, including lignite, was studied, in terms of its origin and age. The sinkhole represents a solution sinkhole, which originated through the subsidence of surficial deposits into an underlying cave system. The study permitted the recognition of three main stages of sinkhole evolution. During the initial stage, subterranean and surface karstification proceeded concurrently. As a result, a terra rossa cover developed at the surface and a cavern system was formed in the underlying bedrocks. During the second phase, both systems became connected and the soil cover subsided. This, in turn, involved the formation of a depression at the land surface and ponding of the drainage water. The pond was filled with plant debris, later giving rise to lignite formation. During the third and final stage, the sinkhole was filled with quartz sands with kaolinite, derived from eroded, Upper Cretaceous sandstones and marls. Results of pollen analysis from the sinkhole indicate the presence of mesophytic forests and show a significant role of riparian forests and herbaceous vegetation. The occurrence of abundant, freshwater algae and the pollen of aquatic plants evidences sedimentation of the infill in a water body (pond). The apparent dominance of arctotertiary and cosmopolitan, palaeofloristical elements, as well as the occurrence of only sparse, palaeotropical elements (mainly subtropical), indicate a warm-temperate climate (cooler than during the Early and Middle Miocene period). A comparison of the sporomorph association from the sinkhole with those from other Neogene sites provides evidence of its Late Miocene age (Late Pannonian-Early Pontian)

    Palynology of Oligocene lignites in two karst palaeosinkholes at Górażdże, Upper Silesia, Poland

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    A palynological analysis was carried out on about 115 samples from two borehole cores, containing the infills of two palaeosinkholes at Górażdże. In both sinkholes, well preserved palynofloras were found in several lignite samples. A total of 54 fossil species, including 5 species of cryptogam spores, 7 species of gymnosperm pollen and 42 species of angiosperm pollen, were identified. No marine palynomorphs or microremains re-deposited from older sediments have been found in these samples. The spore-pollen assemblage made it possible to date the sinkhole deposits. The composition of the assemblage (e.g., abundance of small tricolporate pollen grains of the Fagaceae family, including Cupuliferoipollenites pusillus, Fususpollenites fusus, and Quercoidites microhenricii) indicates that the age of the lignites in both sinkholes is early Oligocene. Thus, the deposits at Górażdże correspond to the 5th Czempiń lignite seam group. The 5th seam occurs mainly in northwestern Poland and its lignites were deposited in isolated wetland basins with marine influences. The terrestrial Górażdże palynoflora without any marine influence shows mainly local early Oligocene vegetation from the surrounding area. The results are also direct evidence of the multiphase palaeokarst of the Silesian-Cracow Upland, including the deposition of lignites of various ages

    Key aspects of the stratigraphy of the Upper Silesian middle Keuper, southern Poland

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    The stratigraphy of the Upper Silesian Keuper, a continental, mudstone-dominated succession is poorly known, although the already renowned, newly discovered vertebrate localities highlight the growing demand for a more precise intra-regional correlation and an appropriate stratigraphic reference framework. A major lithostratigraphic unit, preliminarily proposed for the middle Keuper (i.e., above the Schilfsandstein; Stuttgart Formation in “Stratigraphische Tabelle von Deutschland”, 2002) by Szulc and Racki (2015; Przegląd Geologiczny, 63: 103– 113), is described in detail. The redefined Grabowa Variegated Mudstone-Carbonate Formation, the unit previously based on inaccurately presented information, includes the Upper Gypsum Beds and the Steinmergel-keuper in the traditional scheme from Germany (= Weser and Arnstadt formations). Three members are formally defined: the Ozimek (Mudstone-Evaporite) Member, the Patoka (Marly Mudstone-Sandstone) Member and the Woźniki (Limestone) Member. Two significant bone-bearing horizons (Krasiejów and Lisowice) are placed within the Patoka Mbr. The formation thickness in a composite, regional reference section of the Upper Silesian Keuper, based on the new Woźniki K1 and Patoka 1 well profiles, is approximately 215 m thick. The Grabowa Fm generally correlates with the Norian stage, with the base located in the undefined upper Carnian, and is topped by a major, erosive disconformity and sedimentary sequence boundary, near the Norian-Rhaetian boundary. However, hiatuses in the Silesian middle Keuper succession are located and paired with a cannibalistic type of sand-mud flat deposition, largely controlled by Early Cimmerian movements of tectonic blocks associated with the Kraków–Lubliniec shear zone

    Palynostratigraphy and palynofacies of the Upper Silesian Keuper (southern Poland)

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    The results of the palynostratigraphical studies presented in this paper come from five boreholes Patoka 1, Czarny Las, Woźniki Śląskie K1, Kobylarz 1 and Poręba as well as from four outcrops at Lipie Śląskie, Patoka, Zawiercie and Poręba, in Upper Silesia (southern Poland). The palynostratigraphical zonation presented by Orłowska-Zwolińska (1983) for the epicontinental Upper Triassic of Poland was applied. The palynomorph spectra are marked by different preservation states, combined with the frequent occurrence of reworked specimens, probably even from Palaeozoic strata. The spore-pollen assemblage recognized in the “Chrzanów Formation” belongs to the early Carnian verrucata Subzone of the palynological longdonensis Zone. The spectrum from the Stuttgart Formation represents the Carnian astigmosus Zone. Spectra in the Patoka Marly Mudstone-Sandstone Member (Grabowa Mudstone-Carbonate Formation), with the Lisowice bone-bearing horizon, represent the middle and late Norian meyeriana b Subzone. The Rhaetian age of the bone-bearing succession in the Lisowice–Lipie Śląskie clay-pit suggested in the literature was not confirmed. The age of assemblages from the “Połomia Formation”, which overlies the Patoka Member, was not determined, owing to the poor state of miospore preservation. Moreover, three types of palynofacies were recognized as being characteristic for a fluvial channel (1), a flood plain (2), and lacustrine and playa environments (3) as well as for an undetermined milieu. Type 1 was found in the deposits of the Stuttgart Formation, the Patoka Member and the “Połomia Formation”, type 2 in the Patoka Member and the “Połomia Formation”, type 3 in the “Chrzanów Formation”, the Stuttgart Formation and the Patoka Member
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