Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 30

Liczba wyników na stronie
first rewind previous Strona / 2 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  paleogen
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 2 next fast forward last
EN
All the Paleogene represents a key period in the growth of the Alpine belt and the development of surrounding sedimentary basins. Nevertheless, one of the most intriguing timelapse is represented by 10 Ma, between ca. 40 and ca. 30 Ma, when the growing belt hosted volcanic complexes that lead to the accumulation of volcanogenic sequences within the Northern Alpine and the Southern Alpine foreland basins. Such sequences present peculiar characteristics that varies depending on the period and depocenter where they where accumulated. In addition, they represent the fundamental clue to reconstruct how the volcanic arc developed, which kind of volcanic activity characterized it, where the volcanoes were located and to speculate about how magmatism was produced before coming to the surface. Volcanic sequences are, in fact, extremely rare and confined to the west of the chain, disarticulated from the source-to-sink systems that supplied detritus to the depocenters, together with dikes crosscutting the southern part of the belt, so less is the geodynamic information gain from them. The present talk will review a decade of investigation carried out on stratigraphic, petrographic and geochemical data on the different volcanogenic sequences, trying to reconstruct the relationship between putative volcanic centers and the basins, as well as to understand the nature of the Paleocene volcanic arc/arcs. All the considered sequences are characterized by large amounts of volcanogenic detritus, and sometimes they rarely preserve pyroclastic deposits. Occasionally, such sequences are also mixed with non-volcanic detritus, a component useful in tracing provenance of sediments and giving clues about palaeoenvironments constituting the growing belt. Although beyond of being exhaustive, the present communication represents a first attempt in marking fundamental temporal and palaeogeographic steps in the evolution of a volcanic arc through several millions of years on one of the most fascinating orogenic belt.
EN
New findings of crustacean decapod brachyurans from the Rupelian period (lower Oligocene) in Iran are presented in this study. In particular, Lophoranina sp. and Palaeocarpilius cf. P. rugifer Stoliczka, 1871, from the Rupelian strata were found in two previously unexplored localities, Abshar and Vezg near Yasuj in the southwestern region of Iran. The discovery contributes to fill the gap in the record of brachyuran decapod crustaceans in Iran during the Eocene and Miocene periods. The presence of both genera in the Oligocene of Iran suggests a certain degree of faunal similarity among brachyurans on both sides of the Tethys Realm.
EN
The Oligocene (Rupelian) Byram Formation (Vicksburg Group) in Alabama, USA, is divided into three members, including (in ascending order) the Glendon Limestone, unnamed marl, and the Bucatunna Clay. The Oligocene marine units in Alabama have been historically under-investigated, but bulk samples recently obtained from Glendon Limestone Member exposures at site AWa-9 in Washington County yielded 20 unequivocal elasmobranch and teleost taxa. This surprisingly diverse paleofauna, based on isolated teeth, bones and otoliths, includes the new taxon, Gobiosoma? axsmithi sp. nov., as well as “Aetomylaeus” sp., Albula sp., Aplodinotus gemma Koken, 1888, Ariosoma nonsector Nolf and Stringer, 2003, Balistidae indet., Citharichthys sp., Myliobatoidei indet., Diretmus? sp., Hemipristis sp., Negaprion aff. N. gilmorei (Leriche, 1942), Pachyscyllium sp., Paralbula sp., Physogaleus sp., Preophidion meyeri (Koken, 1888), Sciaena pseudoradians (Dante and Frizzell in Frizzell and Dante, 1965), Sciaenops? sp., Sparus? elegantulus Koken, 1888, Sphyraena sp., and Syacium sp. Additional remains were recovered but could not be identified beyond undetermined Elasmobranchii or Teleostei. All these taxa represent first occurrences within the Glendon Limestone Member in Alabama, and the “Aetomylaeus” sp., Pachyscyllium sp., Paralbula sp., and Sciaenops? sp. specimens represent the first occurrences of each in the Oligocene of the Gulf Coastal Plain of the USA. We also report the first record of Oligocene Paralbula Blake, 1940 teeth, and the first occurrence of an Oligocene member of the Balistidae in the Western Hemisphere. This marine vertebrate assemblage indicates that the Glendon Limestone Member at site AWa-9 represented a subtropical to temperate, middle shelf paleoenvironment with a paleowater depth interpreted as 30–100 m.
EN
The Campanian-Paleocene Jaworzynka Formation, a part of the Magura Nappe succession in the Polish Outer Carpathians, is described in terms of its detailed litho- and biostratigraphy. The formation stretches along the marginal part of the Siary Unit, from the Jaworzynka stratotype area in the Silesian Beskid Mts up to the Mszana Dolna area in the Beskid Wyspowy Mts. Its equivalent in the Moravskoslezské Beskydy Mts of the Czech Republic is the Soláň Formation. In the stratotype area, the formation displays complex structure. We distinguish four lithological units, i.e., Biotite Sandstone and Shale (I), Shale (II), Mutne Sandstone Member (III) and Thin-bedded Turbidite (IV) and provide the first detailed biostratigraphy of particular units. The first unit forms the most prominent part of the formation. It was deposited in the Middle Campanian-earliest Maastrichtian within the upper part of Caudammina gigantea Zone up to the lower part of the Rzehakina inclusa Zone. The second unit occurs only locally and its age is limited to the Maastrichtian, to the Rzehakina inclusa Zone. The third unit is composed of thick-bedded sandstones that in some parts may form more than the half of the total thickness of the formation. It is Late Maastrichtian-Danian in age and is placed in the upper part of the Rzehakina inclusa Zone and the lower part of the Rzehakina fissistomata Zone. It is usually covered by a thin package of thin-bedded turbiditic sandstone and shales of Danian-Thanetian age with foraminifera of the Rzehakina fissistomata Zone.
EN
Balanomorph cirripedes from the Eocene–Oligocene of the Hampshire Basin (United Kingdom) and the Middle Eocene of the Cotentin Peninsula, Manche (France) are described. A new genus, Vectibalanus, is founded, with the type species Balanus unguiformis J. de C. Sowerby, 1846; assigned to this are also Balanus erisma J. de C. Sowerby, 1846 and Vectibalanus mortoni sp. nov. In addition, a new species of Lophobalanus Zullo, 1984, L. fresvillensis sp. nov., is described. This is the first record of that genus from outside the eastern USA and the oldest species known to date. Cladistic analysis of 24 morphological characters suggests that Vectibalanus unguiformis is sister taxon to a group comprising the most derived balanomorph taxa, and thus represents an important transition in the evolution of the group, with the initiation of development of a complex parietal wall structure. Vectibalanus unguiformis was evidently adapted to low salinity habitats (10-30 ppt), and is the oldest known brackish water barnacle. The other species (V. erisma, V. mortoni sp. nov.) occupied more clearly marine environments (>30 ppt). Balanomorph barnacles appeared simultaneously in the Priabonian (Upper Eocene) of the Gulf and Atlantic seaboards of the USA and northwest Europe, which probably represents a northerly migration from Tethys.
EN
The Cao Bang Basin is the northernmost of the basins related to the Cao Bang-Tien Yen Fault Zone in northern Vietnam. The basin is filled with a thick series of continental deposits. However, the exact age of the sedimentary basin infill has been under discussion for a long time. Because of new published data, the authors have decided to revisit this basin. Palynological data has allowed us to assign the Cao Bang Basin infill to the Lower Oligocene PC1 complex of the Shangcun Fm. (southern China). Among the saccate grains of gymnosperms, the domination of Cathaya and Pinus was observed, whereas angiosperms are represented by Carya, Celtis, Hammamelidaceae, Ulmus and also Pterocarya, Quercus, the Castanea–Castanopsis–Lithocarpus group, and the Loranthaceae. Among pteridophytes occur Laevigatosporites, Osmundaceae, and Pteris. The sedimentological features of the Cao Bang Basin are distinct from those of other basins from the Cao Bang-Tien Yen Fault Zone. The basin is filled with a wide variety of clastic deposits, from some of coarse-grained, alluvial-fan origin, through sandy beds of fluvial origin up to fine, organic-rich lacustrine deposits. The coarse-grained lithofacies are built of clasts derived mainly from local sources. The sandstones from the basin equally are submature or immature. They contain a lot of lithoclasts, the composition of which depends on the sample location within the basin. The potential source area is composed of older sedimentary units and of granitic rocks. The geochemical samples studied reflect the geochemical composition of silicic source rocks with only a minor contribution of basic components. The succession that fills the basin is interpreted as a typical fill for relatively long-lasting evolving half-graben or strike-slip basins. Moreover, the basin is partly occupied by a subsequent present-day sedimentary basin of Quaternary age.
EN
Triceratium barbadense Greville, 1861a, T. brachiatum Brightwell, 1856, T. inconspicuum Greville, 1861b and T. kanayae Fenner, 1984a, are among the most common diatoms reported worldwide from lower to middle Eocene biosiliceous sediments. Due to complicated nomenclatural histories, however, they are often confused. A morphometric analysis performed herein indicates that T. brachiatum is conspecific with T. inconspicuum, and that both were previously often misidentified as T. barbadense. Triceratium barbadense sensu stricto is a distinct species similar to Triceratium castellatum West, 1860. Triceratium brachiatum and T. kanayae are transferred herein to a new genus, Fenneria, for which a close phylogenetic relationship with Medlinia Sims, 1998 is proposed. A review of the geographic and stratigraphic distribution of Fenneria shows that the best constrained records of its occurrences are found at DSDP Site 338, and ODP Sites 1051 and 1260. The ages of the base (B) and top (T) of each species’ stratigraphic range are calibrated here to the Geomagnetic Polarity Timescale either directly or inferred via correlation with dinocyst biostratigraphy. Latitudinal diachroneity of ~7 million years is documented for F. brachiata, which disappears earlier in tropical and mid-latitude sites than in the northern high latitudes. These observations, coupled with a preliminary compilation of the Chron C20n taxonomic composition of pelagic diatom assemblages for Sites 338, 1051 and 1260, indicate that diatoms diversified palaeobiogeographically considerably earlier than the Eocene-Oligocene Transition, as commonly believed. This study also emphasizes the importance of the detailed examination of specimens from both museum collections and deep-sea cores as a step toward enhancing the utility of Palaeogene diatoms in palaeoceanographic and palaeoenvironmental reconstructions.
EN
The paper discusses the causes of climate change in the latest Cretaceous and the Paleogene (impact event or huge volcanic eruptions?). The climatic evolution (global and – more specifically – in the territory of Poland) during the Paleogene and Neogene in relation to the major climatic events of these periods (PETM, EECO, C4 grassland, Messinian Salinity Crisis) are described and their causes are discussed. Tectonic transformation, volcanic events and earthquakes led to the change in the position of the continents and in the circulation of ocean currents, as well as to increased emission of greenhouse gases – methane and carbon dioxide. These were the main causes of climate changes during the Paleogene and Neogene.
PL
Na podstawie badań przeprowadzonych w obrębie trzech obszarów w Polsce przedstawiono charakterystykę i efekty analiz mikrotermometrycznych inkluzji, występujących w spoiwach i minerałach skał osadowych różnego wieku (od kambru przez perm po paleogen) oraz wypełnionych węglowodorami (HCFI). Inkluzje mają charakter pierwotny i wtórny. Są na ogół jedno- lub dwufazowe. Charakteryzuje je fluorescencja w barwach biało-niebieskich (ropa naftowa) lub niebieskawej (metan), niekiedy żółtej lub czerwonej. Na podstawie barwy świecenia wstępnie oszacowano charakter węglowodorów, które wypełniają te inkluzje i krążą w skałach z tego regionu. Temperatura homogenizacji, która stanowi przybliżenie temperatury zamknięcia fluidu w minerale, wykazuje zmienność związaną z historią geologiczną badanych obszarów. Inkluzje węglowodorów współwystępują w badanych rejonach z inkluzjami solankowymi. Połączenie wyników analiz mikrotermometrycznych inkluzji węglowodorowych z rezultatami badań inkluzji wodnych pozwoliło na szerszą interpretację wyników wszystkich oznaczeń w poszczególnych rejonach. Obecność węglowodorów w inkluzjach świadczy o ich występowaniu i/lub migracji w skałach badanych regionów.
EN
Characteristics and results of microthermometric studies of fluid inclusions which occur in the cements of sedimentary rocks of various ages (from Cambrian through Permian to Paleogene) and filled with hydrocarbons (HCFI) are presented. The inclusions are primary and secondary in origin. They display one or two phases and fluorescence in white-blue (oil) or dull blue (methane) colours, sometimes yellow or red. Based on the fluorescence colour in the ultraviolet light a character of hydrocarbons that fill these inclusions and migrate in the rocks of the region can be estimated. The inclusions are filled with palaeofluids of different compositions. The homogenization temperatures, which correspond to the minimum estimation of the trapping temperatures in minerals, show variability with respect to the geological history of the study area. The hydrocarbon inclusions are often accompanied by brine inclusions. Wider interpretation of all microthermometric analyses was enabled due to the combination of studies on hydrocarbon and aqueous inclusions. The presence of hydrocarbons in inclusions is a proof of their occurrence and/or migration in the rocks of the regions studied.
PL
Celem przeprowadzonych prac było rozpoznanie i zbadanie profilu osadów paleogenu i neogenu, ze szczególnym uwzględnieniem młodszego neogenu, w miejscowości Łęczyce koło Lęborka, gdzie w odsłonięciu w skarpie pradoliny Redy-Łeby stwierdzono występowanie utworów neogeńskich. Posadowiony u podstawy odsłonięcia otwór wiertniczy Łęczyce-Tr osiągnął głębokość 110,0 m p.p.t. i został zatrzymany w utworach formacji mosińskiej dolnej z dolnego oligocenu. Próbki pobrane z odsłonięcia i z rdzenia wiertniczego wykorzystano do badań laboratoryjnych składu ziarnowego (133 analizy), węglanowości osadów (122 analizy), składu minerałów ciężkich (41 próbek) i badań zespołów sporowo-pyłkowych i fitoplanktonu (39 próbek). W profilu otworu wiertniczego rozpoznano osady dolnego oligocenu i miocenu odpowiadające formacjom: mosińskiej dolnej, czempińskiej i mosińskiej górnej (dolny oligocen), gorzowskiej i krajeńskiej (dolny/ środkowy miocen) oraz adamowskiej (środkowy miocen). Stwierdzone w profilu odsłonięcia osady plioceńskie uznano za ekwiwalenty formacji poznańskiej i gozdnickiej. Przeprowadzono korelację stratygraficzną rozpoznanej sukcesji z profilami z obszarów sąsiadujących na terenie północno-wschodniej Polski oraz z Półwyspu Sambijskiego. Wyniki badań umożliwiły odtworzenie warunków sedymentacji osadów, prześledzenie następstwa zbiorowisk roślinnych i implikujących je zmian klimatu. Ze względu na zachowanie pełnego profilu osadów kenozoicznych i stwierdzenie występowania osadów plioceńskich (jedyne stanowisko w tym rejonie), profil z Łęczyc uznano za referencyjny dla Pomorza Wschodniego.
EN
The reported study focused on a complex analysis of Paleogene–Neogene section located at Łęczyce near Lębork (Eastern Pomerania). The lower part of the section is represented by Lower Oligocene to Miocene deposits, drilled by the Łęczyce-Tr well to the depth of 110 m. Its upper part consists of the Late Neogene succession exposed in the slope of the Reda–Łeba palaeovalley just above the drill top. Both core and outcrop sections were sampled for analyses of grain size and composition (133 samples), carbonate content (122 samples), heavy mineral composition (41 samples), and spore-pollen and phytoplankton assemblages (39 samples). For the first time in the Eastern Pomerania, a succession of the standard Lower Oligocene to Pliocene formations has been identified in this section including the Oligocene to Miocene deposits represented by the Lower Mosina Fm., Czempin Fm., Upper Mosina Fm. (Lower Oligocene), Gorzów Fm. and Krajenka Fm. (Lower/ Middle Miocene) and Adamów Fm. (Middle Miocene). Outcrop of the Pliocene deposits (unique in the area), being an equivalent of the Poznań Fm., were described. All the distinguished units were correlated with corresponding sections from the north-eastern Poland and the Sambia Peninsula. The study results have enabled to reconstruct the sedimentary conditions and depositional environments, as well as the succession of floral communities that record the paleoclimatic changes. The Łęczyce section, comprising the Lower Oligocene to Pliocene deposits, is a representative section of the Paleogene–Neogene succession for the whole area of Eastern Pomerania.
PL
Celem prac było rozpoznanie i zbadanie profilu osadów kenozoicznych na południowo-wschodnim obrzeżeniu niecki żytawskiej (ryft Ohrzy) u zbiegu granic Polski, Czech i Niemiec oraz określenie wieku skał osadowych i wulkanicznych związanych z wulkanizmem synsedymentacyjnym. Zlokalizowany w sąsiedztwie miejscowości Markocice otwór wiertniczy Opolno Zdrój PIG-1 osiągnął głębokość 200,0 m p.p.t. i został zatrzymany w utworach podłoża krystalicznego niecki żytawskiej; przewiercono nim cały profil serii osadowej wraz z wulkanitami. Próbki pobrane z rdzenia wiertniczego posłużyły do badań litologiczno-sedymentologicznych oraz laboratoryjnych, w tym do badań mineralogiczno-petrograficznych skał wulkanicznych i do oznaczenia wieku radiometrycznego metodą K-Ar (trzy próbki z rdzenia i jedna próbka referencyjna z odsłonięcia w sąsiedztwie otworu wiertniczego) oraz do badań zespołów sporowo-pyłkowych i fitoplanktonu obecnych w warstwie osadów węglistych nawierconej pod skałami wulkanicznymi (sześć próbek). Skały wulkaniczne datowano na 24,9–32,7 mln lat BP, a zatem utwory te mogły powstać nie później niż w późnym oligocenie. Wyniki badań palinologicznych nie pozwoliły na szczegółowe określenie wieku skał osadowych znajdujących się pod wulkanitami, jednak z superpozycji tych ostatnich wynika jednoznacznie, że są one starsze od górnego oligocenu, a zatem nie mogły powstać później niż we wczesnym oligocenie i stanowią zapewne ekwiwalent stratygraficzny formacji turoszowskiej. Wyniki badań przesuwają zatem początek sedymentacji utworów węglonośnych w niecce żytawskiej co najmniej do późnego paleogenu.
EN
The aim of the study was to identify and examine the Cenozoic strata in the southeastern margin of the Zittau Basin (Ohře Rift) at the crossborder of Poland, Czech Republic and Germany, and to determine the age of the sedimentary and volcanic rocks related to synsedimentary volcanic events. The Opolno Zdrój PIG-1 borehole, located near the village of Markocice, reached a depth of 200.0 m b.g.l. and it was stopped in the crystalline basement of the Zittau Basin, piercing the whole sedimentary series together with the volcanites. A number of sedimentological and lithological studies and laboratory examinations have been performed on samples taken from drill cores. They included (1) a mineralogical/ petrographic study of volcanic rocks and absolute age determination using the K-Ar method (three samples from the borehole and one reference sample from a neraby outcrop) and (2) research of pollen-spore and phytoplankton assemblages from a layer of lignite-bearing sediments lying below the volcanic rocks (six samples). This work determined the age of the covering volcanic rocks at the 24.9– 32.7 million years BP, and therefore, the lignite-bearing rocks may have been deposited no later than the Late Oligocene. Although the results of palynological studies did not allow detailed determination of the age of the sedimentary rocks lying below the volcanites, but the superposition of the latter shows evidently that they are older than the Late Oligocene. They could not have been deposited later than in the Early Oligocene and are probably a stratigraphic equivalent of the Turoszów Formation. Thus, the results move the beginning of sedimentation of the coal-bearing layers in the basin Zittau Basin at least to the Late Paleogene.
PL
Badawczy otwór wiertniczy w Wysokiej Wsi, zlokalizowany w centrum Wzgórz Dylewskich (NE Polska), osiągnął głębokość prawie 490 m, z czego na ponad 400 m przewiercono utwory paleogenu i neogenu. W wyniku badań palinologicznych 47 próbek wyróżniono 13 zespołów palinomorf (sporomorfy, fitoplankton i zoomorfy) i datowano osady. Stwierdzono dwu- i trzykrotne powtarzanie się podobnych zespołów palinomorf w paleogeńskim i neogeńskim odcinku profilu, co wskazuje na silne glacitektoniczne zaburzenie osadów. Udokumentowana w wyniku badań palinologicznych skomplikowana budowa geologiczna odnacza się kilkoma strefami odkłucia i przemieszczenia pakietów skalnych. Najniższy, paleogeński kompleks znajduje się w położeniu pierwotnym, datowano w nim zespoły pyłkowo-fitoplanktonowe: D3–D4 – środkowy paleocen, utwory górnego paleocenu w facji lądowej i D8 – dolny eocen. Na głębokości ok. 455 m występuje pierwsza powierzchnia nieciągłości, gdzie w osady paleogeńskie został wprasowany ponad 100-metrowej miąższości pakiet osadów środkowego miocenu z poziomami sporowo-pyłkowymi V, VI, VIII, IX, XI. Kolejną powierzchnię odkłucia stwierdzono na głębokości ok. 339 m. Na osadach mioceńskich ponownie występuje ok. 60-metrowej miąższości pakiet utworów paleogeńskich, stratygraficznie młodszych od leżących w spągu, datowanych na podstawie poziomów pyłkowo-fitoplanktonowych – górnoeoceński poziom D12 i wykształcone w facji lądowej utwory dolnego oligocenu. W te paleogeńskie osady jest wprasowana kilkumetrowej miąższości seria osadów mioceńskich reprezentująca poziom sporowo-pyłkowy IX. Na głębokości ok. 240 m znów pojawiają się osady środkowomioceńskie ok. 150-metrowej miąższości z poziomami sporowo-pyłkowymi V, VII i IX. Stwierdzone mozaikowe następstwo warstw odzwierciedla skomplikowane procesy glacitektoniczne, które doprowadziły do powstania łusek glacitektonicznych budujących jądro moreny spiętrzonej Wzgórz Dylewskich. W wyniku badań palinologicznych uzyskano unikatowe dane, pozwalające na lokalizację stref odkłuć glacitektonicznych. Brak osadów czwartorzędowych w jądrze moreny spiętrzonej wskazuje na wczesnoplejstoceński wiek deformacji.
EN
The Wysoka Wieś borehole located in the center of Dylewskie Hills (NE Poland) reached a depth of almost 490 metres, with more than 400 metres of the Paleogene and the Neogene deposits. Palynological studies were designed to determine whether this huge Paleogene and Neogene sedimentary complex is located in situ or it has been glacitectonically redeposited. Forty-seven samples were analysed for all palynological matter components, i.e. palynomorphs (sporomorphs, phytoplankton, zoomorphs), palynoclasts (phytoclasts) and inorganic debris. Among the palynomorphs, 13 assemblages have been distinguished. Describing these assemblages from the bottom to the top of the section, dual or triple repetition of the same palynomorph zones indicates a strong glacitectonic deformation of the sediments. Palynological data evidence several disengagement zones and displacement of rock packages. The lowest sedimentary complex occurs in the primary position and it contains the pollen and phytoplankton assemblage D3–D4 of the Middle Paleocene to the Upper Paleocene (terrestrial facies), and the Lower Eocene assemblage D8. At a depth of ca. 455 m there is the first discontinuity zone, along which the over 100-metres thick package of Middle Miocene sediments, containing pollen zones V, VI, VIII, IX and XI, became intruded/ pressed into the Paleogene deposits. The next disengagement zone occurs at a depth of ca. 339 m, where the Miocene sediments are overlain by a about 60-metres thick package of Paleogene deposits dated with the stratigraphically younger pollen and phytoplankton zones D12 of the Upper Eocene and Lower Oligocene (terrestrial facies). These Paleogene deposits were intruded by the Miocene series, a few metres thick, representing pollen zone IX. Then, at a depth of 240 m, occurs the Middle Miocene sedimentary complex, ca. 150 m thick, with pollen zones V, VII and IX. The complicated glacitectonic processes caused such mosaic succession, reflecting the slice structure of glaciotectonic thrust moraines. Palynological studies provided unique data to define the glaciotectonic disengagement zones. The absence of Quaternary deposits in the internal moraine structure indicates the Early Pleistocene age of deformation.
PL
Przedstawiono charakterystykę i wyniki mikrotermometrycznych badań inkluzji fluidalnych występujących w spoiwie skał osadowych wieku od kambru po perm oraz od jury po paleogen i miocen. Inkluzje mają charakter pierwotny i wtórny; na ogół są jedno- lub dwu-, rzadziej trójfazowe. Wypełniają je paleofluidy o zróżnicowanym składzie i różnej gęstości. Temperatura homogenizacji, która stanowi przybliżenie temperatury zamknięcia fluidu w minerale, wykazuje zmienność związaną z rodzajem spoiwa i z historią geologiczną badanego obszaru. Zasolenie fluidów również jest zmienne i zależy od rodzaju spoiwa i od lokalizacji. Połączenie analiz inkluzji np. z badaniami izotopowymi pozwala na szerszą interpretację wyników oznaczeń mikrotermometrycznych.
EN
Characteristics and results of microthermometric studies of fluid inclusions which occur in the cements of sedimentary rocks of the age oscillating form Cambrian to Permian and from Jurassic to Paleogene and Miocene are presented. The inclusions studied are primary and secondary in origin. They display one, two or, less frequently, three phases. The inclusions are filled by the paleofluids of variable compositions and densities. The homogenization temperature, which corresponds to the minimum estimation of the trapping temperature, shows variability in respect to the cement type and geological history of the study area. Salinities of fluids are also variable in respect to the cement type and locality. Wider interpretation of the microthermometric analyses is enabled when they are combined, e.g., with the isotopic studies.
EN
A charophyte gyrogonite assemblage consisting of Platychara cf. sahnii, Nemegtichara grambastii and Microchara sp. is reported herein from two localities (Bara Simla Hill and Chui Hill sections) of the Lameta Formation at Jabalpur. The Lameta Formation locally underlying the Deccan traps has been shown to be pedogenically modified alluvial plain deposits containing one of the most extensive dinosaur nesting sites in the world. They are associated with dinosaur bones and freshwater ostracod assemblages that suggest a Late Cretaceous (Maastrichtian) age. This is the first detailed systematic account of charophyte gyrogonites from the Lameta Formation. This charophyte assemblage is compatible with the biostratigraphic attribution provided by the ostracods. From a biogeographic viewpoint, it exhibits considerable similarity to other infratrappean assemblages of the Nand, Dongargaon, and Dhamni-Pavna sections (Maharashtra), and some intertrappean assemblages of Kora in Gujarat, Rangapur in Andhra Pradesh and Gurmatkal in South India. Globally, the genus Microchara is well distributed throughout Eurasia, whereas the genus Platychara occurs richly in the Upper Cretaceous deposits of Europe, Asia, America and Africa. However, at the specific level, Platychara cf. sahnii shows close affinities with charophytes from the Maastrichtian of Iran whilst Nemegtichara grambastii shows distinct affinities with two species of Early Palaeogene deposits of China and Mongolia. The presence of charophyte gyrogonites in the Lameta sediments is attributed to local lacustrine and palustrine conditions within a flood plain environment.
EN
The succession of the Lechówka section near Chełm in south-eastern Poland presents the first complete record of the Cretaceous–Paleogene (K–Pg) boundary in Poland. Samples of the boundary clay were examined for microtektites and shocked minerals to confirm the impact origin of the sediment. The spheroidal fraction reveals morphological and mineralogical features, e.g., spherules, similar to material from the K–Pg boundary as described from elsewhere. The impact genesis of the spherules is confirmed by the presence of nickel-rich spinel grains on their surfaces. The spinels are considered to be primary microlites and, thus, the spherules at Lechówka can be classified as microkrystites. No shocked minerals were noted. The deposits with spherules comprise Aland Mg-rich smectite (Cheto smectite). This almost pure Mg-rich smectite, forming up to 100% of the clay fraction, derived from the weathering of the impact glass. It is proposed that the spherules isolated from the Cretaceous-Paleogene boundary clay at Lechówka come from the Chicxulub crater in Mexico.
PL
W 40 próbkach pochodzących z czterech formacji paleogeńskich (oligocen) i czterech formacji neogeńskich (miocen) zbadano standardowymi badaniami litopetrograficznymi węglanowość, obtoczenie materiału ziarnistego i skład minerałów ciężkich. Cechy te dobrze charakteryzują analizowane osady i mogą służyć do określania ich pozycji litostratygraficznej. Ma to szczególne znaczenie w badaniach stratygraficznych krótkich odcinków rdzeni wiertniczych, które są głównym materiałem badawczym analizowanych osadów na Niżu Polskim. Formacje morskie oligocenu charakteryzuje podwyższona węglanowość i średnie obtoczenie materiału ziarnistego. Formacje te różnicuje skład minerałów ciężkich. Formacje lądowe oligocenu i miocenu odznaczają się niską węglanowością, na ogół złym stopniem obtoczenia ziaren i znaczną wewnętrzną odmiennością składu i udziału minerałów ciężkich.
EN
The most indicative qualities of four Paleogene formations (Oligocene) and four Neogene formations (Miocene), 40 samples of which have been the subject of the standard lithopetrographic analysis, prove to be carbonate content, grain roundness and composition of heavy minerals. Consequently, on the basis of these features, the lithostratigraphic position of the sediments may be determined, which is of high importance for stratigraphic examinations of short drill core intervals remaining the main research material of the analyzed deposits of the Polish Lowland. Oligocene marine formations are characterized by high carbonate content, medium grain roundness and varying composition of heavy minerals. As far as Oligocene and Miocene continental formations are concerned, low carbonate content and generally angular grains as well as significant differences in the heavy minerals’ composition and percentage may be observed.
EN
The lithostratigraphy and biostratigraphy of the Bystrica/Tylicz and Krynica facies zones of the Magura Nappe have been studied in the Beskid Sadecki Range and Lubovnianska Vrchovina (Polish and Slovak parts of the Western Outer Carpathians respectively). The new, Tylicz Zone is established, and the Szczawnica, Zarzecze, Magura and Kremna formations are redefined and described. These formations, spanning over 35 myrs, represent a synorogenic deep-water turbidites depositional system that dominated the southern part of the Magura Basin after the collision of the Alcapa Mega Unit with the Czorsztyn/Oravic ridge. The calcareous nannoplankton zones NP14-NP25 (Middle Eocene to Late Oligocene) and NN1-NN2 (Early Miocene) were recognized.
EN
Pollen, phytoplankton and microfauna from the Palaeogene and Neogene of two boreholes in NE Poland have been studied. Borehole Klucznik 1 is located in the Warmia area, and borehole Sąpłaty 3 borehole in the Mazury area. The oldest palynomorph assemblage comes from the Klucznik sediments; it consists of phytoplankton from the Early Palaeocene (Danian) D1 and D2 dinocyst zone, and from the Selandian D3 zone. The Eocene is present in the both the Klucznik and the Sąpłaty successions. The Middle Eocene assemblage has been dated as late Bartonian and belongs to the D11 dinocyst zone. The Late Eocene (Priabonian) D12 dinocyst zone is also present in both boreholes. Sporomorphs of a Late Eocene palynomorph assemblage point on the proximity of land and on terrestrial vegetation. The dinocyst zone D13, characteristic for the earliest Oligocene (‘Latdorfian’) has been found in both profiles as well. A Neogene sporomorph assemblage dating from the Middle Miocene (Early Serravallian) occurs only in the Sąpłaty profile. This sporomorph assemblage is correlated with pollen zone VIII. Pollen zone IX is present in the uppermost part of the Middle Miocene (Middle Serravallian). Late Miocene deposits (Late Tortonian) with pollen zone XI are present, too. The Miocene deposits accumulated in densely vegetated swamps, resulting now in the occurrence of lignite. The sedimentary conditions in the Warmia and Mazury regions were identical during the Neogene and Palaeogene, implying that both provinces belonged at the time to one sedimentary basin.
EN
The northern part of theWestern Carpathians suffered polyphase deformation at the boundary between their Central and Outer parts. Palaeostress analysis in the Orava region revealed the existence of five different stress fields in the period from the Late Eocene to the Quaternary. The evolution of the stress fields was determined by detailed structural analysis of the fault slip and fold orientation data. The orientation of the stress fields shows an apparent clockwise rotation from the Late Eocene to the Quaternary. During the Late Eocene to Oligocene, E-W compression and perpendicular tension affected this area. This was the time when the Central Carpathian Palaeogene Basin formed. After this compression, the palaeostress field rotated approximatly 40-50[degrees], and NW-SE compression and NE-SW tension took place in the Early Miocene. The Middle Miocene to Pliocene was characterised by progressive rotation of the palaeostress field from NW-SE to the NE-SW direction of the maximum principal compressional stress axis ([sigma][1]). This clockwise rotation of the Oligocene to Quaternary palaeostress fields here is explained by the effect of the counterclockwise rotation of the ALCAPA microplate, and by the regional stress field changes in this region. The Quaternary stress field was reconstructed on the basis of structural measurements in the Pliocene sedimentary formations of the Orava-Nowy Targ Basin. The results of the palaeostress analysis show that the Quaternary stress field is characterised by E-W-oriented S[h] (minimum horizontal compression) and N-S-oriented S[H] (maximum horizontal compression).
first rewind previous Strona / 2 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.