27 research outputs found

    F-term uplifting via consistent D-terms

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    The issue of fine-tuning necessary to achieve satisfactory degree of hierarchy between moduli masses, the gravitino mass and the scale of the cosmological constant has been revisited in the context of supergravities with consistent D-terms. We have studied (extended) racetrack models where supersymmetry breaking and moduli stabilisation cannot be separated from each other. We show that even in such cases the realistic hierarchy can be achieved on the expense of a single fine-tuning. The presence of two condensates changes the role of the constant term in the superpotential, W_0, and solutions with small vacuum energy and large gravitino mass can be found even for very small values of W_0. Models where D-terms are allowed to vanish at finite vevs of moduli fields - denoted `cancellable' D-terms - and the ones where D-terms may vanish only at infinite vevs of some moduli - denoted `non-cancellable' - differ markedly in their properties. It turns out that the tuning with respect to the Planck scale required in the case of cancellable D-terms is much weaker than in the case of non-cancellable ones. We have shown that, against intuition, a vanishing D-term can trigger F-term uplifting of the vacuum energy due to the stringent constraint it imposes on vacuum expectation values of charged fields. Finally we note that our models only rely on two dimensionful parameters: M_P and W_0.Comment: 10 pages, 2 figures, plain Latex, references adde

    Relief dna morskiego a zróżnicowana kompakcja w kopalnych platformach węglanowych: krytyczne przeszacowanie przykładu z górnej jury Wyżyny Krakowsko-Wieluńskie

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    The growth of carbonate buildups in the northern, stable shelf of the Tethyan Ocean was the principal factor in the development of diversified sea-bottom relief in the Late Jurassic basin. Reconstruction of this relief has been a matter of numerous controversies. This paper provides an analysis of published data on elevation differences on sea bottom along the SW margin of the Holy Cross Mts. and in the Cracow-Wielun Upland. Moreover, methods of reconstruction of synsedimentary relief are presented. In the Late Oxfordian the elevations on basin floor in the Czestochowa area (Cracow-Wielun Upland) were about 100 meters at most, and were presumably even lower. The largest (over 200 meters) elevation differences of sea-bottom relief existing in the Czestochowa area at the Oxfordian/Kimmeridgian have been postulated when the recently observed differences in thickness between the deposits of carbonate buildup and of equivalent basinal facies were identified as a relief. In fact, different thickness is, in considerable part, an effect of differential compaction.Wzrost budowli węglanowych na północnym, stabilnym szelfie Tetydy był główną przyczyną powstania urozmaiconego reliefu dna w basenie późnojurajskim. Rekonstrukcja tego reliefu jest przedmiotem licznych kontrowersji. Praca analizuje dane literaturowe o wielkości deniwelacji dna z rejonu SW-obrzeżenia Gór Świętokrzyskich i Wyżyny Krakowsko-Wieluńskiej oraz omawia metodykę rekonstrukcji reliefu synsedymentacyjnego. Deniwelacje dna basenu u schyłku oksfordu w rejonie Częstochowy wynosiły co najwyżej około 100 m a przypuszczalnie były jeszcze mniejsze. Postulowane wcześniej, ponad dwustumetrowe deniwelacje w basenie w rejonie Częstochowy na przełomie oksfordu i kimerydu były oparte na utożsamianiu z deniwelacjami dna aktualnej różnicy miąższości między utworami budowli węglanowej a ekwiwalentnymi jej utworami facji basenowej. Różnica ta jest w znacznej części wynikiem zróżnicowanej podatności osadów na kompakcję

    Experimental method for estimation of compaction in the Oxfordian bedded limestones of the southern Kraków-Częstochowa Upland, Southern Poland

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    The Upper Jurassic carbonates exposed in the southern part of the Kraków-Częstochowa Upland are well known for their significant facies diversity related to the presence of microbial and microbial-sponge carbonate buildups and bedded detrital limestone in between. Both the buildups and detrital limestones revealed differential susceptibility to compaction which, apart from differential subsidence of the Palaeozoic basement and synsedimentary faulting, was one of the factors controlling seafloor palaeorelief in the Late Jurassic sedimentary basin. The compaction of the detrital limestones has been estimated with an experimental oedometric method in which specially prepared mixtures made of ground limestones from a quarry in the village of Żary were subjected to oedometer tests. The diameters of the detrital grains and their percentages in the limestones were determined by microscopic examinations of thin sections. The diameters were assigned to predetermined classes corresponding to the Udden-Wentworth scale. The rock samples were then ground down to the grain sizes observed in thin sections. From such materials, mixtures were prepared of grain size distributions corresponding to those observed in thin sections. After adding water the mixtures were subjected to oedometer tests. Analysis of the compression of such mixtures under specific loads enabled preparation of a mathematical formula suitable for the estimation of mechanical compaction of the limestone. The obtained values varied from 27.52 to 55.53% for a load corresponding to 300 metres burial depth. The most significant effect of mechanical compaction was observed for loads representing only 2 metres burial depth. Further loading resulted in a much smaller reduction in sample height. The results of the oedometer tests cannot be used directly to determine compaction of the detrital limestones. Mainly because microscopic observations of thin sections of the experimental material show that chemical compaction was also an important factor influencing thickness reduction of the limestones

    Microbial laminites with coprolites from Upper Jurassic carbonate buildups (Kraków-Częstochowa Upland, Poland)

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    The Upper Oxfordian microbial-sponge agglutinated to open-frame reef complex of the Zegarowe Crags in the Kraków-Częstochowa Upland originated upon an elevation of the Late Jurassic stable northern shelf of the Tethys. This elevation was formed, owing to a local decrease in subsidence rate during Jurassic time, induced by the presence of a Palaeozoic granitoid intrusion in the shelf substratum, and Late Jurassic, synsedimentary tectonics, which controlled the topography of the sea bottom. The Zegarowe Crags (Skały Zegarowe) complex at the top contains microbial laminites, composed of peloidal and agglutinated stromatolites, and intercalations of grainstones with indeterminable, favrenoid coprolites, occurring in large numbers. The development of stromatolites was associated with low nutrient availability. In contrast, the periodic activity of crabs, the main producers of the coprolites, forming the coprolitic grainstone intercalations, indicates periods, when nutrients were abundant in the sea water. The nutrinets most likely were associated with the occurrence of clouds of suspended matter, induced by gravity flows, generated by active, synsedimentary tectonics. The results of isotopic studies do not support the presence of warm, mineralizing solutions, connected with synsedimentary tectonics during development of the Zegarowe Crags complex in the Late Jurassic

    Pressure dissolution features in Oxfordian microbial-sponge buildups with pseudonodular texture, Kraków Upland, Poland

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    Part of the Oxfordian carbonate buildups in the southern part of the Kraków Upland is developed as pseudonodular limestones, which represent segment reefs. These limestones are composed of connected, rounded-oval to subangular carbonate pseudonodules. The pseudonodules, densely packed within the limestone, fall out easily under mechanical stress. The recently observed texture of pseudonodular limestones resulted from two stages of chemical compaction. During the first stage, in the Late Jurassic, high-amplitude and low-amplitude stylolites and dissolution seams were formed. The sites particularly favourable for the development of high-amplitude stylolites were the boundaries between already lithified fragments of the laminar, rigid microbial-sponge framework. The low-amplitude stylolites formed mainly in the intercalated wackestone-packstone, which was lithified somewhat later; hence, the dissolution seams originated at the contacts between the rigid microbial-sponge framework and the wackestonepackstone. After Early Cretaceous erosion, which decreased the burial load, Late Cretaceous sedimentation enabled the renewal of pressure dissolution. Thus, some low-amplitude stylolites evolved into dissolution seams. In stylolites composed of both low- and high-amplitude segments, dissolution proceeded at the bases of interpenetrating high-amplitude stylolite columns, with the simultaneous transformation of low-amplitude stylolite segments into dissolution seams. These seams, which formed at the initial stage of chemical compaction, were subjected in turn to further pressure dissolution, giving rise to the formation of horsetail structures. The vertical stress field, which triggered the pressure dissolution processes, presumably resulted in the formation of high-angle and vertical incipient tension gashes. At the beginning of the processes, these gashes remained closed. In the Cenozoic, under the extensional regime generated by overthrusting Carpathian flysch nappes, some high-angle and vertical dissolution seams and low-amplitude stylolites opened up, forming deformed dissolution seams and deformed stylolites. Under the same conditions, the high-angle and vertical tension gashes opened up as well. Subsequently, during the exposure period, unloading fractures developed, partly as a result of the opening of some subhorizontal and horizontal dissolution seams and stylolites. The unloading fractures, along with the already existing vertical and high-angle tension gashes, formed the network changing the limestone into pseudonodules of various shapes and sizes. The open spaces between the limestone fragments became local conduits for karst waters

    Experimental method for estimation of compaction in the Oxfordian bedded limestones of the southern Kraków-Częstochowa Upland, Southern Poland

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    The Upper Jurassic carbonates exposed in the southern part of the Kraków-Częstochowa Upland are well known for their significant facies diversity related to the presence of microbial and microbial-sponge carbonate buildups and bedded detrital limestone in between. Both the buildups and detrital limestones revealed differential susceptibility to compaction which, apart from differential subsidence of the Palaeozoic basement and synsedimentary faulting, was one of the factors controlling seafloor palaeorelief in the Late Jurassic sedimentary basin. The compaction of the detrital limestones has been estimated with an experimental oedometric method in which specially prepared mixtures made of ground limestones from a quarry in the village of Żary were subjected to oedometer tests. The diameters of the detrital grains and their percentages in the limestones were determined by microscopic examinations of thin sections. The diameters were assigned to predetermined classes corresponding to the Udden-Wentworth scale. The rock samples were then ground down to the grain sizes observed in thin sections. From such materials, mixtures were prepared of grain size distributions corresponding to those observed in thin sections. After adding water the mixtures were subjected to oedometer tests. Analysis of the compression of such mixtures under specific loads enabled preparation of a mathematical formula suitable for the estimation of mechanical compaction of the limestone. The obtained values varied from 27.52 to 55.53% for a load corresponding to 300 metres burial depth. The most significant effect of mechanical compaction was observed for loads representing only 2 metres burial depth. Further loading resulted in a much smaller reduction in sample height. The results of the oedometer tests cannot be used directly to determine compaction of the detrital limestones. Mainly because microscopic observations of thin sections of the experimental material show that chemical compaction was also an important factor influencing thickness reduction of the limestones

    Teaching of geological mapping at Geological Mapping Department, AGH University of Science and Technology, Kraków

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    This paper presents the methods and scope of teaching geological mapping at the Geological Mapping Department, Faculty of Geology, Geophysics and Environments Protection, Stanisław Staszic AGH University of Science and Technology. The main curriculum of Structural Geology and Geological Mapping consists of lectures, laboratory exercises and a summer field practice in Poland, Croatia, Slovakia or Ukraine. Teaching of geological mapping is linked to research done by the staff and to the content of the course Geomorphology and Quaternary Geology (geomorphological mapping). Students have been also taught practical use of the GPS (Global Positioning System)

    Porównanie górnojurajsko-kredowych utworów epikontynentalnych południowej Polski i południowo-zachodniej Ukrainy na podstawie analizy płytek cienkich

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    Detailed micropaleontological investigation of more than 400 samples (150 identified species) from the Mesozoic sediments of southern Poland and southwestern Ukraine was the basis for their correlation. The youngest Mesozoic assemblage identified in the studied material represent the early Late Cretaceous (Turonian). This assemblage occurs in the so-called the III Formation of Turonian epicontinental strata in Poland, and in the Dubivtsi Formation in West Ukraine. Microfossil assemblages of the Early Cretaceous age (Berriasian–Barremian) allow for a correlation of the Ropczyce and Dębica formations (central part of S Poland) and the upper part of the Babczyn and Cieszanów formations (SE Poland) with the Stavchany Formation and a part of the Bukovyna Formation in SW Ukraine. Tithonian microfossil assemblages from Poland resemble those of the shallow-water Nyzhniv Formation from the Ukrainian part of the East European Platform. Open-marine microfossils (e.g. calpionellids) commonly occur only in the Ukrainian material. Poor microfossil assemblages of the Kimmeridgian age occur in majority of studied subdivisions. They were identified in the Sobków Formation and the upper part of the Niwki Formation in the central part of S Poland, Ruda Lubycka, the upper part of the Bełżyce, Basznia, and Głowaczów formations (SE Poland) and in the Moryantsi and Pidluby formations (Bilche-Volitsia zone of the Carpathian Foredeep) and in the Rava Rus’ska Formation (Eastern European Platform). Among the Oxfordian microfossil assemblages, only those containing Alveosepta jaccardi (Schrodt) and Protomarssonella jurassica (Mityanina) allow for a correlation of subdivisions from both areas. These assemblages occur in the “Coral-algal” Formation in the Tarnów–Dębica region and in the Bełżyce, Jasieniec and Jarczów formations in SE Poland. The coeval sediments belong to the Boniv, Rudky and Sokal formations in West Ukraine. Scarce data from the Middle Jurassic sediments do not allow for a correlation of the material studied.Szczegółowa analiza mikropaleontologiczna ponad 400 próbek (150 oznaczonych gatunków) z utworów mezozoicznych południowej Polski i zachodniej Ukrainy umożliwiła korelację tych utworów. Najmłodsze stwierdzone, w badanym materiale, zespoły reprezentują niższą późną kredę (turon). Zespół ten występuje w tzw. III formacji utworów epikontynentalnych w Polsce oraz w formacji dubowieckiej SW Ukrainy. Zespoły mikroskamieniałości wieku wczesnej kredy (berias–barrem) pozwalają na korelację formacji z Ropczyc i Dębicy (centralna część Polski południowej) oraz górnej części formacji z Babczyna i formacji cieszanowskiej (SE Polska) z formacją stawczańską i częścią formacji bukowińskiej SW Ukrainy. Stwierdzone w materiale z Polski zespoły mikroskamieniałości tytonu przypominają zespoły z płytkowodnych utworów formacji niżniowskiej ukraińskiej części platformy wschodnioeuropejskiej. Natomiast większość zespołów mikroskamieniałości tytonu z badanych utworów SW Ukrainy charakteryzuje obecność form otwartego morza (kalpionellidów). Zespoły mikroskamieniałości kimerydu, choć ubogie,występują w większości badanych utworów. Stwierdzono je w formacji z Sobkowa i w górnej części formacji z Niwek (centralna część Polski południowej) w formacji z Rudy Lubyckiej oraz w górnych częściach formacji bełżyckiej, z Baszni, głowaczowskiej (SE Polska), a także na Ukrainie w formacjach moranieckiej i podlubieckiej (strefa Bilcze-Wolica zapadliska przedkarpackiego) i w formacji z Rawy Ruskiej (platforma wschodnioeuropejska). Z zespołów oksfordu jedynie te, które zawierały otwornice Alveosepta jaccardi (Schrodt) i Protomarssonella jurassica (Mityanina), pozwalają na korelację badanych wydzieleń litostratygraficznych. Zespoły takie występują w formacji „koralowcowo-glonowej” rejonu Tarnów–Dębica (centralna część Polski południowej) oraz w formacjach bełżyckiej, jasienieckiej i jarczowskiej (SE Polska). Na obszarze SW Ukrainy do równowiekowych utworów należą formacje: boniwska, rudkowska i sokalska. Niedostateczna ilość danych mikropaleontologicznych z utworów jury środkowej nie pozwoliła na wykonanie korelacji
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