1,274 research outputs found

    Nuova classificazione biostratigrafica e geocronologica delle unità formazionali oligoceniche e neogeniche della Sardegna. Correlazioni con le omologhe unità della Corsica

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    Recent revisions in classification and the new definitions in the literature of late Paleogenic and Neogenic formations outcropping in the northern, central and southern Sardinia provided by the authors have led to the preparation of a complete biostratigraphic and geochronological picture of the entire Sardinian Tertiary sedimentay basin. The lithostratigraphic units, of which the measured stratigraphic sections of reference will be given in another work, were placed in the most recent and up-to-date zonal classifications of Mediterranean planktonic Foraminifers associations and calcareous plankton. In this proposal for the reclassification of the stratigraphic successions of Sardinia’s Oligocene-Neogene, three main marine sedimentation cycles are recognized. These are silicoclastics and mixed silicoclastic-carbonatic sediments, sometimes richly fossiliferous, in which are inserted volcanic products going from acid to intermediate-basic and having a calcalkaline composition (the «Oligo-Miocene volcanic cycle») almost exclusively in the Aquitanian-Late Burdigalian interval. On the basis of a comparative analysis of autochthonous benthic associations, especially those with molluscs and of the textural characteristics of the sediments, the prevalent depositional environment is that of a platform and secondly of a slope, but in some cases fluvio-lacustrine and deltaic (preliminary data on the paleo-ecological aspects are being prepared for publication). Of the three main sedimentation cycles, the first evolved between the Chattian-Aquitanian limit and the Late Burdigalian (N6 Zone); the second cycle began in the Uppermost Burdigalian, in correspondence to the upper part of the Globigerinoides trilobus Zone (N7 Zone) and closes in the Late Serravallian (G. siakensis Zone, G. siakensis - G. obliqua obliqua Subzone); finally, the third cycle begins in the Uppermost Serravallian and finishes in the Early Messinian, in correspondence to the upper part of biostratigraphic N17a Zone. The successions examined are also considered with reference to the major tectonic and volcanic events which took place in Sardinia from the Oligocene to the Pliocene within the wider context of the geodynamic evolution of the western Mediterranean area. In particular, the first two sedimentary cycles which evolved from the end of the Oligocene and the Early-Middle Miocene would appear to be closely connected with the collision and postcollision phases respectively of the northern Apennines. The northern Apennines collision phase appears to have manifested itself in Sardinia with an important transcurrent tectonic with transpressive and transtensive structures and with the development of subsidence basins of the pull-apart type in correspondence to which the first Miocene sedimentary cycle and the associated calcalkaline volcanism developed. The creation in the Burdigalian of the wide N-S Sardinian rift, in which the second Miocene sedimentary cycle evolved, is to be attributed to the subsequent phase of postcollision distension. The third Miocene sedimentary cycle becomes manifest, following a regressive phase, limited to the most subsident areas of the Logudoro -Sassari, Capo Frasca - Sinis and Cagliari regions. The marine ingression of the Early Pliocene, located in central Sardinia (Cava Fuile and Nuraghe Baboe Cabitza B nn. Formations) and in the south of the island (in drilling) is to be placed in connection with the strong resumption of the southern Tyrrhenian distensive tectonics towards the end of the Messinian and Pliocene, as well as with widespread alkaline, prevalently basaltic, volcanic activity (the «Plio-Pleistocene volcanic cycle»). In the Late-Middle Pliocene, between the Gulf of Cagliari and the Gulf of Oristano, there was the development of the Campidano graben, filled with more than 500 m of continental deposits (the Samassi Formation). The four Corsican basins (Bonifacio, Saint Florent, Francardo, the eastern Plain), in which Miocene and/or Pliocene sediments outcrop, show, starting from the summital Burdigalian, an evolution that is fairly parallel to what has been recognized in the north of Sardinia. The formations of Aghione, Saint Florent, Cala di Labra and Bonifacio are in fact partly referable to the second Sardinian sedimentary cycle. The subsequent phases characterized in Corsica by emersion, marine sedimentation (the Vadina and Urbino units), fluvio-deltaic sedimentation (the Aleria Formation) and further marine sedimentation (the Urbino, Casabianda, Propiano and Aiaccio units), are in Sardinia respectively correlated with the hiatus and/or erosion or continental sedimentation in the Late Serravillian, with the Tortonian part of the third marine sedimentation cycle (the Monte San Michele Formation), with the Messinian part of the same cycle (the Capo San Marco, Sinis and Torre del Sevo Formations) and with the Nuraghe Baboe Cabitza B (Capo San Marco) Pliocene formation

    THE "GERMANIC" TRIASSIC OF SARDINIA (ITALY): A STRATIGRAPHIC, DEPOSITIONAL AND PALAEOGEOGRAPHIC REVIEW

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    The collection of new lithostratigraphical and sedimentological data has allowed to re-examine the Triassic sedimentation cycle in Sardinia The most important outcrops have been revisited and their general setting reinterpreted. A detailed and homogeneous depositional, palaeoenvironmental and stratigraphic picture is proposed, pointing to the analogies with both the typical Germanic Triassic of Central Europe, and the Middle Triassic Sephardic domain of Western Europe and North Africa. The lower, essentially siliciclastic, lithostratigraphic units, resting discordantly on the Hercynian Palaeozoic basement, resemble the "Buntsandstein" facies association. They are generally of Anisian age. Their depositional environments range from high-energy continental to transitional environments to the floodplain, where a shallow, epicontinental sea gradually transgressed. Overlaying these are the carbonate units of the "Muschelkalk" facies association. They are generally dolomitic at the bottom passing to calcareous at the top. These deposits, generally of Ladinian age, formed in the various subenvironments of a carbonate ramp. The few Upper Triassic successions in Sardinia point to the existence, during this period, of diverse depositional conditions in the North (Nurra) and South (Sulcis) of the island. In southern Sardinia, lagoon to shallow sea carbonate shelf deposition predominates, with minor amounts of evaporites and siliciclastics. By contrast, in Northern Sardinia mixed evaporitic-siliciclastic-carbonate facies of paralic-continental (mudflat), locally restricted lagoonal environments, were deposited. The latter are very similar to the classic Germanic "Keuper" facies. These data suggest that the Upper Triassic successions in Southern Sardinia can be set in a transitional environmental context between the open Alpine-Tethyan domain and the Germanic Triassic proper. An attempt has been made to correlate these successions with the Middle to Late Triassic eustatic cycles.&nbsp

    Ridefinizione biostratigrafica e geocronologica delle unità formazionali neogeniche della Sardegna centrale (Italia)

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    Recent, detailed geological and stratigraphic surveys of a large area of the Marmilla region (central Sardinia) have made it possible to reconsider the lithobiostratigraphic characteristics of the formal and informal units in the literature on the Cenozoic (Late Oligocene – Neogene) which have been in use up to now. Extension of the research to adjoining lands, including Alta Marmilla, Alto Oristanese, Sinis–Planargia, Barigadu, Baronie and Sarcidano, has also made it possible to perform an overall analysis of the entire Cenozoic basin of central Sardinia and, finally, to make significant comparisons with the coeval successions outcropping in southern and northern Sardinia. In this preliminary note we then report on new data concerning the biostratigraphic aspects of the successions considered, while eco-biostratigraphic data and the depositional and synthemic arrangement, now at an advanced stage of definition, will be discussed in a later, more complete work. Some units in the literature are once again proposed, albeit with amendments, as suggested by the new regulations governing the establishment of new formal depositional units and conservation of units in the literature, and with new geochronostratigraphic delimitations (e. g. the Gesturi Formation). Other units change their hierarchical rank (e. g. the Marmilla Group), while for others it was not deemed useful to keep them (e. g. Marne di Ales), since they might cause confusion. Most of the Formations, all of the Members and Groups are proposed in this work for the first time. The formation units outcropping in central Sardinia’s Cenozioc basin are represented for the most part by a sedimentary and volcano-sedimentary succession several hundreds of metres thick, the age of which is included within the Chattian-Aquitanian passage and the Plio-Quaternary. These are sediments from silicoclastics to mixed carbonatic-silicoclastics, in some cases richly fossiliferous, in which are inserted volcanic products from acid to intermediate-basic with a calcalkaline composition, the latter almost exclusively present starting from the Aquitanian up to the Late Burdigalian, with the strongest concentration in deposits of Burdigalian age. As is the case in northern and southern Sardinia, central Sardinia’s Miocene formations can be referred to three main sedimentary cycles recognized on the basis of heir litho-biostratigraphy and the analysis of associations of benthic macrofauna, which will be discussed in a specific article to be published shortly. The first Miocene sedimentary cycle evolved between the Chattian/Aquitanian limit and the Late Burdigalian (N6 Zone); the second cycle began in the Uppermost Burdigalian, in correspondence to the upper part of the Globigerinoides trilobus Zone (N7 Zone) and closes in the Late Serravallian (G. siakensis Zone, G. siakensis-G. obliqua obliqua Subzone); finally, after a clear regression phase, in the Tortonian (or perhaps already in the Uppermost Serravillian) the third cycle began and ended in the Early Messinian, in correspondence to the upper part of biostratigraphic N17a Zone. On the basis of a comparative analysis of autochthonous benthic associations, especially those with molluscs, and of the textural characteristics of the sediments, the prevalent depositional environment for the three cycles mentioned previously is that of a platform and secondly of a slope, but in some cases fluvio-lacustrine and deltaic. At the end of the third cycle there is a hiatus and/or erosion, or local continental sedimentation (Nuraghe Baboe Cabitza A n. Formation). A further marine sedimentary cycle locally (Sinis, Orosei) began and ends in the Lower Pliocene (Nuraghe Baboe Cabitza B n. Formation). In an overall biostratigraphic and geochronological frame, the comparison between the most important sedimentary, tectonic and volcanic occurrences in central Sardinia from the Oligocene to the Pliocene and those which occurred in the north and south of the island are pointed out. From the paleogeographic standpoint, the deposits of the first Miocene sedimentary cycle are part of the autochthonous cover of the southern European continental margin; those of the second and third cycles are instead connected with the aperture of the Balearic basin and the northern Tyrrhenian Sea; finally, the Early Pliocene marine succession is referred to the open of the southern Tyrrhenian basin, as well as the widespread volcanic activity of prevalently basaltic alkaline nature (the «Plio-Pleistocene volcanic cycle») towards the end of the Messinian and in the Pliocene

    CONODONT BIOSTRATIGRAPHY OF THE "OCKERKALK" (SILURIAN) FROM SOUTHEASTERN SARDINIA

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    Twenty-two conodont species are recognized in the Ockerkalk exposed in the Silius area (Gerrei, southeastern Sardinia). The fauna, which is the first reported from this peculiar facies, indicates a Ludlow and e.-m. Pridoli age for this limestone. Three conodont biozones (latialata, snajdri and crispa) are reported for the first time in Sardinia and, the Pelekysgnathus index horizon is newly recovered in Europe

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good
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