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  • The surroundings and the age of the upper paleolithic site on Susak island
    214-222
    Views:
    137

    Our study investigates the paleoenvironmental conditions of an Upper Paleolithic site found in the excavation of the North Adriatic Susak Island. Our research explores the range of the loess and loesslike sediments deposited on rudist limestone which is the substratum of the island. We studied the Quaternary sediments by a coherent paleoenvironmental assessment method. The geomorphological and the various chronological analysis contribute significantly to the extension of our knowledge on the paleoenvironmental conditions of the Upper Paleolithic site (Radiocarbon age is 31,830 ±720 yr BP) on Susak Island.

  • Morphological grouping of fossil floodplain forms in the northeastern part of the Pannonian plain
    21-33
    Views:
    26

    The Bereg Plain is located in the northeastern part of the Pannonian Plain, close to the Carpathian
    Mountains. Clarification of the evolution of its topography is essential for the development of the whole
    area. The former single alluvial cone has been fragmented, some parts of it subsiding and others rising.
    The displacements of the subsided parts of the area were dominated by erosion processes, as in the Bereg
    Plain. As a consequence, a significant part of the sand in the area has been degraded and only traces of it
    remain in the Bereg Plain. The existing sand patches have been identified and classified using DEM. In the
    area identified 10 floodplain islands not yet mentioned in the scientific literature. The investigation of
    the numerous islands – hitherto unknown and be-longing to different morphological types – enabled us a
    reconstruction of the surface development of the Bereg Plain that is more differentiated and precise than
    ever before. Based on their morphogenetic properties, these floodplain islands can be divided into three
    main types: (1) erosion islands, (2) point-bars, (3) coastal dunes. In the area, I could recognize no pattern
    or re-gularity in the position of the individual forms of any type. In many cases, the direction of the
    longitudinal trends is perpendicular to one another, which excludes their Aeolian origin. The sediment
    of the floodplain islands mainly consists of medium-, small- and fine-sized sand, but the settlement of
    loess-mantled and loess-like layers among the sandy sediment of certain forms can also be observed. The
    layer with 15 % lime content and 53–60 % loess fraction (0.05–0.01 mm) – found in the 110–50 cm high
    section of the erosion island called the Homok-tanya in Mátyus – can be considered a typical loess, based
    on the detailed parameters. Its formation in all probability took place at the same time and under similar
    conditions than that of the more than 2 m thick aeolian loess mantle found in the Nyírség area, some 10
    km west from there, which had accumulated before the Bölling period. In case of an erosion island 2.5
    km to the south and lying some 2 m lower, such a loess mantle cannot be found anymore, despite the fact
    that the sandy layers of the two sediment series are almost completely identical. The background of this
    phenomenon is the more active and frequent, mainly erosional fluvial processes – because of the lower
    position –, which eroded the loess mantle.
    The composition of the surface sediments is de-termined by the absolute altitude as well. The cover
    sediment of the lower-lying islands is identical to the finishing silt-clay deposits found at the alluvial
    parts of the Bereg Plain, whereas the surface of higher-lying forms that have not seen flood for ages, is
    covered by sand or loessy sand.

  • Paleoenvironments reconstructed from the analyses of loess sequences on Susak Island, Adriatic Sea
    1-9
    Views:
    129

    Susak Island is the outermost member of the archipelago of the Kvarner Bay, North Adriatic Sea, Croatia. Its long-term landscape evolution is defined by tectonic movements. Most characteristic are partly exhumed landforms of an ancient terrane (scarps, uplifted limestone cliffs) in a still active neotectonic environment, but the most appropriate tools for the reconstruction of Quaternary paleoenvironments are loess and loess-like deposits. The Quaternary sequence is up to almost 100 m thickness locally and intensively studied by numerous disciplines (from structural geology to geochemistry and geomorphology) today. The special location of the island makes it a key area of research into the evolution of the broader environment, including the Po Plain as well as other Italian source areas of wind-borne and redeposited dust. The loess mantle was also of great importance for a paleoecological reconstruction of floral and faunal evolution, on which efforts of nature conservation are founded.

  • Mount Pele, an ecoclimatic gradient generator
    27-41
    Views:
    67

    Generally, mountains determine the characteristics of particular areas, because of the island phenomenon they cause. However, the geological origins of mountains are multiple and they are located in different climatic regions. Nevertheless, in all aspects they reflect the basic elements of the local biologic unit. The shapes, climates, diverse water resources, biocenoses and the generated soils are the different components that determine, through their dynamic interaction, the “Mountain” ecosystem. Tectonic subduction processes lead to the development of islands such as Martinique, whose basic structure consists of a series of mountains (among them Mount Pele). Like the topographic divisions, the local micro-climates, water courses, different soils (themselves the consequences of the presence of the mountain itself) and successive volcanic eruptions determine, over time, the organization of the diverse vegetal entities.

  • Morphological alteration of the Dráva as the result of human impact
    58-75
    Views:
    87

    The Croatian-Hungarian border section of the Dráva River has been undisturbed for almost a century, and it is characterised by unique fluvial morphology (braided pattern and islands) supporting rich habitats and wildlife. However, during the last decades human impact became more and more intensive. Between 1975 and 1989 three water reservoirs were built on the Croatian section of the river, just 16 km from the beginning of the border-section, altering the hydrology and the sediment characteristics of the river. On a local scale cut-offs, revetments and groynes were built. The aim of the study was to evaluate the effect of these human interventions. As the result of the alteration of the hydrology the channel pattern of the Dráva has been changing from braided to meandering, though on the upstream meandering part the territory and number of islands increased due to the drop of water stages. A cut-off and a groyne influenced only the morphology of a short section. As the result of the cut-off braided pattern became more pronounced, and the groyne caused intensive channel aggradation and gave way to lateral island development.

  • Boundless settlements – tendencies and future of urban sprawl in the agglomeration of Budapest
    75-88
    Views:
    182

    The Budapest agglomeration is a rapidly changing environment. Urban sprawl has been a prominent process in municipalities around the Hungarian capital, and its pace has significantly increased since the change of regimes. In our paper, we analyse the tendencies of urban development, the role of territorial protection and the types of land use mostly threatened by urban sprawl in two study areas within the Budapest agglomeration. A significant part of the Northern study area – located on Szentendre Island – is under territorial protection, while the Southern study area – located on Csepel Island – has a considerably lower amount of protected areas. We found that the settlements of the Northern study area have been expanding at a much slower pace than their Southern counterparts, where in the absence of effective restrictions, extensive areas – mostly former agricultural fields – have been converted into built-up areas. In addition, the Spatial Plan of the agglomeration allows the same tendencies to continue in both areas in the future as well.