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Résultats de la recherche (219 résultats)

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  • The Maiella Escarpment (Abulia platform, Italy) : geology and modeling of an Upper Cretaceous scalloped erosional platform margin
  • Appennino ; Cretaceous ; Erosion ; Escarpment ; Italy ; Model ; Palaeogeography ; Platform ; Regional geology
  • This report focuses on one of the most debated features of the Maiella geology, i.e. the paleoescarpement a ca. 1000 m high erosional surface abruptly separating Cretaceous slope from platform facies. The attempt has been to address some crucial
  • questions such as the reconstruction of a morphologic model applicable to the entire exhumed portion of the Maiella escarpment, and to investigate the relationships between the paleoescarpment morphology and mechanisms responsible for the platform margin
  • Modelling the effect of waves, weathering and beach development on shore platform development
  • Cliff ; Coastal dynamics ; Coastal environment ; Erosion ; Mathematical model ; Model ; Shore platform ; Tide ; Wave
  • A mathematical model was used to study shore platform development. In addition to mechanical wave erosion, this model considers the effect of a number of other important factors, including platform downwearing by weathering, the abrasive
  • and protective effects of beach sediment accumulation, and variable cliff height and debris mobility. The primary goal of this study was to examine how these interacting factors influence the development of shore platforms in different environments, rather than
  • to replicate the morphology of platforms after specific periods of time.
  • Lacustrine shore platforms at Lake Waikaremoana, North Island, New Zealand
  • Comparative study ; Erosion rate ; Lacustrine sediment ; Lake ; Lake level ; Model ; New Zealand ; North Island ; Ocean ; Shore platform ; Weathering
  • This paper has 3 objectives. First, to describe the shore platforms at Lake Waikaremoana. Second, to determine whether principles governing oceanic platforms can be applied to a lacustrine setting, and third to present a conceptual model
  • for the development of the shore platforms at Lake Waikaremoana.
  • Granite platforms and low domes : newly exposed compartments or degraded remnants?
  • Field observations of infragravity waves and their behaviour on rock shore platforms
  • Cliff ; Coastal dynamics ; Coastal environment ; Coastal erosion ; New Zealand ; North Island ; Sea level ; Shore platform ; Wave
  • Infragravity wave (IGW) transformation was quantified from field measurements on 2 shore platforms on New Zealand's east coast (Oraka and Rothesay Bay). The observed increase in IGW height over the platform during both experiments is attributed
  • to shoaling. The proportional increase in IGW height shows a strong correlation to water level on each platform. The rate of shoaling of long period waves on the shallow, horizontal platforms increased at higher water levels resulting in a super elevation
  • in water level at the cliff toe during high tide. Results from this study show the first measurements of IGWs on shore platforms and identify long wave motion a significant process in a morphodynamic understanding of rock coast.
  • Shore platform morphology on a rapidly uplifting coast, Wellington, New Zealand
  • Coastal environment ; Coastal erosion ; Coastal geomorphology ; Marine abrasion ; New Zealand ; North Island ; Shore platform ; Tectonics ; Vertical movement
  • The coast of Wellington is tectonically active and contains a series of uplifted and contemporary shore platforms that are developed in Triassic Greywacke. The rate of development of these platforms is rapid. The co-seismic uplift means
  • that the rear of the platforms is raised beyond the limits of marine process and has become an area of deposition. Although no direct process measurements were made the highly fractured nature of the bedrock appears to play a major role in platform evolution
  • , with wave processes being easily able to pluck blocks as evidenced by fresh erosion scars and active gravel beaches at the rear of many platforms.
  • A Pleistocene origin for shore platforms along the northern Illawara coast, New South Wales
  • Aminostratigraphy ; Australia ; Coastal sedimentation ; Dating ; New South Wales ; Pleistocene ; Quaternary ; Sea level ; Shore platform ; Shoreline ; Thermoluminescence ; Tsunami
  • This paper examines the composition, structure and age of clastic deposits situated behind shore platforms at Austinmer and Coledale on the northern Illawara coast, New South Wales. The results support earlier chronological evidence of a Pleistocene
  • history for shore platforms along the Illawara coast.
  • Lithological control on the elevation of shore platforms in a microtidal setting
  • This paper describes shore platforms around Shag Point on the eastern coast of South Island, New Zealand. The interesting feature of these platforms is that within a very limited distance their elevation changes from supratidal to low tide level
  • . The local geology of Shag Point is described and a hypothesis put forward to account for the form of the platform at this location.
  • Shore platform abrasion in a para-periglacial environment, Galicia, northwestern Spain
  • Coastal environment ; Galicia ; Holocene ; Inherited features ; Marine abrasion ; Periglacial features ; Shore platform ; Spain ; Weathering
  • This paper uses surface rock hardness variations to identify present and past abrasional activity on shore platforms in northwestern Spain, and to show how spatial and temporal in abrasion efficacy have resulted from the exhumation and inheritance
  • of ancient platform surfaces from beneath Weichselian deposits.
  • Defining shore platform boundaries using airborne laser scan data : a preliminary investigation
  • Coastal environment ; Digital elevation model ; Geographical information system ; Methodology ; New Zealand ; Remote sensing ; Shore platform ; South Island
  • As an initial evaluation of the potential of digital elevation models (DEMs) and geographic information systems (GISs) for geomorphic characterization of rocky shorelines, airborne laser scan (ALS) data have been used to characterize shore platforms
  • around Shag Point, southeastern New Zealand. The main challenge involved the delineation of the shore platform area in terms of landward and seaward extents.
  • Development of shore platforms on Kaikoura Peninsula, South Island, New Zealand. II : the role of subaerial weathering
  • Algae ; Coastal environment ; Coastal erosion ; New Zealand ; Shore platform ; South Island ; Tide
  • The role of subaerial weathering in the development of shore platforms on Kaikoura Peninsula is investigated. Evidence for weathering came from a number of distinctive surface morphologies on platforms : salt crystal growth, water layer weathering
  • , and slaking. Weathering processes on shore platform rely on repeated wetting and drying. It was found that the number of wetting and drying cycles depend not only on the pattern of tidal water levels but also on algae growth and desiccation. It is argued
  • that the development of shore platforms at kaikoura results from subaerial weathering caused by repeated wetting and drying, and not from marine erosion.
  • Development of shore platforms on Kaikoura Peninsula, South Island, New Zealand. Part one : the role of waves
  • Coastal dynamics ; Coastal environment ; Coastal erosion ; Marine hydrology ; New Zealand ; Shore platform ; South Island ; Wave
  • The role of waves in shore platform development has been investigated on Kaikoura Peninsula by direct measurement of waves in deep water and on platforms at high tide. This showed that the deepwater wave environment off the Kaikoura Peninsula
  • is very energetic, but the amount of energy delivered to platforms is very low. An analysis of the role of breaking waves revealed that these are ineffective as an erosional agent because the depth of water offshore causes breaking before waves arrive
  • on platform surfaces.
  • Shore platform development around Lord Howe Island, southwest Pacific
  • Bathymetry ; Coastal environment ; Coastal erosion ; Conceptual model ; Holocene ; Island ; Lithology ; Pacific Region ; Sea level ; Shore platform ; South-West Pacific Ocean ; Submarine geomorphology
  • This paper describes the morphology of near-horizontal basalt and calcarenite shore platforms around Lord Howe Island as well as the lithological and process environment in which they occur. Correlations indicate that the variability in platform
  • elevation and width is attributable to variability in key parameters of erosion, such as rock resistance and shoreline water depth. Most platforms around the island appear to have developed over the Holocene and a conceptual model is proposed to account
  • for the varied morphology of platforms that have developed over this period.
  • Rates and patterns of erosion on inter-tidal shore platforms, Kaikoura Peninsula, South Island, New Zealand
  • Coastal environment ; Coastal erosion ; Erosion rate ; New Zealand ; Seasonal variation ; Shore platform ; South Island ; Terminology ; Weathering
  • This paper presents measured rates of erosion on shore platforms at Kaikoura Peninsula. Surface lowering rates were measured with a micro-erosion meter and traversing micro-erosion meter. Differences in lowering rates were found between different
  • platform types and lithologies. Season is shown statistically to influence erosion rates, with higher rates during summer than winter. The interpretation given to this is that the erosive process is subaerial weathering in the form of wetting and drying
  • and salt weathering. This is contrary to views of shore platform development that have favoured marine processes over subaerial weathering.
  • A well-developed raised shore platform (the Main Rock Platform) is described from Jura, Scarba and NE Islay, Scottish Inner Hebrides. Levelling of 175 platform fragments (approximately 1,000 altitude measurements) indicates that the feature declines
  • that the traditional correlation between the Main Rock Platform and a low Irish (interglacial) platform should be abandoned. Processes of shore platform development in polar areas are also discussed.
  • Zur Mobilität tektonischer Einheiten des westlichen Teils der Osteuropäischen Plattform. (Mobilité des unités tectoniques dans la partie ouest de la plate-forme d'Europe orientale)
  • On the basis of an analysis of the palaeodynamic development of zones of active subsiding of the western part of the East-European Platform (Baltic-Syneclise, Oslo-Schonen Depression, Danish Embayment) we are acquainted with the character
  • , the spatial and temporal processes and the changing behaviour of mobility of platform structures near the marginal zone. These investigations are based upon a model of the tectonic limitation and division of this part of East-European Platform. The mobility
  • of specific structures is represented in subsidence diagrams as well as in table on the palaeotectonic development of partial areas of East-European Platform.
  • Dune calcarenite and shore platforms at Cape Otway, Victoria
  • Cape Otway is a bold headland cut in Lower Cretaceous sandstones, bordered by cliffs and shore platforms. It is partly overlain by Pleistocene dune calcarenites and Holocene calcareous dunes resulting from eastward migration of aeolian sand from
  • beach sources on the western shore. Locally, this material has spilled over the eastern shore, where there are sectors of cliff and shore platform cut in Pleistocene dune calcarenite, interrupting the Lower Cretaceous outcrop. It is deduced
  • that the Pleistocene dunes spilled over an old cliffed coastline and on to a shore platform that had emerged as the result of sea level lowering. The present coastal features are thus very close to Pleistocene coastal features (cliffs, shore platforms) developed when
  • Rates of tafoni weathering on uplifted shore platforms in Nojima-Zaki, Boso Peninsula, Japan
  • Many tafoni occur on the faces of marine cliffs on three uplifted shore platforms with different altitudes and with known ages of emergence. The AA. estimate the mean value of the ten largest depths of tafoni, the period of their formation
  • Governance in Flanders'regional policy : subregional platforms as development coalitions
  • . The platforms contribute to a governance structure that enables public participation in policy-making.
  • Emphasis is on the paleogeography reflected by lithofacies in the carbonate platforms on both basins. The Belgian carbonate platforms appear to have a Pacific faunal/particle affinity| they evolved from rimmed margin to knoll-reef rimmed ramp
  • platforms. (LW).