inscription
Portail d'information géographique

Résultats de la recherche (857 résultats)

Affinez votre recherche

Par Collection Par Auteur Par Date Par Sujet Par Titre
Effects of lithology, time and exposure on the stabilization of loess mantled slopes. A comparative study in Loess (INQUA).
  • Effects of lithology, time and exposure on the stabilization of loess mantled slopes. A comparative study in Loess (INQUA).
  • The quantitative analysis presented in this paper seems to indicate that lithology, time and slope exposure do have effects on the process of slope stabilization in loess and other young, unconsolidated sediments.
Is typical loess older than one million years? in Lithology and stratigraphy of loess and paleosols.
  • Is typical loess older than one million years? in Lithology and stratigraphy of loess and paleosols.
  • Recent analyses of loesses indicate that the lithologically sensu stricto true loesses are not older than the Jaramillo event (0.9 m.y. B.P.). The features of the so-celled loess-like sediments or loess derivates are summarized. Paleomagnetic
Pleistocene stages in the Middle Dnieper basin by evidence of spore-pollen analysis of loesses in Lithology and stratigraphy of loess and paleosols.
  • Pleistocene stages in the Middle Dnieper basin by evidence of spore-pollen analysis of loesses in Lithology and stratigraphy of loess and paleosols.
  • Sudden alternations of warm and humid climatic stages with cool and arid ones are observed. The types of vegetation cover are indicated for stages and areas. (DLO).
Loess microtextures and the origin of loess in China in Lithology and stratigraphy of loess and paleosols.
  • Loess microtextures and the origin of loess in China in Lithology and stratigraphy of loess and paleosols.
  • On the basis of scanning electron microscopic analyses, the microtextures of loess indicate that the origin of loess in China is complex, but the main factor in genesis is the eolian. Pedogenesis must not be overlooked in the process of loess
Rock surface roughness as an indicator of degree of rock surface weathering
  • Rock surface roughness as an indicator of degree of rock surface weathering
  • Least squares method ; Lithology ; Methodology ; Mountain ; Norway ; Regression analysis ; Relative dating ; Roughness ; Weathering
  • . The efficacy of the proposed approach is demonstrated using case studies involving different lithologies and weathering environments.
Stream incision and terrace development in Frijoles Canyon, Bandelier National Monument, New Mexico, and the influence of lithology and climate
  • Stream incision and terrace development in Frijoles Canyon, Bandelier National Monument, New Mexico, and the influence of lithology and climate
  • Climatic variation ; Fluvial processes ; Fluvial terrace ; Geochronology ; Lithology ; Longitudinal section ; New Mexico ; Quaternary ; Stream ; Tufa ; United States of America
  • excellent constraints on the time frame and initial conditions associated with evolution of the canyon. Evidence from terraces in Frijoles Canyon indicates that development of the stream profile has been strongly influenced both by climatic changes
  • and by lithologic variations within the watershed, and the effects of tectonics have been subordinate.
Soil development indices of soils developed on fluvial terraces (Peñaranda de Bracamonte, Salamanca, Spain)
  • Soil development indices of soils developed on fluvial terraces (Peñaranda de Bracamonte, Salamanca, Spain)
  • Chronosequence ; Fluvial terrace ; Lithology ; Pedogenesis ; Quaternary ; Salamanca ; Soil ; Soil properties ; Spain
Lithological and stratigraphical analysis of loess profiles of the Loess Plateau in China in Lithology and stratigraphy of loess and paleosols.
  • Lithological and stratigraphical analysis of loess profiles of the Loess Plateau in China in Lithology and stratigraphy of loess and paleosols.
  • A detailed stratigraphic division of loess deposits in three selected profiles was carried out based on lithologic and paleomagnetic analyses. (DLO).
Timescales and the role of inheritance in long-term landscape evolution, northern New England, Australia
  • Australia ; Drainage network ; Earth surface processes ; Fluvial processes ; Lithology ; New South Wales ; Paleogeography ; River bed ; Tectonics ; Volcanism
  • The general coincidence between lithology and landform indicates that little tectonic deformation has occurred in the study area since the Permian. This suggests that the earstern highlands in the area may have been formed by the denudation
Conditions for generation of fire-related debris flows, Capulin Canyon, New Mexico
  • Fire ; Flood ; Impact ; Lithology ; Mudflow ; New Mexico ; Rainstorm ; Soil erosion ; United States of America ; Watershed
  • Comparison of the responses of 3 drainage basins burned by the Dome fire of 1996 in New Mexico is used to identify the hillslope, channel and fire characteristics that indicate a susceptibility specifically to wildfire-related debris flow. Summer
  • thunderstorms generated 3 distinct erosive responses from each of 3 basins. The factors that best distinguish between debris-flow producing and flood-producing drainages are drainage basin morphology and lithology.
Absence of last glacial maximum records in lowlan tropical forests
  • Amazon Basin ; Brazil ; C 14 dating ; Lateglacial ; Lithology ; Mineralogy ; Palaeo-environment ; Palaeoclimate ; Palynology ; Quaternary ; Sedimentology ; Tropical rain forest
  • Environmental conditions of the lowland tropical forests during the last glacial maximum (LGM) between ca 20,000 and 18,000 C 14 yr B.P., are reevaluated in terms of dating control and lithology analyzed in seven pollen records from South America
  • . The results suggest that the LGM was represented probably by a hiatus of several thousand years, indicative of drier climates than before or after.
Stratigraphy and lithology of Late Pleistocene sediments at Mosvatn Hardangervidda, South Norway
  • Stratigraphy and lithology of Late Pleistocene sediments at Mosvatn Hardangervidda, South Norway
  • Stratigraphic, textural, minerological, geochemical and palynological investigations indicate the existence of: lacustrine clay from the Late Eemian (Hovden thermomer)| dark clayey basal till of the Early Weichselian age (Hovden kryomer)| lacustrine
Dunantuli és Duna-Tisza kozi loszfeltarasok uj szempontu litologiai értékelése és tipizalasa. (A new lithological evaluation and typification of loess exposures in Transdanubia and on the Danube-Tisza Interfluve)
  • Dunantuli és Duna-Tisza kozi loszfeltarasok uj szempontu litologiai értékelése és tipizalasa. (A new lithological evaluation and typification of loess exposures in Transdanubia and on the Danube-Tisza Interfluve)
  • of tables, new names are suggested for loesses in the key sections supported by values of indicators of loess composition. (DLO).
Paleogeography of loess accumulation in the light of palynological data in Lithology and stratigraphy of loess and paleosols.
  • Paleogeography of loess accumulation in the light of palynological data in Lithology and stratigraphy of loess and paleosols.
  • Palynological evidence indicates more diverse climatic conditions for loess accumulation in the various regions of the USSR than it had been supposed earlier. Loess-like deposits formed in desert, semidesert, steppe, forest-steppe or tundra-steppe
Facial changes in the material composition of Upper Pleistocene loesses in western and eastern regions of the European USSR: a case study of Volyno-Podolia and the Dnieper basin in Lithology and stratigraphy of loess and paleosols.
  • Facial changes in the material composition of Upper Pleistocene loesses in western and eastern regions of the European USSR: a case study of Volyno-Podolia and the Dnieper basin in Lithology and stratigraphy of loess and paleosols.
  • In the west, minerals are more weathered. The data correspond with results of palynological, faunistic, cryological and other analyses and indicate a more humid climate for Volyno-Podolia in that time. (DLO).
Controls over landslide distribution in the White Mountains, New Hampshire
  • Geological structure ; Landslide ; Lithology ; Mass movement ; Mountain ; New England ; Slope ; Slope dynamics ; Statistics ; Topography ; United States of America
  • , examines the relative importance of lithology and geologic structure on slide occurrence, as well as the relationship between topography and slide morphology. Results indicate that the frequency of slide scars is significantly higher in sections underlain
  • by metasedimentary lithologies than in areas dominated by plutonic rocks.
The effect of land use change on soils and vegetation over various lithological formations on Lesvos (Greece)
  • The effect of land use change on soils and vegetation over various lithological formations on Lesvos (Greece)
  • Arid area ; Desertification ; Greece ; Island ; Land use ; Lithology ; Mediterranean area ; Soil erosion ; Soil properties ; Vegetation ; Wasteland
  • The effect of land use change, from arable to abandoned pasture, on soil properties and vegetation establishment was studied in hilly areas of the island of Lesvos. The main purpose of this study was to establish key indicators or land parameters
Hydrogeomorphic effects of basin lithology on development of channel steps in first-order basins of the Ashio Mountains, Japan
  • Hydrogeomorphic effects of basin lithology on development of channel steps in first-order basins of the Ashio Mountains, Japan
  • Channel geometry ; Experimental catchment ; Honshu ; Japan ; Lithology ; Longitudinal section ; Mountain ; Sediment load ; Sediment transport ; Stream ; Watershed
  • processes affect channel-step morphology, indicating that lithology plays a key role in the formation of channel steps and in variations between headwater streams.
  • This study focuses on lithological contrasts of headmost channel morphology of 2 mountainous areas underlain by chert or sandstone. The areas have contrasting runoff processes : subsurface storm flow predominates in the chert area, whereas
Glacier dynamics around Slieve Bloom, Central Ireland
  • Esker ; Fluvioglacial features ; Glaciation ; Glacier fluctuation ; Ireland ; Lithology ; Moraine ; Piedmont ; Pleistocene ; Quaternary
  • Analyses of both till and glacioaqueous sedimentary fabrics and their lithological characteristics have been carried out on sediments sampled at 8 sites located around the northern margin and piedmont of Slieve Bloom, as indicators of both
  • the direction of ice flow towards and across Slieve Bloom and the transport distances of tills deposited in and around the mountains. These 2 sets of information give indications of both the provenance of glacigenic sediments and their route into Slieve Bloom
Geomorphology of the Cape Peninsula in Southern African landscapes : a geomorphological field guide.
  • The Cape Peninsula which includes Table Mountain is separated by the sandy Cape flats from the S.W. Cape Mainland. It is made up of various lithologies and includes various sites indicating higher sea levels in the past.