The status of ravine-like incisions in the dryvalleys of the Pays de Thelle (Paris basin, France)
France ; Geomorphometry ; Gully erosion ; Human impact ; Ile-de-France ; Neotectonics ; Oise ; Palaeo-environment ; Sedimentology ; Valley
This study attempts to explain the development of the incisions in the dryvalleys of the Pays de Thelle. The objectives are to locate and measure the dryvalleys and the gullies, to analyse the factors favourable to their formation
Note on the origins of the dry zone of the Limpopo Valley
Cloud bands over the western Indian Ocean are bimodally distributed in space. On mode crosses South africa and the second mode Malagasy. The Limpopo valley lies between the modes and it is proposed that this fact explains the relatively low rainfall
Griffith Taylor's palimpsest theory of the DryValleys of Victoria Land, Antarctica
Griffith Taylor was the first geomorphologist to work in the DryValleys of southern Victoria Land, Antarctica. He proposed a multistage model in which earlier cirque erosion was later swamped by expanding outlet glaciers. Subsequently
these glaciers retreated leaving the present form of the valleys. The topography retained the imprint of each episode, hence his name palimpsest theory. The A. summarises later research and compares Taylor's theory with current views.
Origin and palaeo-environments of calcareous sediments in the Moshaweng dryvalley, southeast Botswana
Quaternary sedimentation in the Moshaweng dryvalley of southeastern Botswana is evaluated on the basis of geomorphological evolution and sedimentological analyses. Stratigraphic evidence reveals an upper surface containing abundant sil-calcrete
palaeoenvironmental information and provide tentative dating relating to valley formation.
Use of soil chronosequences for testing the existence of high-water-level lakes in the McMurdo DryValleys, Antarctica
The AA. utilize field observations and data collected from 190 pedons from Wright and Taylor Valleys to search for evidence of high-water-level lakes proposed to have existed during the last Glacial Maximum and early Holocene in the McMurdo Dry
Valleys. The results cast doubt as to whether high-level lakes existed in the McMurdo DryValley as recently as the early Holocene. An alternative explanation is that the former lakes had no effects on soils other than depositing deltas with cyanobacteria
East Antarctic Ice Sheet sensitivity to Pliocene climatic change from a dryvalleys perspective
paleoclimate and ice sheet history. Then they test these predictions from an examination of landscape development and surficial sediments in the DryValleys sector of the Transantarctic Mountains.
Permafrost distribution and active-layer depths in the McMurdo DryValleys, Antarctica
The aim of this study is to : 1) establish a permafrost database for continental Antarctica and 2) construct permafrost distribution and active-layer depth maps of key ice-free areas and the McMurdo DryValleys as a whole. Using a combined dataset
Linear dune pattern variability in the vicinity of dryvalleys in the southwest Kalahari
Aeolian features ; Aerial photography ; Arid area ; Barchan ; Botswana ; Dune ; Geomorphometry ; Kalahari ; Palaeo-environment ; Valley ; Wind
This paper describes the main association between dunes and valleys which occur in the southwest Kalahari dunefield and to review current explanations from localised dune pattern evolution and development in this and other dunefields of low relative
relief. The study is based upon a combination of field observations, analysis of aerial photographs and map interpretation of the dunes within 10 km of the major valleys which dissect the southwest Kalahari dunefield.
Interactions between airflow and valley topography with implications for aeolian sediment transport
Aeolian features ; Aeolian transport ; Arid area ; Desert ; Model ; Namibia ; Topography ; Valley ; Wind ; Wind speed
upwind, within and downwind of a dryvalley in the central Namib desert. A conceptual model indicating the potential implications of these data for aeolian sediment transport processes in the vicinity of dryland valleys is presented.
This paper investigates the impacts of dryland valley topography on wind speed and direction in order to understand better the effects of a valley on aeolian sediment dynamics. Anemometers and wind vanes were used to measure airflow characteristics
Vyvoj udoli a kvartérni tektonika Hlucinské pahorkatiny. (Valley development and Quaternary tectonics in the Hlucinska pahorkatina) (hilly land)
Dells, dryvalleys, river valleys, cryopediments as well as valley asymmetry are described in the model area of Pleistocene deposits. Special attention is devoted to the role of Quaternary tectonics in valley development. The hilly land of Hlucin
The A. deals with the vegetation of the Himalayas taking his 1957 map as basis of the presentation. This map reveals the phenomenon of the inner valleys and the climatically dryvalleys. Progress in the knowledge of the vegetation since publication
Asymmetrical valleys of periglacial origin in south-eastern Hesbaye, Belgium
In south-eastern Hesbaye, where very few courses of running water exist, shallow linear depressions observed on the plateau form a fossil drainage pattern. These dryvalleys are cut in the loess cover. Their cross-profile is asymmetrical, due
Thermal characterisation of active layer across a soil moisture gradient in the McMurdo DryValleys, Antarctica
Antarctique ; Bilan énergétique ; Changement climatique ; DryValleys ; Humidité du sol ; Modèle numérique ; Mollisol ; Périglaciaire ; Température du sol
soils (compared to the rest of the McMurdo DryValleys landscape), and to assess the response of the active layer to possible increases in soil moisture. The AA. measured subsurfaces temperatures at depths from 3 to 50 cm at 4 locations along a natural
Here, the AA. present results of a study to characterise soil thermal properties along a soil moisture gradient adjacent to Lake Fryxell in Taylor Valley, Antarctica. The goals were to characterise the thermal characteristics of these relatively wet
gradient of wet to dry soils adjacent to Lake Fryxell from January 2006 to January 2007. They used a numerical model to estimate apparent thermal diffusivity (ATD) and simulate observed temperature time series. Estimated bulk ATD values were consistently
Landform and sediment associations of dry-based glaciers in arid polar environments
The objective of this study was to determine whether the dry-based glaciers of the DryValleys of southern Victoria Land, Antarctica, form a land system and sediment association that is different from the other thermal types. This paper examines
and interprets the ice marginal sediments and landforms of several glaciers in the Taylor and Wright valleys. The principal characteristics of the ice marginal landforms and sediments are compared and contrasted with the existing facies model for arid polar
Valley formation initiated by ice wedge polygonal nets in terrace surfaces
Based on observations of present day valley formation through thermokarst processes in river terraces of Spitsbergen, some mainly fossil valleys (gullies) in marine terraces of the Varanger peninsula are analysed. A more developed, dryvalley