Sand columns, sand cones, sand mushrooms and other striking sand forms are frequently observed in the Dutch and German beach and dune sands. The objective of this study is to describe, explain and illustrate the origin of sand columns in bare dune
Sand transport and deposition within arrays of non-erodible cylindrical elements
This study concerns sand deposition within a regular array of vertical cylinders placed in the path of a sand-laden wind. 12 wind tunnel experiments using 3 preselected shear velocities, with associated rates of sand feed, and 4 roughness element
concentrations were carried out to evaluate the factors that affect sand deposition and sand flux in the presence of immobile rough elements. The sand deposition and sand flux along an array consisting of regularly distributed, non erodible elements were shown
Field studies of sand patch initiation processes on the northern margin of the Namib Sand Sea
Aeolian features ; Aeolian transport ; Arid area ; Desert ; Dune ; Geomorphometry ; Namibia ; Roughness ; Sand ; Wind speed
Some parts of the interdune areas on the northern margin of the Namib Sand Sea are characterized by areas of thin sand sheets and sand patches 1 to 10 m across and a few centimetres thick that appear to be protodunes. This paper documents
their morphology, distribution and short-term dynamics and examines sand patch distribution in relation to changes in surface roughness and boundary-layer winds.
Sand transport takes place when the wind speed is higher than some critical value. When the wind speed is not too high and the sand has a monodisperse size distribution it is possible that ripples are formed. Simple relationships are derived between
the wavelength of the ripples, the sand-grain motion, and the increase in drag due to sand transport. The theoretical results are in agreement with field observations.
In this paper a more differentiated subdivision of the sand deposits is suggested. Only the lower part of the different profiles should be determined as the fluvial « Hönninger Sande » in a specific sense. The thick upper parts of the sand deposits
however consist of reworked sediments, among others the « Hönninger Sande ». They are then called « Linzer Sande ».―(L'A.).
Composition and sources of sand in the Wahiba Sand Sea, Sultanate of Oman
Arid area ; Discriminant analysis ; Dune ; Erg ; Geochemistry ; Grain size distribution ; Mineralogy ; Oman ; Sand
The Wahiba Sand Sea is composed of 2 physiographic units that can be roughly divided into northern and southern regions. The Northern Wahiba is predominantly a large megaridge system, whereas the Southern Wahiba mostly comprises linear dunes, sand
sheets, and nabkha fields. Although the dunes of the 2 regions are of different ages, it has previously been hypothesized that their sans were derived primarily from the same source, namely coastal sands.
This thesis presents the results of an investigation of the geomorphology, the origin and the age of the drift sands in Drenthe, a province in the northern part of The Netherlands. - (AGD)
A study of sand color and maturity in Saudi Arabia
A Color Maturity Index based on measurements using a colorimeter is proposed. The color of the sand appears to be mainly related to the nature of the source material. Evidence indicates that eolian sand in most dune fields have only moved locally.
Sublimation and aeolian sand movement from a frozen surface: experimental results from Presqu'ile Beach, Ontario
Aeolian features ; Canada ; Cold area ; Frozen ground ; Ontario ; Sand ; Soil moisture ; Temperature ; Wind speed
The Presqu'ile field study was designed to provide quantitative information on sublimation from frozen sand surfaces under field conditions. This goal was pursued through the following objectives: 1) to assess (by experimental means) the rate
of sand loss from a frozen surface as a result of sublimation. 2) to find a relationship between sublimation-initiated sand loss and sand moisture content, temperature, relative humidity, and wind speed.
The Vlierzele sands (Eocene, Belgium) : a tidal ridge system in Tide-influenced sedimentary environments and facies.
It is suggested that the Vlierzele Sands (late Lower Eocene) represent a longitudinal tidal sand ridge deposit. They consist of regular, cm- to dm-scale, cross-bedded sands originating from mobile, 20 cm-50 cm high, two-dimensional megaripples
. In the lower ranges of this facies, the intact megaripple forms have been preserved under a cover of vaguely horizontally laminated sands. The latter could be the result of rapid storm deposition on the lower flank of the sand ridge. - (Les AA.).
Cold events of Holocene indicated by primary elements distribution of the high-resolution sand dunes in the Salawusu River Valley
C 14 dating ; China ; Dune ; Geochemistry ; Geochronology ; Holocene ; Inner Mongolia ; Palaeo-environment ; Sand ; Stratigraphy
This paper summarizes the dune sands layer of MGS1 stage in Milanggouwan section first, then compares it with the related chemical elements and detrital minerals of modern dune sands, and identifies the time of each layer of dune sands by the age
examining results and sediment ratio, discussing the causes of dune sands and the cold events indicated by them.
Bypassing of sand over sand waves and through a sand wave field in the central region of the Southern North Sea in Tide-influenced sedimentary environments and facies.
A sand wave field lies uncomfortably in the middle of a slightly undulating, current swept lag gravel pavement between Sandettie and South Falls banks in the central region of the Southern Bight of the Southern North Sea. - (L'A.).
Relationship of the geomorphological position, genetic, physical, chemical and mineralogical features of sand soils with their fertility in Lithology and stratigraphy of loess and paleosols.
The sand soils of the cooperative farm under investigation can be classified as follows: 1. Soils of high fertility, a. multi-layer humous sand soils, b. sandy chernozem meadow soils| 2. Soils of medium fertility, humous sands| 3. Soils of low
fertility, a. blown sand soils, b. sand mantle soils. (DLO).
To understand, and perhaps predict, something of the movement of these barchan sand dunes, the A. undertook a study of the dunes using aerial photographs. This led to a general study of sand movement in the surrounding region.
Nature, chronostratigraphy and origin of late Holocene coastal sands at Portrush, Co. Antrim
Aeolian features ; Chronostratigraphy ; Coastal environment ; Grain size distribution ; Holocene ; Northern Ireland ; Palaeogeography ; Pedogenesis ; Plant colonization ; Sand ; United Kingdom
Detailed analyses of a small exposure in coastal sands at Portrush, Co. Antrim, have yielded data that enable inferences concerning the origin and depositional history of the sands to be made. Site location, elevation, grain-size characteristics
, and C 14 dating, along with data from a nearby site, combine to suggest that the basal sands at Portrush may result from marine processes during extreme events. The overlying sands are probably aeolian, reworked from the underlying marine sand
, and contain buried organic-rich horizons that indicate sand depositional phases alternated with stability phases during which vegetation colonisation and pedogenesis occurred.
Mineralogical characterization and transport pathways of dune sand using Landsat TM data, Wahiba Sand Sea, Sultanate of Oman
Aeolian features ; Aeolian transport ; Arid area ; Carbonate ; Cluster analysis ; Dune ; LANDSAT ; Mineralogy ; Monsoon ; Oman ; Remote sensing ; Sand ; Thematic Mapper
Sand samples and Landsat imagery were used to characterize the spatial distribution of sand mineralogy, and to evaluate potential sources and transport pathways of sediment in the Wahiba Sand Sea in the Sultanate of Oman. Landsat TM data were useful
in the geomorphic interpretation of a desert, aeolian environment to distinguish the mineralogies found in the Wahiba area, and in extending the identification of sand mineralogy beyond the point-specific grid produced from field sampling.
Horizontal water trap for measurement of aeolian sand transport
A new type of horizontal trap was developed for measuring the aeolian sand transport rate on a flat surface. The trap consists of an adjustable frame that is embedded level with the sand surface, into which a plastic liner is installed and filled
with water to capture the blown sand. The water trap has high efficiency and does not disturb the wind field or induce upwind scour. Deployment on Padre Island, Texas, indicated that this portable and adjustable trap catches and retains all the sand blown
Thermoluminescence dates and palaeoenvironmental information of the late Quaternary sand deposits, Tierra de Pinares, Central Spain
Aeolian features ; Arid area ; Castilla-León ; Dating ; Palaeo-environment ; Quaternary ; Sand ; Spain ; Thermoluminescence ; Wind
The focus of this paper, is a widely distributed sand which covers most of the Tierra de Pinares, north of Segovia. The AA. report the results of an investigation into the extensive sand deposits around Burgomillodo. They interpret the timing
and palaeowind direction of the aeolian phases of sand deposition.
Micromorphological analysis of five sections, partly with a macroscopically traced gradual transition, partly with an abrupt boundary, shows that in all cases no hiatus occurred between the peat and the drift sand. Consequently the radiocarbon dates
of the upper part of the peat do not give a date postquem for the drift sands, but represent dates during the early phases of sand drifting.