Optical and radiocarbon dating indicates that alluvium underlying dunes near Abilene was deposited at or before 45 ka, and that the overlying dunes were active at 1.1–0.5 ka. Geochemical data indicate that the Abilene dune sand is immature and was derived from the underlying Pleistocene alluvium, and not from Holocene age Smoky Hill River deposits. These findings suggest that dune activation wa...

Horqin Sandy Land is located in northeast China (4241’-4515’N, 11835’-12330’E). The wind-sand topography in Horqin Sandy Land can be described as two series--sand deposition and wind erosion. Wind is the natural force for the formation of wind-sandy environment, under windsandy environment, the wind erosion processes such as sand drifting, dust-storm, etc. occurred frequently because of the fre...

Sand dunes have been observed throughout the surface of the planet Mars. Movement of these dunes has been theorized and inferred from the lack of craters on dunes. Dune movement has not yet been directly imaged, however. Understanding sand movement processes is vital to a correct Martian climate model, as well as the safety of future missions to Mars. Imagery from several Martian orbiters was a...

this study aims to identify favorable oil–gas reservoir facies in the chishan group of the wubao fault zone (gaoyou sag, subei basin, china) using the methods of outcrops and cores observation, granularity analysis, scanning electron microscope, log data, etc. the results suggest that the chishan group in the studied area mainly develops desert sedimentary system, and contains five kinds of fac...

S U M M A R Y The current research presents ground penetrating radar images up to 30m in depth of two large desert dunes in California, USA— a barchanoid ridge in the Dumont field and a linear dune in the Eureka expanse. The radar images show a complicated structure of internal layering with ascending cross-strata, cross-bedding and bounding surfaces cutting through layers. Additional research ...

We propose a minimal model for aeolian sand dunes. It combines an analytical description of the turbulent wind velocity field above the dune with a continuum saltation model that allows for saturation transients in the sand flux. The model provides a qualitative understanding of important features of real dunes, such as their longitudinal shape and aspect ratio, the formation of a slip face, th...

Aeolian desert sand dunes birth from wind flow and sand bed interactions: depending on wind properties and sand availability, they can adopt several different shapes from huge motionless star dunes to small and fast mobile barchan dunes. These latter have a characteristic crescentic shape and form on hard ground with low sand supply under a monodirectional wind . Here, a 3d barchan model based ...

large areas of iran are under the influence of wind erosion thus it is important that we recognize three zones ofremoval, transportation and deposition. the deposition zone is very important due to more damages and tangibleeffects. in this study we try to obtain a comprehensive idea to persian desert with use of laboratory facilities, remotesensing, gis and field surveying. we survey 28 ergs in...

Whether the winds of the present Mars are shaping the variety of dune forms observed on the Martian surface has remained an open question that challenged planetary scientists for decades. In order to elucidate this issue, we have studied sand transport and dune formation from two different points of view. The first approach consists of solving the equations of aeolian transport at the level of ...