A distribution‐free statistical method for the spatial characterization of dune granulometry: an example from the Strzelecki Desert, South Australia

Abstract

Distribution-free statistical methods of comparative data analysis have identified subtle granulometric differences attributed to the evolution of barchan form at Gurra-Gurra waterhole. Geomorphic locations on the barchan dunes display statistically significant grain-size differences that assist in the interpretation of aeolian processes. In summer, very fine sands mantle the dunescape and are the fraction that most affects the parameters of sorting and skewness. The surficial sedimentological character is one of subtle contrasts between the processes of grain winnowing and intergranular protection. The second and third moment measures are parameters that best demonstrate the spatial granulometric differences. Dune-forming processes at Gurra-Gurra have produced dune sands that have a very narrow range of grain size, which, in turn, reflects textural and mineralogical maturity, and hence an extensive transport history. The statistical techniques employed in this study can also be used for the comparison of temporal (seasonal) sedimentological change, and for the granulometric analysis and association of process for dunes of different morpho-types.

Dune field development, interactions and boundary conditions for crescentic and stellate megadunes of the Al Liwa Basin, the Empty Quarter

“…A comparable process has occurred in the preservation of linear dunes for parts of the Simpson‐Strzelecki desert in which indurated montmorillinite‐bound truncation surfaces are commonplace within the stratigraphic sequence of many dunes (Bishop, , ). In this instance, it appears that clay fines distributed by aeolian suspension were laterally concentrated in the growing dunes via near‐surface intergranular winnowing and precipitation events (Bishop, ). The development of such surfaces, whether they are surface crusts or cementation by bottom‐up infiltration from groundwater brines, are mechanisms that appreciably lower erodibility, hence mobility, availability and the recyclability of aeolian deposits.…”

“…Each data point (n = 34 RoIs) consists of dune numbers which range between, 151 ≤ star forms ≤ 588, and 185 ≤ crescentic forms ≤ 313. The crescentic dunes suggest an evolutionary pathway which is an organized aeolian sub-system of constructive processes, while the star dunes represent a near-chaotic sub-system of possibly regenerative mechanisms.This figure is available in colour online at wileyonlinelibrary.com/journal/espl distributed by aeolian suspension were laterally concentrated in the growing dunes via near-surface intergranular winnowing and precipitation events (Bishop, 2004). The development of such surfaces, whether they are surface crusts or cementation by bottom-up infiltration from groundwater brines, are mechanisms that appreciably lower erodibility, hence mobility, availability and the recyclability of aeolian deposits.…”

Mapping and characterization of small-scale aeolian structures on Mars: An example from the MSL landing site in Gale Crater

“…However, dune grain size segregation is a well known process (Bishop, 2004;Lancaster et al, 2002), which we are not able to spatially constrain in the equation.…”

The use of grain‐size distribution patterns to elucidate aeolian processes on a transverse dune of Thar Desert, India

“…Abuodha (2003) studied the impact of aeolian processes on the grain size distribution and observed that the pattern in grain size distribution is complicated by the presence of vegetation, heavy mineral concentrations, bioturbation, surface markings, ripples, swash bars and runnels. Many other investigators elucidated the aeolian processes on desert dune (Bishop, 2004;Kasper-Zubillaga and Carranza-Edwards, 2005;Kasper-Zubillaga et al, 2007).…”