Desert pavement dynamics: numerical modeling and field‐based calibration

Abstract

Desert pavements are widely used as a relative surface-dating tool because they are progressively better developed on surfaces ranging from thousands to hundreds of thousands of years in age. Recent work, however, has highlighted the dynamic nature of pavements and undermined their use as surface-age indicators. Quade ( To calibrate the model, we conducted surficial geologic mapping and pavementsedimentological analysis on two desert piedmonts. Our study areas include both proximal and distal fan environments, illustrating the role of parent-material texture in controlling the mode of pavement formation. Using available geochronology, our work provides a rigorous calibration of pavement formation rates in our study areas and provides evidence supporting the use of pavements as local relative surface-age indicators over Holocene to late Pleistocene timescales.

Degradation of glacial deposits quantified with cosmogenic nuclides, Quartermain Mountains, Antarctica

“…A desert pavement caps the moraine surface today, and although desert pavements do sometimes form by the infl ation of eolian sands below a gravel armor (e.g. McFadden et al, 1987;Wells et al, 1995;Pelletier et al, 2007), there is no evidence of infl ation at this site. Rather, the pavement caps the poorly sorted till abruptly, indicating that the pavement formed as a lag and that this site has experienced some erosion since it was deposited.…”

Total vertical sediment flux and PM10 emissions from disturbed Chihuahuan Desert surfaces

“…In the absence of vegetation, desert pavements form as clasts are lifted to the surface by clays undergoing changes in hydration. This roughened surface encourages further deposition of wind-borne fine sediments (Pelletier et al, 2007;Matmon et al, 2009;Dietze et al, 2016) resulting in older surfaces with more clay and silt from aeolian accretion (Meadows et al, 2006). Periodic surface disturbances can heal in a matter of years if the clasts remain (Wainright et al, 1999) or decades if the clasts are completely removed (Haff and Werner, 1996;Pelletier et al, 2007).…”

“…This roughened surface encourages further deposition of wind-borne fine sediments (Pelletier et al, 2007;Matmon et al, 2009;Dietze et al, 2016) resulting in older surfaces with more clay and silt from aeolian accretion (Meadows et al, 2006). Periodic surface disturbances can heal in a matter of years if the clasts remain (Wainright et al, 1999) or decades if the clasts are completely removed (Haff and Werner, 1996;Pelletier et al, 2007). In spite of their historical stability, desert surfaces are mechanically fragile and may offer early warning of degradation from increased anthropogenic and macrofaunal activity (Haff, 2001).…”

Pavements and Stone Mantles

“…In Oman, a similar progression was noted on fans and wadi terraces of different ages (Al-Farraj and Harvey, 2000). With time, the topography is modified and smoothed, with a systematic decrease in bar-and-swale microtopography and a rounding of gully and terrace edges on older surfaces (Pelletier, Cline and DeLong, 2007).…”

“…Clearly, the development of the pavement and its underlying soil are influenced by dust and salt deposition rates, which not only vary with time but also are higher near source areas, such as playas. Thus, it is likely that rates of pavement development vary spatially (Pelletier, Cline and DeLong, 2007). In addition, Wood, caution that pavements often demonstrate a mosaic of disjunct fabrics and textures within short distances, although they may appear monotonous, flat and uniform at first glance.…”