Linear Gullies (Mars)

Description/Morphometry

This feature appears only on sandy slopes (especially dune slopes). It consists primarily of a long (few hundred meters up to 2.5 km) groove of near-uniform width (generally a few to ten meters wide and sometimes with slight narrowing downslope) and is near linear (but may contain zones of low-to-high sinuosity) (Fig. 1). Groove depth is usually from <1 m to 2 m. It is commonly surrounded by lateral deposits interpreted as levees. The groove is generally topped by a small alcove and/or converging small grooves (Fig 2). Downslope, the groove abruptly ends: sometimes ending with a terminal pit or sometimes a series of divergent small grooves, each with a terminal pit, or chain of pits with diameter often larger than the groove width, but lacking a debris apron (Figs. 2d and 3). Grooves sometimes converge downslope (Fig. 2). Except within the very distal portion, they do not diverge (Costard et al. 2002; Diniega et al. 2013; Mangold et al. 2003; Miyamoto et al. 2004)....