A Comment on the article in this month's Geology about desication structures in the White Sands of New Mexico being cited as analogs to Martian sulfates. Does this article really refer to the razorbacks seen in Endurance Crater? These comprise a harder material than the rock matrix and thus are unlikely to be sulphates. In fact the VNIR spectra show then to be ferric iron-rich. Also they form along major fractures in the rock and are thus probably post-cratering. Hence they may represent a reactivation of fluid movement following cratering within a pile of fractures (and warmed) rock - hardly a gypsum dessication process.