“…However, the occurrence or continuation of fine-grained thenardite along the sides and base of various structures, including thin horizontal thenardite-bloedite plates, lateral extensions from surface protrusions, and the sample as a whole, indicates formation along the surface of preexisting deposits, rather than growth and sedimentation within the water column. The most likely process is replacement of bloedite by thenardite, which has only rarely been reported (Ordóñez et al, 1994), in contrast to the reverse reaction (Mees, 1999;Li et al, 2010;Mees & Tursina, 2010). The cause of the common separation between the layer and the crust is not apparent.…”