Various workers have suggested that the Upper Miocene (Messinian) evaporites of the Sicilian Basin formed in a topographic basin of considerable relief, filled with hypersaline water. Our studies indicate that this basin contained shallow water, at least during the deposition of the carbonate rocks intercalated between the gypsum beds. We recognize four basic kinds of limestone: (1) pelletal and pisolitic limestone; (2) skeletal limestone; (3) oöitic limestone, and (4) laminated lime-stone-dolostone. Modern analogs suggest that three of these four kinds of carbonate must have formed close to or above sea level. The evidence supporting this contention includes pellets with algal coatings, pisolites, quiet-water oöids, and algal laminates. Therefore we suggest that the evaporites associated with these carbonates may likewise have formed in relatively shallow water. An alternative conclusion would be that the level of the sea, and the salinity, underwent irregular patterns of profound change.