A level of salinity intermediate between normal marine and hypersaline, ranging from 72‰ to 352‰. These salinity levels are high enough to be toxic to normal marine organisms, and can be tolerated by only a restricted range of fauna and flora. The characteristic sediments of penesaline zones are evaporitic carbonates (see evaporite) interbedded with anhydrite or gypsum. Penesaline environments are often encountered in the back-barrier and backreef zones.