Halite precipitates out after even more evaporation. Carbonate does not precipitation because of evaporation, but is primarily inorganic. Calcite is the most abundant carbonate in freshwater environments. Diatoms contribute most of the silica. The largest lacustrine sequence in the world.
Basins are in Wyoming, Colorado and Utah.
These are well developed horizontal rhythmites. Fossils include ostracods, gastropods, pelecypods, fish and algae. They coarsen upward and sometimes end with sandy convoluted beds. The base of the cycle is often a layer of pyrite overlaid by a mudcracked and bioturbated mudstone. The cycle documents increasing depth and increasing energy.