Bedded dolomites in the Permian Basin were formed by the alteration of metastable limestones
by hypersaline brines refluxing from evaporate lagoons. The hot, heavy, highly alkaline, carbon dioxide-
free, magnesium-supercharged brines displaced connate waters to provide both a chemically favorable
environment for maenesium-calcium exchanee and a vehicle for removinr displaced calcium. Fossil laeoonal
onnes ana nnmgs of name ana annyartte in the aotomtte pores oner proof of the ortne invasion. aeaiment-
ary dolomites in other areas are commonly associated with evaporates, and for these dolomites a similar
origin is postulated.