Halogenesis

the process of formation by evaporation of brines in surface basins in an arid zone, leading to the formation of deposits of readily soluble salts.

There are two stages in halogenesis: a prolonged preparative one, when the main stocks of concentrated brines accumulate, and a short one, in which precipitates of readily soluble salts are formed from them. There are three main types of halogenesis—carbonate, sulfate, and chloride— differing in the collection of minerals and of the characteristic microelements. Depending on the genesis of the feed waters, halogenesis is subdivided into continental and marine; the latter has played a particularly large part in the earth’s history over a vast area. The requisite conditions for halogenesis to develop are an arid climate, the possibility of intensive feeding of a basin (for instance, with sea water) but without reverse flow of the concentrated brines, and constant and nonuniform sagging of the territory where salt deposition is taking place. The halogenic process gives rise not only to deposition of salts but also to basic stocks of highly concentrated brines in the depths of the earth.