In 1960–1980, the Elton and the Gremyachka deposits of potassium salts were discovered within the Permian halogen sequences in the Lower Volga Region, bischofite presence was recorded in the Privolzhskaya monocline, the conditions of halogen-bed formation were defined as those peculiar for typical evaporites. But in 1980-2010, halogenesis hypotheses emerged that denied the principal importance of climatic factor and the dominant role of oceanic waters in the brine composition of the salt-generating basin. Investigation of the basin brine composition (from the inclusion compositions) made by the authors has shown regular ratio of the brine principal components over the entire area of the salt-generating basin and at all the stages of halogenesis. This data univocally confirms the view that no impact of endogenous factor is manifested at the sedimentation stage of halogenesis. This conclusion does not extend to the posthalogenic history of the depression