This paper presents a study of the salt domes of the Gulf states, on the basis of printed information and personal communications from geologists of the American Association of Petroleum Geologists, as interpreted by the writer. The concentration of salt is attributed to evaporation of inland seas, chiefly during Permian time, when an arid climate prevailed in the interior of North America. The causes of aridity are discussed. Actual occurrences of salt brines are described.

In the theoretical discussion the origin and the mechanics of domes are considered as explained by the prevailing hypothesis of sedimentary origin, the Sedimentary hypothesis, and by an Artesian hypothesis. The latter substitutes artesian flow for load mechanics as the cause of development of domes and appeals to atomic forces for the growth of the structures. Any salt dome is hypothetically regarded as an intrusive mass, which receives additions to its volume, molecule by molecule, from brines that rise from warmer to cooler horizons and reach the saturation point. The force of growing crystals is regarded as the cause of upthrust of the dome and of the crushing of the salt itself. The presence of anhydrite is explained as due to crystallization in the order of insolubility, whereas he absence of potash salts is caused by their greater solubility. The article in general invites discussion of some old ideas and offers some additional suggestions.