The major deposits of rock salt in Israel occur in the Dead Sea area of the Rift Valley. Here, a practically continuous sequence of salt was found by drillings to a depth exceeding 2700 m in the western, and to almost 4000 m in the eastern part, beneath a thin cover of late Pleistocene sediments. A shallow drill in the center of the southern Dead Sea basin itself penetrated salt to its maximum depth of almost 100 m. The extensive occurrence of salt in this area partly explains the high negative gravity anomaly in this part of the African Rift. At Mount Sdom, on the southwest corner of the Dead Sea, part of the salt mass is exposed on the surface. Mount Sdom, 10 km long and 1–2 km wide, rising 220 m above the present level of the Dead Sea, consists essentially of salt interbedded with sand, shales, anhydrite, and carbonate rocks. It is an uplifted fault block. Its internal structure is that of a compressed and partly overturned anticline truncated on its flanks. Intrusive salt features are essentially absent. A study of the Cl:Br ratio in the salts and associated brines leads to the conclusion that the salt is partly (Mount Sdom) of marine (?) and partly (Lisan Peninsula, southern Dead Sea) of continental origin. The Rift Valley, formed in mid-Tertiary time, was invaded in the Pliocene by the sea. In the following regressive phase, the salt of Mount Sdom was deposited. During most of the Pleistocene, a salt sequence, at least 4000 m thick, was laid down in the area under continental conditions; tectonic subsidence during the Pleistocene is of the same order of magnitude. Concurrently the block of Mount Sdom was uplifted; the last rise of about 100 m took place during the past 10,000 years.