In 1948-1951 traverses of unexplored country near the Persian Gulf between Bushire and Lingeh during exploration work by the British Petroleum Company Limited permitted investigation of nine emergent salt plugs additional to those previously described. Two possible non-emergent plugs were also located. The geology of different types of the emergent plugs is described with emphasis on features of regional and genetic significance. A recent suggestion that igneous activity has played an important part in initiation of Persian salt-plug movement is not supported by the detailed studies. The stratigraphy of the associated rocks shows a clear distinction between those which reached surface by middle Miocene or earlier and those associated with the Pliocene Zagros orogeny.

Many of the plugs located down-pitch on folds are of early origin, while those located on structural culminations are more commonly intra- or post-orogenic. This suggests that an early plug may have provided a point of weakness to initiate a later fold-line, but that exhaustion of the mobile Cambrian salt locally limited movement by Abscherung so that maximum fold development took place farther along the strike. The core of squeezed-up salt in the culmination might in turn become diapiric, but would be post-orogenic.