SALT TECTONICS IN THE PUNJAB SALT RANGE, PAKISTAN1

Salt deposits occur in two areas in western Pakistan: one near Kohat west of the Indus River, and the other in the Punjab Salt Range between the Indus and Jhelum rivers (lat. 35° N.; long. 71°–74° E.). The Salt Range is the south-facing scarp of the Potwar Plateau. The plateau is formed by a great thickness of sedimentary rocks which have been thrust southeastward between two wedges of the Indian Peninsula toward Kashmir and Waziristan. The strata in the Potwar basin (whose southern border is the Salt Range) are gently folded in the south but progressively more intensely folded and faulted in the north.

The Salt Range exposes a good sedimentary succession but has a long gap between the Cambrian and the Upper Carboniferous, and short gaps below the Upper Jurassic, below the Eocene, and below the Upper Oligocene. The Saline Series with its associated salt, marl, gypsum, dolomite, and oil-shale beds is exposed all along the Salt Range. The salt beds attain a maximum thickness of 800 feet. The salt appears massive except where it includes marl and gypsum bands which show very complex folding. The Saline Series occupies various stratigraphic positions, and its contacts with the other formations are highly disturbed and brecciated, presumably as a result of thrusting.

The controversy regarding the age of the Saline Series, whether Cambrian or Eocene, will probably not be settled without the aid of new techniques, for the observable geologic features can be used to support either side of the controversy.