complete record of the gradual
changes that came over the marine fauna of Tethys than any other area of
the kind known. One must pass over the great number of interesting
features still left unmentioned, including the grand architecture of the
Sub-Himalaya and the diversity of formations in different parts of the
Frontier Province; for the rest of the available space must be devoted
to a brief reference to the minerals of value.

~Rock-salt~, which occurs in abundance, is possibly the most important
mineral in this area. The deposits most largely worked are those which
occur in the well-known Salt Range, covering parts of the districts of
Jhelam, Shahpur, and Mianwali. Near the village of Kheora the main seam,
which is being worked in the Mayo mines, has an aggregate thickness of
550 feet, of which five seams, with a total thickness of 275 feet,
consist of salt pure enough to be placed on the table with no more
preparation than mere pulverising. The associated beds are impregnated
with earth, and in places there occur thin layers of potash and
magnesian salts. In this area salt quarrying was practised for an
unknown period before the time of Akbar, and was continued in a
primitive fashion until it came under the control of the British
Government with the occupation of the Panjab in 1849. In 1872 systematic
mining operations were planned, and the general line of work has been
continued ever since, with an annual output of roughly 100,000 tons.

Open quarries for salt are developed a short distance to the
east-north-east of Kalabagh on the Indus, and similar open work is
practised near Kohat in the North West Frontier Province, where the
quantity of salt may be regarded as practically inexhaustible. At
Bahadur Khel the salt lies at the base of the Tertiary series, and can
be traced for a distance of about eight miles with an exposed thickness
of over 1000 feet, sometimes standing up as hills of solid salt above
the general level of the plains. In this area the production is
naturally limited by want of transport and the small local demand, the
total output from the quarries being about 16,000 tons per annum. A
small quantity of salt (generally about 4000 tons a year), is raised
also from open quarries in the Mandi State, where the rock-salt beds,
distinctly impure and earthy, lie near the junction between Tertiary
formations and the older unfossiliferous groups.

~Coal~ occurs at numerous places in association with the