This basal layer is overlain by gypsiferous marl, which is covered by interlayered beds of gypsum and dolomite with infrequent seams of oil shale.

The Salt Range is the southern edge of a well-described fold-and-thrust belt, which underlies the entire Pothohar Plateau and developed south of the Himalayas as a result of the ongoing collision between India and Eurasia.

For example, while working with Geological Survey of India in the 1930s and 1940s, Birbal Sahni reported finding evidence of angiosperms, gymnosperms, and insects inside the mine which he regarded as originating from the Eocene period.

[19] The salt reserves at Khewra were discovered when Alexander the Great crossed the Jhelum and Mianwali region during his Indian campaign.

[8] They found the mining to have been inefficient, with irregular and narrow tunnels and entrances that made the movement of labourers difficult and dangerous.

To address these problems the government levelled the road, built warehouses, provided a water supply, improved the entrances and tunnels, and introduced a better mechanism for excavation of salt.

[11] In raw form it contains negligible amounts of Calcium, Magnesium, Potassium sulfates, and moisture; it also contains iron, zinc, copper, manganese, chromium, and lead as trace elements.

[11] It is used for cooking, as bath salt, as brine[30] and as a raw material for many industries, including a soda ash plant set up by AkzoNobel in 1940.

[36] Salt from Khewra mine is also used to make decorative items like lamps, vases, ashtrays and statues,[37] which are exported to the United States, India and many European countries.

[39] Warth introduced the use of a lathe to cut out art pieces from the rock salt, as he found it similar to gypsum in physical characteristics.

[40] In 2008 the Government of Pakistan decided to sell off seventeen profitable organisations including Khewra salt mines,[41] but the plan was shelved.

[33] Khewra Salt Mine is a major tourist attraction, with around 250,000 visitors a year,[7] earning it considerable revenue.

[25] Other artistic carvings in the mine include a replica of Minar-e-Pakistan, a statue of Allama Iqbal, an accumulation of crystals that forms the name of Muhammad in Urdu script, a model of the Great Wall of China and another of the Mall Road of Murree.

A clinical ward with 20 beds was established in 2007, costing 10 million rupees,[43] for the treatment of asthma and other respiratory diseases using salt therapy.

[7][47] More recently the miners won an important environmental case against the mining company for the provision of unpolluted drinking water.