North Western State Railway, but the maximum output in any one year never exceeded 14,000 tons, and in 1900, owing to the poor quality of material obtained, the collieries were closed down. Recently, small outcrop workings have been developed in the same formation further west on the southern scarp of the Salt Range at Tejuwála in the Sháhpur district.
Gold to a small amount is washed from the gravel of the Indus and some other rivers by native workers, and large concessions have been granted for systematic dredging, but these enterprises have not yet reached the commercially paying stage.
Other Metals.—Prospecting has been carried on at irregular intervals in Kulu and along the corresponding belt of schistose rocks further west in Kashmír and Chitrál. The copper ores occur as sulphides along certain bands in the chloritic and micaceous schists, similar in composition and probably in age to those worked further east in Kumáon, in Nipál, and in Sikkim. In Lahul near the Shigrí glacier there is a lode containing antimony sulphide with ores of zinc and lead, which would almost certainly be opened up and developed but for the difficulty of access and cost of transport to the only valuable markets.
Petroleum springs occur among the Tertiary formations of the Panjáb and Biluchistán, and a few thousand gallons of oil are raised annually. Prospecting operations have been carried on vigorously during the past two or three years, but no large supplies have so far been proved. The principal oil-supplies of Burma and Assam have been obtained from rocks of Miocene age, like those of Persia and the Caspian region, but the most promising "shows" in North West India have been in the older Nummulitic formations, and the oil is thus regarded by some experts as the residue of the material which has migrated from the Miocene beds that probably at one time covered the Nummulitic formations, but have since been removed by the erosive action of the atmosphere.
Alum is manufactured from the pyritous shales of the Mianwálí district, the annual output being generally about 200 to 300 tons. Similar shales containing pyrites are known to occur in other parts of this area, and possibly the industry might be considerably extended, as the annual requirements of India, judged by the import returns, exceed ten times the native production of alum.
Borax is produced in Ladákh and larger quantities are imported across the frontier from Tibet. In the early summer one frequently meets herds of sheep being driven southwards across the Himalayan passes, each sheep carrying a couple of small saddle-bags laden with borax or salt, which is bartered in the Panjáb bazars for Indian and foreign stores for the winter requirements of the snow-blocked valleys beyond the frontier.
Sapphires.—The sapphires of Zánskar have been worked at intervals since the discovery of the deposit in 1881, and some of the finest stones in the gem market have been obtained from this locality, where work is, however, difficult on account of the great altitude and the difficulty of access from the plains.
Limestone.—Large deposits of Nummulitic limestone are found in the older Tertiary formations of North-West India. It yields a pure lime and is used in large quantities for building purposes. The constant association of these limestones with shale beds, and their frequent association with coal, naturally suggest their employment for the manufacture of cement; and special concessions have recently been given by the Panjáb Government with a view of encouraging the development of the industry. The nodular impure limestone, known generally by the name of kankar, contains sufficient clay to give it hydraulic characters when burnt, and much cement is thus manufactured. The varying composition of kankar naturally results in a product of irregular character, and consequently cement so made can replace Portland cement only for certain purposes.
Slate is quarried in various places for purely local use. In the Kángra valley material of very high quality is obtained and consequently secures a wide distribution, limited, however, by competition with cheaply made tiles.
Gypsum occurs in large quantities in association with the rock-salt of the Salt Range, but the local demand is small. There are also beds of potash and magnesian salts in the same area, but their value and quantity have not been thoroughly proved.
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