The overwhelming majority of the people live in the belt of high lands and coastal lowlands which stretch northwards from Encoun ter Bay and Jervis Peninsula to the lat. of Port Augusta and rather beyond. Yorke Peninsula and south-east Eyre's Peninsula, and the Murray River valley are comparatively well-peopled ; the "South-East," parts of the "Mallee" country (south of the Mur ray) and the north-west coastal parts of Eyre's Peninsula have a fair but relatively isolated amount of settlement. The great in terior, though partly pastoral, contains very few people.
Of the total area of the State only 7% has been alienated (1927-28), some 49% is held under lease and licence (42%, 2 5 9, 3oo sq. miles, under pastoral lease) and 44% is unoccupied. The total production (1926-27) was valued at £41,154,000 (£73 13s. per head) to which agriculture contributed c. 116,635,cm; manu factures, 113,100,000; pastoral industry, £6,128,000; dairying, poultry, etc., £2,928,000; mining, £1,032,000 (1927: £1,189,000). Moreover, in 1921, 12.83% of the total population was classed as "industrial," 10.60% as "primary producers," 10.59% as engaged in transport and commerce. Discernible in these figures are: (a) The overwhelming importance of the "gulf" area—lowlands and highlands—containing the capital city (manufactures, commerce) with its surrounding agricultural and dairying districts, Port Pirie (q.v.) with its metallurgical industry and the largest continuous areas of agricultural production. (b) The relatively sparse popu lation and secondary position of the northern areas with their pastoral industry. (c) The relative unimportance of mining.
In the northern areas—i.e., the 280,00o sq. miles lying north of c. lat. 31° S. (v. sup.)—the chief geographical determin ant is the climate with its high summer temperatures, large annual and diurnal range, and its small and very erratic rainfall (v. sup.). These lands are, and will probably long remain, pastoral areas, capable of improvement through water-conservation, pasture cul tivation and control of rabbits and dingoes, but never perhaps of more than second or third rate quality. The western half is only now being slowly occupied. Recent reconnaissance and well sinking seem to indicate wide-spread underground (shallow) water-supplies, and stock-routes (with wells) have been established from the Musgrave Range to the central railway line at Warrina (south of Oodnadatta) and from Coward, on the same line, south-west to Wilgena on the transcontinental line. The east (Lake Eyre Basin) is better known and more developed, and contains scattered cattle and sheep stations—besides a mission station—with their artesian wells. These lie mainly along the lines of railway and the two other main stock-routes—(Marree Diamantina River–Birdsville, and Hawker or Farina [on central railway]—Strzelecki Creek–south-west Queensland, respectively) —which branch north-north-west and north-north-east respec tively from near the head of Flinders Range and serve to bring stock from as far as Central Australia and south-west Queensland to their markets in the south. Some 8o,o0o-9o,000
cattle and 890,00o sheep are carried normally—the latter mainly in the north-east—but the density per square mile is low.
The second division includes the central highlands and part of their eastern spur (the Flinders-Barrier Range "bridge"). But between these and the eastern boundary of the State lies a strip (lats. 30-34° S.) which might, not inappropriately, be termed the "Eastern Interior," since in respect of climate (large temperature range; rainfall under io in.) it more resembles the northern interior and is devoted almost exclusively to pastoral pursuits (cattle and sheep). The coastal zone is the best developed portion of the State and comprises nearly all the mineral deposits so far worked, a large part of the agricultural, dairying and manufac turing areas and sites, besides the capital city and nearly all the larger towns and important parts of the State. The mineral out put is at present relatively small. The copper areas, notably those of the Moonta-Kadina field, though they probably still contain valuable reserves, have virtually ceased production. Their annual output (1916-20) alone averaged i600,000, whereas in 1927 the total copper production of the State was valued at L12,500. The iron-ore is practically inexhaustible; the Iron Knob area north west of Spencer Gulf, at present vigorously exploited and the ore exported from Whyalla (1927: £831,000, see AUSTRALIA : Minerals, and Metallurgy). The State possesses perhaps upwards of 7o,000,000 tons of available coal but much of this is of soft (sub-bituminous) and rather poor quality (high sulphur con tent) and unfavourably situated. Valuable clays and build ing stones abound, and the salt and gypsum deposits are the largest and best in Australia, are easily worked and serve as a basis for industrial developments (alkali and chemical industry). Deposits of salt occur on Yorke Peninsula (Yorke Town, with port at Edithburgh), at Lake Macdonnell, near Fowler's Bay (Bight) (2,500,000 tons salt ; gypsum, 70,000,00o tons), and near Port Wakefield. The high temperatures (net evaporation : 30-8o in). and semi-enclosed (high-salinity) waters of the gulfs also facili tate salt-production by evaporation. Some 18,000,000 tons of reserves of salt exist ; the output (1927) was valued—salt: 178,400 ; gypsum : L82,000.