Page:Encyclopædia Britannica, Ninth Edition, v. 17.djvu/439

NEW SOUTH WALES deposits, penetrated them, and metamorphosed them in various degrees up to a close resemblance to igneous rocks. The great western plains of the interior are characterized by isolated rocks, or short ranges, mostly granite, but occasionally trap, long sand ridges, and clay basins. The sand and clay both result from the disintegration of granite and trap, the sand ridges having been wind-blown, and the clay washed into the lower levels. Many of the wells sunk into the yellow clay;furnish an almost undrinkable brackish water, from the salts of soda and iron, and occasionally lime, potash, and magnesia, yielded by the felspars. The Upper Silurian rocks occur frequently, but chiefly on the western watershed of the great dividing range. They consist of conglomerates, sandstones, slates, mud- stones, and limestones, and have a general meridional strike. Devonian rocks are displayed on the western flanks of the Blue Mountains. They include sandstones, con glomerates, limestones, and shales, related by their fossils to the Silurian beds below and to the Carboniferous beds above. The Carboniferous series is very widely developed. The strata are probably not less than 10,000 feet thick, the lower beds containing both plants and marine fauna. The Upper Carboniferous series includes the lower Coal- measures of New South Wales. These are traceable along the coast from 31| to 35 J S. The coal-seams are visible above the sea-level from Coal Cliff, 20 miles south of Sydney, the seams rising to the southward, and from Lake Macquarie, north of Sydney, the seams rising to the north ward. The great coal basin extends westward along what seems to have been a depression between the northern and southern elevated portions of the old main range, and, lying under what is now the Blue Mountains, passes up northwards along the western flank of the main range towards the boundary of Queensland. The western edge of the coal basin is not determined. Overlying the coal basin, to the westward of Sydney, is a Mesozoic sandstone formation, 1000 feet thick, while above this, and also inter mixed with it, lies a shale deposit. All these series have been disturbed by dykes of basalt, diabase, and dolerite. Some of the coal-seams have been tilted by this intrusion; in other cases the dip has not been changed ; and in some cases the adjacent coal has been charred into coke. Vol canic disturbance seems to have been very active during the Tertiary epoch, and the igneous formations occupy about 40,000 square milea Minerals. Commercial mining is at present limited to gold, silver, copper, tin, coal, and oil shales. The greater portion of the gold hitherto raised has been from alluvial deposits. These are of Permian, Cretaceous, Tertiary, and Quaternary ages, and are derived from the degradation of the older sedimentary rocks of Upper Silurian, Devonian, and Lower Carboniferous ages. The formations in association with which gold has been found are widely scattered over the colony, and are estimated to occupy nearly one-fourth of its area. In the reefs, gold seldom occurs without one or more of the following sulphides : iron pyrites, galena, mispickel, blende, and copper pyrites. The gold is always more or less alloyed with silver, and there are occasionally traces of copper, iron, osmiridium, and other metals. The greatest depth at which auriferous reefs have been worked is 940 feet at Adelong. The value of the gold raised in the colony up to the end of 1882 was 34,839,847. Silver has been found in several places, but has only been profitably worked at Boorook. The lodes vary in width rom 1 to 3 feet, and are situated in belts of felspar porphyry, alternated -with beds of fossiliferous shales of the Devonian forma tion. The value of silver raised to the end of 1882 was 187,429. Copper ore is traceable on the surface in very many places, and the cupriferous formations are already estimated to cover an area equal to 4,300,000 acres. The value of copper exported to the end of 1882 was 3,538,285. Tin has been profitably worked since 1872, and the value exported to the end of 1882 was 5,173,038. It is nearly all taken from alluvial deposits in the first instance from the beds of existing creeks, but more recently from the beds of old rivers, sometimes covered by basalt. It is all obtained from the Tertiary and Quaternary drifts, composed of the detritus from the stanniferous granite. The area of stanniferous deposits is estimated at 5,440,000 acres, the principal tin-bearing localities being in the high lands of the great dividing chain in the northern and southern districts. The known Coal-measures embrace an area of about 24,000 square miles, the seams varying from 3 feet to 25 feet in thickness. The seams are mostly horizontal. The dip is usually under 5. The principal collieries are near Newcastle, and on the lllawarra coast, and at the western foot of the Blue Mountains. The seams worked to the south of Sydney are more anthracitic than those worked to the north. The value of the coal raised during 1882 was 944, 405. AVhatis called, though erroneously, "kerosene shale" is worked in the west at Hartley and in the south at Joadja Creek. It is really a species of cannel coal. A good illuminating oil is distilled from it, and it is largely shipped for use in gas-works, a moderate percentage of it greatly improving the quality of the gas. The value of this cannel coal raised up to the end of 1882 was 665,160. Iron exists in abundance, and has been worked at Mittagong and Lithgow Valley, but the colonial cost of labour has made it difficult to compete with English imports. Red and brown ore exists in abundance in the sandstone formation. It contains 55 per cent, of metallic iron. Beds of clayband iron ore are found in the Coal-measures, both on the west of the Blue Mountains and on the lllawarra coast. Antimony has been found in several places, and has been slightly worked in the Macleay and Armidale districts, where the lodes traverse sedimentary rocks of the Devonian age. Argentiferous lead is found in many places in the Silurian, Devonian, and granite formations, but hitherto the attempts to work it at a profit have been a failure. Bismuth has been found in the tin-bearing rocks, and asbestos in veins in serpentines ; chromic iron and manganese ore have also been found in consider able quantities. The tin-bearing drifts in the river gravels con tain precious stones, the diamond, sapphire, emerald, ruby, opal, amethyst, garnet, chrysolite, topaz, cairngorm, and onyx having all been found. The colony is veil supplied with building stone, granite, sandstone, flagging, marble, limestone, slate, and fire-clay ; and brick and pottery clays occur in abundance. Agriculture. The fertile soils consist chiefly of the alluvial deposits on the banks of the rivers and the detritus of the igneous rocks. On the rich flats on the banks of the river Hunter, mostly devoted to the growing of lucerne for hay, six cuttings are generally taken off in the year. To the southward of Sydney the coast land is very largely devoted to dairy-farming, the herbage being rich and sweet, especially in localities where there has been any basaltic overflow. The principal supply of butter and cheese for the Sydney market comes from this district. Along the coast to the north ward of Port Stephens maize is very largely cultivated for horse- food. The yield in an average season is about 50 bushels per acre. Sugar has not been commercially successful south of Clarence. But on that river, and on the Richmond, and all the way to the border of Queensland, it has proved profitable, and is rapidly extending. Oranges are not cultivated to advantage south of Sydney, but any where to the northward along the eastern slopes they grow freely. Nearly every description of European fruit is cultivated without difficulty. Tobacco is increasingly grown both on the coast and on the alluvial flats of the western waters. In earlier days wheat was very largely grown upon the coast, but in consequence of the rust this crop has been driven inland on to basaltic areas. The produc tion of wine is limited only by the demand. Hitherto the principal seats of this industry have been in the Hunter river district, where many varieties of light wine are produced, and in the district round Albury, where, in a dry, warm climate, and from a rich volcanic soil, a strong, full-bodied wine is obtained. Grazing was the beginning of the industrial life of Australia, and it is still the great source of its wealth. The mildness of the winter allows stock to be pastured out of doors all the year round, and supersedes the necessity of artificial food. The consequence is that the country has been easily and rapidly overspread with sheep and cattle farms, the only natural check being the want of water in the remote parts and the occasional discouragement of poor markets. The speciality of the Australian wool is its fineness, and the small merino sheep are found to be the best-suited to the pasture and the climate. The stock which is now most appre ciated is that of Australian breeders who have kept their nocks free from intermixture for a long period. The Australian merino has established for itself a separate type. Sheep as a rule are remarkably healthy in the Australian climate. In wet seasons and on stiff land they are liable to fluke and to foot-rot. Scab has occasionally appeared ; but the precautions taken against it now are very strict, and it has not prevailed in the colony since it was stamped out in 1866. Cattle are liable to pleuro-pneumonia, which is sometimes very destructive. Flora. The flora of New South Wales, which comprises about 3000 species of plants, exclusive of mosses, lichens, fungi, and sea-weeds, is characterized by many peculiar forms. The great orders of dicotyledonous plants on the eastern side of the dividing range are respectively Lcyuminosse, Composite, Myrtacese, Pruteaceas, Epncridcse, and Rutoccx, three of which (the Myrtaccw, Protiacae, and Epacridcae) include the great majority of the trees and shrubs which differ so essentially from the ordinary European types. XVII. 52