Volume 14 Australasia - dana ward's homepage

358 AUSTRALASIA.New Zealand orographic systems, and are surpassed even by the mountains of theSolomon Archipelago. This circumstance strengthens the hypothesis, according towhich Australia forms a single geological unit with the lands uovv scattered to thenorth and east.New Guinea, Melanesia, and New Zealand would thus be nothingmore than the margin of the primitive Austral continent, over half of^hich now liessubmerged beneath the intervening shallow seas. Numerous examples of similarformations occur elsewhere, as in South America, in Africa, and, in a general way,round the great Oceanic basin from the Cape of Good Hope to Cape Horn, wherethe loftiest crests also rise immediately above j)rofound marine abysses.Physical Features.— Mountain Systems.As in other Australasian regions, the highest mountains on the mainland occurin the neighbourhood of the seaboard and on the side facing the deep Pacificwaters. The chief continental crests are disposed in such a way as to form anouter crescent sweeping round from York Peninsula to Wilson's Promontory,over against Tasmania. Beyond this elevated rim the land falls so uniformly usto suggest to the early explorers the existence in the interior of a " Caspian "dejiression, into which flowed all the surrounding .streams. But instead of thisimaginary central sea there exists nothing beyond a few small basins without anyoutflow, while nearly all the important rivers flow directly to the coast. Neverthelessthe plains traversed by them stand at a very low level, in consequence- ofwhich disposition of the land the seaboard has been excavated far into the interiorboth on the north and south sides, where have been respectively developed theGulfs of Carpentaria and Saint Vincent. Between these two indentations, whichare the largest on the whole continental perijahery, the intervening plains scarcelyanywhere exceed an altitude of 500 feet above sea-level. West of this depressionthe surface again rises, and towards the centre of the continent several of thesummits exceed 3,000 feet in elevation.The chief range, known as the Australian Alps, begins in Victoria, and afterpresenting its convex side towards the South-east, trends round to the left and iscontinued by other chains northwards. The Yass, a headstream of the Murray,is regarded as the northern limit of the Australian Alps proper, which have a totallength of about 250 miles. These highlands deserve the name of Alps less fortheir altitude than for the large number of their collective groups, spurs, offshoots,lateral or parallel ridges. They are almost everywhere of easy access, the mostrugged escarpments being usually situated about midway between baseand summit,while higher up the slopes are more gently inclined, and extensive grassy orsparsely wooded plateaux form the pedestal of domes and crests which may beascended even on horseback. The culminating peak, Mount Townshend, in theKosciusko group. New South Wales, attains a height of 7,350 feet.In many of these upland valleys the snows never melt, and in winter fromMay to November even the plateaux remain shrouded in a white mantle. A fewneves are found in the higher ravines of the Kosciusko Mountains, and traces ofancient glaciers in various parts of the range. In the Bogong Hills (6,630 feet),