Volume 14 Australasia - dana ward's homepage

NEW ZEALAND—SOUTH ISLAND. 427by the sedimentary matter washed down with the mountain torrents. Withoutcounting numerous sparkling ponds or tarns less than a square mile in extent,South Island contains about sixty basins, some of which cover an area of over 40square miles and fill cavities 300 feet and upwards deep. Nearly all these greatreservoirs are grouped in the southern part of the island and on the east slope ofthe mountains. Rising abniptlj' above the western seaboard, the New Zealand Alpshave too precipitous a slope on this side to allow the running waters to collect inlarge basins. But the opposite decKvity and the plains stretching thence to theeast coast present numerous depressions where the glaciers have been replaced bylakes, most of which have been formed in the intermediate zone between theuplands and the plains. A straight line drawn across the chief flooded basinsfrom north-east to south-west for a distance of about 200 miles would run parallelto the main Alpine chain, and would represent the direction of the axis of thesouthern island.The northern group of lakes east of the highest section of the Alps appears tobe merely the remains of a labyrinth of inland waters, which formerly occupiedthe vast llackenzie Plains, and which are now disposed in countless secondarycavities by moraines, heaps of erratic boulders, dams and sedimentary dejDosits.These basins—Te Kapo, Pukaki, Ohau—were formerly much deeper, and are nowrapidl}' silting up, just as those farther north have already been filled in whichwere at one time traversed by the river Walmakariri. The dav may be predictedwhen the glacial waters of the Waitaki, which now issue in a crystal stream fromthe flooded depressions, will roll down in a tiu'bid current to the plains. Althoughits course scarcely exceeds 120 miles in length, the Waitaki is none the less a greatriver, according to W. N. Blair five times more voluminous than the Thames,although this writer gives no data in support of his statement.*Farther south the Clutha, which receives the overflow of the central gi-oup oflakes, is a much larger watercourse, being compared by the same author with theNile. It is certainly the first river in New Zealand both for size and A'olume, itscatchment basin exceeding 8,000 square miles in extent. The Clutha has alsobeen more thoroughly explored than any other stream in South Island, thanks tothe rich gold-fields, which since the year 1862 have attracted thousands of minersto the region about its headwaters. "Wakatipu,' one of the lakes belonging to thissj'stem, is no less than 50 miles long, but only from 1 to 3 miles wide. It thuspresents the aspect of a winding river, without visible current, with a mean depthof no less than 1,200 feet, and in its profoundest chasms sinking to 1,400 feet.both sides the encircling hills jjlunge abruptly into these abysmal watci's.Te Anau, largest of all New Zealand lakes, lies beyond the Clutha basin at thehead of the Waiau, a short stream flowing to the south coast. The lake fills a longvalley and several tributary branches for a space of 140 square miles, and in itsdeepest part the soimding line has measured 940 feet. Te Anau is separated by anarrow isthmus from Manapuri (ilanipori), another lacustrine basin, which is alsosaid to be very deep, and which branches into numerous creeks and buys, winding* Scottish Geographical Magazine, Xovemlier, 1887.On