compression, which finds its westerly limit in the echeloned folds between the Hindu Kush and Lake Baikal, and is continued up to the Bering Straits, whilst the eastern limit is formed by the bulging forms of the coast with the East Asiatic festoons of islands.
According to our assumption, the east coast of India directly adjoined the west coast of Australia. The former also displays an abrupt fracture of the plateau of gneiss, which only suffers an interruption in the narrow trough-like Godavari coalfield, composed of Lower Gondwana strata. Along the coast the Upper Gondwana beds lie unconformably on their edges. A platform of gneiss, with a rolling surface similar to that of India and Africa, is also found in West Australia. Along the coast it dips towards the sea with a long precipitous slope—the Darling range and its northern extension. In front of the steep slope is a depressed flat strip of land built of Palæozoic and Mesozoic strata which is cut through by basalt in a few places. In front of this again is a narrow strip of gneiss which occasionally disappears. On the River Irwin the strata are also coal-bearing. The strike of the folding of the gneiss in Australia is usually directed in a meridional direction, and would be converted to north-east and south-west when joined to India, and therefore parallel with the principal trend-line there.
In the east of Australia the Cordilleras, mainly folded in the Carboniferous, run from south to north along the coast, and terminate in echeloned folds which retreat successively westwards, and individually always run approximately north to south. This, as in the echelon of folds between the Hindu Kush and Lake Baikal, shows the lateral limit of the compression; the gigantic Andean folding, commencing in Alaska and traversing four continents,[1] reaches its end here.
- ↑ North and South America, Antarctica and Australia.
