Page:A sketch of the physical structure of Australia.djvu/63

51 (called Moorundee) to Adelaide, Captain Sturt (p. 32) says, "I turned from the river to the westward, along the summit of the fossil formation, which at a distance of a few miles was succeeded by sandstone, and this rock again as we gained the hills by a fine slate, and this again, as we crossed the Mount Barker and Mount Lofty ranges by a succession of igneous rocks. On descending to the plains of Adelaide, I again crossed sandstone and to my surprise discovered that the city of Adelaide stood on the same kind of fossil formation I had left behind me on the banks of the Murray." Here I can again speak from personal observation. About ten miles south of Adelaide, the flanks of the chain of hills, which from Cape Jervis northward had been washed by the sea, begin to recede from the coast, and let in a low plain between them and the water. This plain increases in breadth to the northward, till about Adelaide it is ten miles wide, and appears to be still wider towards the head of the gulf of St. Vincent. It consists entirely of the tertiary formation, patches of which are said to occur here and there among the hills at a much greater elevation, but these I did not see.

Around Adelaide the formation is well shewn in several quarries. In the higher parts of the town, immediately below the surface, is found a light yellow concretionary limestone, forming a thin bed, below which is a white clay, and below that, sand, with other beds of stone. These latter are seen in a quarry at the back of Government House, on the bank of the Torrens,