Page:A sketch of the physical structure of Australia.djvu/70

58 He frequently mentions the fossil shells, and describes them as of recent aspect. At the top of the cliffs the country is sometimes said to be covered with recent freshwater spiral shells, but as Mr. Eyre apparently does not pretend to be a conchologist, their freshwater origin may be doubted. He also speaks of places where the surface was strewed with broken flints like gun flints. These are probably the same as the angular pieces of quartz mentioned by Sturt as occurring in some parts of his central desert. Beyond (or to the westward of) the head of the Bight, the same formation was in the upper part brown, in the lower white, and in long. 129&deg; the brown was found to be a coarse grey limestone with a few shells, very hard; the white a gritty chalk full of broken shells and marine productions, with horizontal layers of flint, six to eight inches thick. The lower white or chalk part was often worn away, and the upper brown overhung in crags with fallen fragments on the beach below.

Beyond long. 126&deg; we get this section:
 * 1) An upper crust of oolitic limestone with shells.
 * 2) Coarse grey hard limestone.
 * 3) Alternate strata of white and yellow limestone in horizontal layers.

In approaching Mount Rugged, granite was again met with. Throughout this extent of 600 miles, Mr. Eyre always mentions the summit of the cliffs as stretching away into the interior in apparently