85 



effects of the wind. The wind works around the hardened crust 

 until it scoops out a conical hill 30 or 50 feet high, as in the 

 case of one very conspicuous height of this kind amongst the 

 Brecknells, known as the "Pyramid." We struck the coast at 

 an unnamed but interesting bay about four miles east of Nobby's 

 Island. The headlands of this bay are bold and extremely 

 rough, especially those on the west side, which rise to a height of 

 100 feet, and gradually slope towards the point. The headlands 

 are entirely composed of recent or pleistocene deposits. Succes- 

 sive layers of travertine limestone, interbedded with more or less 

 indurated blown sands, are exposed in the face of the cliffs, the 

 weathering of the sand-rock showing very strikingly the lines of 

 oblique lamination arising from its mode of origin. 



Near tiie extremity of the western headland, only accessible 

 at low water, is a natural arch cut out by the sea about 20 feet 

 in height, with an eagle's nest occupying the top near the centre 

 of the arch. Passing under the arch, access was gained to a 

 very secluded cove, in which the structure of these terial deposits 

 exhibited some remarkable and instructive features. There are 

 few places, if any, in the world where sand dunes occur in such 

 magnitude, or could be more effectively studied, than along the 

 south coast of Kangaroo Island. 



The existence of such an enormous amount of sea-worn sand 

 raises the question of its origin. The present limited coast line 

 of Kangaroo Island seems disproportionate and inadequate for 

 the accumulation of such a vast amount of waste material. Many 

 things point to the former existence of a great mountain range 

 to the south of the continent, as already suggested, and which is 

 now represented only by the granitic zone on the southern sea- 

 board, which is to a great extent submerged. The south coast of 

 Kangaroo Island would be on the northern flanks of this lost 

 mountain range, and it is possible that the extensive accumula- 

 tions of sand along the south coast may be the remains of the 

 waste of what was once the main watershed of the southern 

 portions of South Australia. 



The great thickness of the recent and pleistocene beds entirely 

 obscures the palaeozoic rocks of the country traversed, but beach 

 pebbles of the softish palaeozoic quartzite, already described as 

 outcropping inland, suggests the close proximity of this rock. 



A black flint with white coating, very characteristic of the 

 Eocene limestones of the south-east of the State, was picked up 

 on the beach within the bay, which may have been derived from 

 beds of this age not far distant. 



Evidences of a raised sea beach were obtained at the Breck, 

 nells, on the south coast, where a white travertine limestone 

 thickly studded with marine shells, occurred in slabs a few feet 

 above high-water mark. 



