jnorainic obstructions to drainage. The only alteniatives* 

 are to assume the action of either wind erosion or chemical 

 solution, and I am disposed to' think that both these agents 

 have played their part in producing the unique physical fea^ 

 tures of the district. 



Geological Features of the District, 



In a pravious paperf the present writer has described some of 

 the geological characteristics of the country under considera- 

 tion. The geological formations occur, as shown in the follow- 

 ing table : — 



Rectat. — :Blcwn sands. Dolomitic travertine. Saline de- 

 posits. 



Post Tf.rtianj. — Calciferous shelly sands (raised sea bed). 

 Natural whiting. 



Pliocene or Miocene. — Mottled and variegated clays. (Dry 

 land conditions). 



Eocene. — Fossiliferous limestone (marine). 



Pre-Tertiary. — Glacial sands, till, and boulders showing ice 

 action. 



Archaean. — Metamorphic and granitic. 



The highly metamorphic and granitic rocks are visible only 

 at certain points on the coast, and fonn the prominent head 

 lands. The geology of the inland portions of the district i3 

 limited to such formations as shown in the table, which overlie 

 the Archaean, and each member of these newer formations 

 bear evidence of extensive waste. Thus, on the west side 

 of Troubridge Hill, on the south coast, and at Point Turton, 

 on the north coast, the Eocene limestones occur between the 

 glacial beds and the Travertine limestone of the district, but 

 at many points on the coast, as well as over the gi'eater part 

 of the inland country, the Eocene is absent, and the recent 

 travertine beds rest directly on the glacial deposits. 



That the Eocene beds at one time covered most, if not all, 

 the southern portion of the Peninsula, may be inferred from 

 the number of outliers of this formation, which can be noted 

 scattered over tlie area. 



The following occurrences of the Eocene beds were either 

 directly observed by the ,writer or given on information re- 

 ceived from trustworthy sources : — 



* The advocates of marine erosion might assume that the lagoons were 

 originally coastal bays that, on the retreat of the sea, became converted 

 into lakes through sand bars being thrown across their outlets. But this 

 is inadmissible ; first, because no marine shore banks exist in such situa- 

 tions, and, further, the physical features of the lagoons are entirely 

 opposed to such a theory. 



t Trans. Roy. Soc. S. Aus., vol. XXIV. (1900), p. 71. 



