74 



Northern Coast. 



Point Turton. — An interesting geological section was found 

 at Point Turton, situated on the shores of Hardwicke Bay, 

 about six miles in a north-westerley direction from Warooka. 

 The cliffs present a good face of rock as the Eocene limestone, 

 of which the cliffs are chiefly composed, have been quarried 

 for flux. The section that is exposed near the jetty is a 

 very remarkable one, as it embraces no less than four distinct 

 geological formations separated by three lines of uncon- 

 formability. 



The following is the order of occurrence : — 



1. Recent — Travertine limestone, variable in thickness 



up to ... ... .. ... ... ... 20 feet 



( Reddish, mottled clay, preserved in 



2. Miocene — -l eroded hollows of lower Tertiary 



limestone; thickness nil to... ... 20 " 



o p /'Pink-coloured fossiliferous limestone ; 



\ variable in thickness up to ... ... 35 " 



, D m *- [Boulder clay, with glaciated erratics; 



/A? • 7\ \ thickness unknown ; exposed above 

 {Glacial)- y lowwater V 1B „ 



The Miocene clay is best seen at a spot about a hundred 

 yards west of the jetty, and has been preserved from denuda- 

 tion through occupying an eroded trench in the Eocene lime- 

 stone, the latter having been nearly cut through by the 

 eroding agents. 



The Eocene limestone of the section is, as a whole, an ex- 

 tremely compact and pure carbonate of lime. It has been 

 subjected to considerable alteration and reconstruction in 

 situ, a secondary deposit of calcium carbonate having been 

 precipitated within the interstices of the fossiliferous bed' 

 imparting to it a greater compactness. In some places most 

 beautiful slabs of polyzoal stone, with the fronds weathered 

 into strong relief, can be seen. The great purity of the 

 stone makes it valuable as a fluxing agent. 



The Eocene beds rest unconformably on the eroded surface 

 of the glacial clay, the line of junction being very sharp. 



The boulder clay is exposed for some distance in a variable 

 thickness up to fifteen feet, and passes below sea level. The 

 varying thickness of the bed is evidently the result of subaerial 

 waste that took place in pre-Tertiary time-. >efore the old 

 land surface was submerged by the Eocene <^a. The clay 

 is very compact, except where it is subjected to wave action 

 below high-water mark, and even in that position it main- 

 tains a good hard floor that can be walked < \ r without dis- 

 comfort. 



