Tertiary Fossils. 



227 



bed. In fact, this theory of the presence of faults along this par- 

 ticular trend line is supported by the parallel system of fractures 

 re-entrant along the coast, stepped in the same direction from the 

 Head of the Bight to Anxious Bay, and even }:>evond. 





r«,0«_ ^ - ->-o 



tie" 



K O S 



-r R ^ »- ' 



O Idtr- 



^4 









O 







r\»«t..%)R«cH 



Fig. 1. Sketch Map of South Australian area including Fowler's Bay an<T 

 the Ooldea Soak. Main details taken from the geological niaj) of South 

 Australia, by H. Y. L. Brown, 1899. 



This shows the trend, in a north-westerly and south-easterly direction, of 

 probable fracture zones, involving the Miocene and Pleistoceuo rocks. The 

 direction of sand-ridges are also seen to be influenced by the underlying^ 

 structure, since, as Mr. Henry Deane, M.A., informs me, they generally run in 

 a similar way. These fracture lines would also appear to have a considerHble 

 bearing on the disposition of water holes, lagoons and soaks in this part of the 

 country. 



Areas in this map marked Granite may also include Metamorphic rocks, as 

 Gneiss, Hornblende and Mica Schists ; also Diabase dykes and mineral yeins. 



The Older Tertiary can be referred to the Miocene, to which the older 

 fossiliferous beds of the Ooldea Soak belong. 



The late Tertiary includes the Older Pleistocene of the Ooldea Soak and all 

 subsequent stages, as Sand-dune rock and Concretionary limestone. 



12 



