ARTESIAN WATER IN NEW SOUTH WALES. 291 



Gulf of Carpentaria, in the direction of the present course of the 

 Darling-Murray has not yet been definitely settled, owing to the 

 thick covering of Tertiary beds, which completely hide from view 

 the Cretaceous sediments from Dunlop Station, between Bourke 

 and Wilcannia, to the mouth of the Darling-Murray. 



With regard to the possible former extension in this direction 

 of the Cretaceous Ocean my late colleague Mr. William Anderson 

 remarks* : — " Between Bourke and the Barrier Ranges there 

 occur at intervals series of isolated north and south ridges formed 

 of Silurian and Devonian rocks, which crop out through the 

 Cretaceo-Tertiary plains. It is more than probable that, some- 

 where in the area just mentioned, the Tertiary beds overlie and 

 thin out northwards over the southern edges of the Cretaceous 

 strata, because in a bore on Dunlop Station, between Bourke and 

 Wilcannia, fossils have been identified by my colleague, Mr. B,. 

 Etheridge, as being undoubted Cretaceous forms, while at Lake 

 Speculation, near Menindie, fossiliferous beds occur, from which 

 fossil leaves have been obtained of Tertiary age. It is therefore 

 reasonable to suppose that such an overlapping of the two forma- 

 tions occurs — the Tertiary plains being continuous in a northerly 

 direction with the Cretaceous plains of Queensland, unless indeed 

 Palaeozoic ground having an east and west trend exists, which 

 does not come to the surface, but which would produce a shoaling 

 of the Tertiary formation on its southern side, and of the Cretace- 

 ous formation on the north side of it. It is just possible however 

 that the superficial clays met with in the Dunlop bores, and passed 

 through before meeting with the Cretaceous beds in many wells 

 towards the Queensland border may represent the thinning out 

 northwards of the Tertiary formation." All that can be said 

 definitely at present, is, that as far as at present proved no Cre- 

 taceous fossils have been found along the tract of country described 

 following the course of the Darling-Murray, anywhere to the south- 

 west of Dunlop Station. It is just possible therefore that the 

 Cretaceous Ocean covering the central portions of Australia was 



* Ann. Report Depart, of Mines, 1891, in lit. 



