BY A. B. AVALKOM. 83 



The Hawkesbury Series is divided into tbi-ee Stages, viz. : — 

 Xarrabeen, Hawkesbury Sandstone, and Wianamatta. in ascend- 

 ing order. The Narrabeen Stage consists mainly of sandstones 

 and shales, the Hawkesbury Stage of massive sandstones char- 

 acterised by current-bedding, and the Wianamatta Stage mostly 

 of shales. 



This Series comprises a basin, and is apparently conformable, 

 in the central portion of the basin, with the underlying Permian 

 (Permo-Carboniferous) System; but, in the marginal areas, there 

 is an overlap amounting to unconformity. The Hawkesbury 

 Sandstone Stage rests conformably on the Narrabeen Stage, 

 while the Wianamatta Stage occupies a slightly eroded basin in 

 the Hawkesbury Sandstone.* 



The Talbragar Beds cover only a small area, and occupy a 

 basin eroded in the Hawkesbury Sandstone; and there is no 

 doubt of an unconformity, stratigraphical as well as palseonto- 

 logical, between the Hawkesbury Sandstone and the Talbragar 

 Beds. 



The Clarence Series occurs in the north-east of New South 

 Wales, between the New England Tableland and the coast; and, 

 at its northern end, it is continuous with the Walloon Series of 

 Queensland. Reference to the latest Geological Map of New 

 South Wales shows that the Clarence Series is practically con- 

 tinuous with the Walloon Series in the neighbourhood of Mt. 

 Lindsay, and also that, further west, it is continuous with the 

 eastern branch of the belt of Walloon Series on the Darling 

 Downs, extending through Warwick and Killarney to the border 

 of New South Wales. 



The Artesian Series of New South Wales exists on the western 

 margin of the New EngLind Tableland, and extends along the 

 eastern margin of the Great Australian Artesian Basin. It is 

 practically continuous into Queensland with the belt of Lower 

 Mesozoic rocks extending past Warwick and Toowoomba. It is 

 seen, then, that the Clarence Series and Artesian Series are each 

 directly connected with the belt of Walloon Series in the Darling 



" See Carne, N.S.W. Handbook, B.A.A.S.. 1914, pp. 601 -607. 



