BY A. B. WALKOM. lOl 



panying the intrusion of extensive granitic masses at the close 

 of the Palaeozoic era. It is impossible to define these latter 

 areas at present, but they include the Stanthorpe and Gympie 

 districts, and probably some of the present coastal portions of 

 Queensland north of Rockhampton. 



The area over which deposition of the Walloon Series took 

 place extended into New South Wales and South Australia; and 

 its boundary probably agreed fairly closely with the margin of 

 the Great Australian Artesian Basin; it is from sandstones in 

 the Walloon Series and its equivalents, that the great bulk of 

 the artesian water is obtained, so that, although these are not 

 known to outcrop along the southern margin of the Artesian 

 Basin, their presence is known, and they are apparently over- 

 lapped by the J^ower Cretaceous strata. 



It may be remarked here, that it is only comparatively recent 

 work that has shown the sandstones forming the intake in 

 Queensland to be of Walloon age. In view of this, it is possible 

 that outcrops on the southern and western margins of the Basin 

 may, in the future, be shown to be of the same age, though at 

 present mapped as Cretaceous. 



The Clarence Series represents deposition in the south-eastern 

 portion of the same basin. The Talbragar beds seem to repre- 

 sent depo.sition in a small, isolated lake. 



In South Australia, the small, faulted basin at Leigh's Creek 

 probably represents an outlier of the main occurrence further 

 north. 



Contemporaneously with the Walloon Series also, there were 

 deposited the Jurassic sandstones, etc., of South Gippsland, Cape 

 Otway, and the Wannon River areas in Victoria, and possibly 

 also portion of the Lower Mesozoic strata of Tasmania. At the 

 same time, marine sediments were laid down in Western Aus 

 tralia, and, associated with these, there are a few plant-remains. 



The close of the Jurassic in Australia was not marked by any 

 violent movement. In Queensland, New South Wales, and 

 South Australia, the Jurassic rocks are followed by Cretaceous 

 marine strata (Rolling Downs Series) without any observable 

 unconformity. Palseontologically, however, there is a very 



