143 



The South Australian areas where lignite beds have been 

 proved belong to one or other of two main regions of Tertiary 

 sedimentation. Of these, one is Gulf St. Vincent and its, 

 borderlands; to this the Clinton, Paradise, and Noarlunga 

 occurrences are to be referred. The other is the great Murray- 

 Gulf, so marked a feature of Tertiary times in Australia, 

 when a shallow sea extended all over the south-east lands of 

 South Australia, part of Victoria, and even reaching well 

 into New South Wales territory. Bower and Moorlands 

 belong here. The published results of the Government bores 

 indicate that the lignite beds of the Gulf St. Vincent area 

 are embedded in, and entombed beneath, strata of a more 

 sandy nature than is the case on the Murray side, where very 

 fine clayey and calcareous silts are a greater feature. This 

 is no doubt attributable to muddy waters delivered to the 

 latter area by the great ancestor of the present Murray- 

 Darling system. 



In this connection there is some ovidenoe indicating 

 that, in all probability, the brown coal of the Gulf St. 

 Vincent region may reach a greater degree of freedom 

 from ash than that influenced by the muddy waters of the 

 ancestral Murray. So' far as at present explored, this is the 

 case, as can be noted by a comparison of the seams at Moor- 

 lands with those at Clinton. The Mines Department Records 

 give composite analyses (^i) of all lignite beds met in all bores 

 to date, respectively, in each of thes fields as follows: — 



Moorlands. Clinton. 



Moisture at 105° C. ... 51*41 51*47 



Volatile matter ... 21*38 24*29 



Fixed carbon 13*82 15*16 



Ash 13*39 9*08 



100*00 100*00 



Sulphur content ... 2*66 2*01 



Average moisture after 



air-drying ... ... 15*74 16*94 



In arriving at these figures the Government Geologist, 

 Mr. L. K. Ward, differentiates the carbonaceous beds as 

 follows : — 



"Lignite" is such as contains not less than 24 per cent. 



of ash. 

 ''Lignit-e with clay" is the designation for beds contain- 

 ing between 24 and 50 per cent. ash. 

 ''Clay with lignite" distinguishes beds containing over 

 50 per cent. ash. 



(11) Includes Bores 1 to 34, at Moorlands ; and 1 to 4, at 

 Clinton. 



