556 president's address. 



up of this outlet to have taken place, through the subsidence of the 

 land, or any other cause, the water not having any vent to escape 

 by, would accumulate in the porous strata until under sufficient 

 pressure to force its way to the surface along cracks or through 

 holes caused by such pressure, and bring with it the sand, in a 

 similar manner to the present mud and sand springs. The eruption 

 of sand in large quantities would cause a subsidence of the sur- 

 rounding area, whereof there is evidence in the valleys of the Coopei 

 and Diamentina, and thus have created the great lakes into which 

 these rivers now flow. About 35 miles south-east of Clifton Hill 

 Station, on the Diamentina, there are two parallel red sand ridges 

 traversing a stony plain in a north-north-westerly direction ; the 

 plain is covered with a pavement-like coating of flinty quartzite 

 stones. On the east side blocks and boulders of the same rock are 

 scattered about, amongst which are numerous low circular mounds 

 of white clayey sand, the centres of which are formed of blocks of 

 stones piled up, which are encircled by other smaller blocks, and 

 these by scattered stones, the whole bearing the appearance of 

 having been erupted by springs from below. At numerous other 

 places similar appearances present themselves ; mounds of sand, 

 gravel, and clay, and scattered stones occurring on the surface of 

 many of the plains and flat areas, the presence of which it is 

 difficult to account for in any other way, as there are no rocks at 

 a higher level in the neighbourhood from which the sand or gravel 

 could have been washed." 



As tending to support Mr. Brown's theory I may mention, that 

 great quantities of sand were forced up with the water in the tubes 

 of the artesian bore at Wee Wattah on the Killara Run in the 

 Darling District. 



The deep bore which is now being put down in the Cretaceous 

 area to the north of the " Government Gums," by Mr. J. W. 

 Jones, Head of the Water Conservation Department, S.A., has 

 reached to a depth of 1,100 feet in Cretaceous or Jurassic strata 

 without striking water. This is remarkable and shows how great 

 is the depth of this basin. In another locality good water has 

 been found in the Miocene Tertiary formation. 



