BY THE REV. J. MILNE CURRAX, F.G.S. 173 



country known as Ironbark Ridges the formation seems to 

 consist of very thick beds of conglomerates. It is visible in 

 the valleys and on the hill tops — quartz and felspar pebbles 

 cemented by a ferruginous paste. On sinking it is found to be 

 a comparatively thin layer on the surface. The explanation is that 

 the pebbles are probably all that remain there of many hundred 

 feet of rock through which they were distributed. The cementing 

 is an altogether subsequent work. 



It was reported that a thick bed or beds of conglomerate was 

 cut through in the diamond drill bore put down near Dubbo by 

 the Railway Department, but from an examination of the cores, I 

 can say that the conglomerate so called barely meiits to be 

 described as a pebbly sandstone. True conglomerate is an excep- 

 tional formation in the District. 



Between the Brick Yards platform and Murrumbidgeree Station 

 the Palaeozoic rocks disappear and the first section of the sandstone 

 is seen. 



This is the extreme edge of the basin, for limestone crops out in 

 a creek a few yards to the north of the railway fence. From this 

 the sandstones and shales continue, with occasional patches of 

 basalt, until granite is met at 289-10 miles. Throughout this 

 distance every visible section shows wavy beds forming small 

 basins without any appreciable general dip. Nowhere is the dip 

 greater than 5°. 



Before meeting the granite at 289 miles a remarkable instance 

 of metamorphism may be seen. A ferruginous i-ock with irregular 

 concretions or rather patches of darker colour, contains water worn 

 pebbles. A few chains further it grows more compact and a 

 crystalline structure is gradually developed. Further on it might 

 be called a Binary Granite with flesh coloured felspar. 



Beyond this again the sandstone' and ferruginous grits appear, 

 then granite continues for about six miles. 



About 293-60 miles an exceptional condition presents itself. 

 Instead of the usual friable and horizontal beds, the rocks, compact 



