40 



miles to the north. This plain, which seemed to be almost 

 level for a distance of about two miles after leaving the creek, 

 begins to rise before reaching the gate leading into the sheep 

 paddock, about one and a half miles north-east of Mandowna 

 Railway Station. About 40 yards within this enclosure funda- 

 mental rocks of a dark purple colour appear at the surface, 

 having a strike, as determined, of 45° west of north, and a dip 

 of 80° westerly. Prom the general appearance of the country 

 north and north-east of this place, these beds are extended 

 much further in these directions, probably constituting the 

 greatest part of the highlands between this point and the 

 River Proine. Passing on in a westerly direction, the surface 

 still rising and consisting of secondary strata, we bore straight 

 for the eastern side of Decoy Hill, the northernmost summit of 

 the Mount ISor'-West Eange, and about four and a half miles 

 slightly west of south from the Boorloo Springs. 



On ascending Decoy Hill, I found it to consist of a very 

 hard quartzite. I also found that on both sides of the band 

 the material was slightly less metamorphosed, and thinly 

 bedded, whilst the centre of the band was very hard and com- 

 pact, carrying blocks of considerable thickness ; strike, 50° 

 west of north ; dip, about 80° westerly ; estimated thickness, 

 about 200 feet ; locality, about four and a half miles — from 

 20° to 30° south of west from Hergott Eailway Station. The 

 water of the largest of the Boorloo Springs possesses very 

 nauseous properties, presumabl} r due to salt and sulphurous 

 ingredients. We stood by the spring and observed its motions 

 carefully for a short time, and noticed as its waters were 

 liberated at the surface of the pool an intermittent or an occa- 

 sional puff of gas was set free, indicative that gas of some 

 kind was generated in their passage to the surface. Besides 

 salt and sulphurous matter, the waters of the springs must 

 hold a considerable percentage of lime in solution ; for the 

 travertine thrown down around the outlet of the springs has 

 already accumulated to a height of from eight to ten feet 

 above the level of the surrounding plain. We ascended 

 another, which is situated a short distance north-east from the 

 main spring ; also a third, which seemed to be left in its 

 primitive state, located a few yards distant from the last, and 

 estimated that the outflow of the two smaller ones is barely 

 equal to the discharge of water from the main spring, though 

 to all appearance the travertine collected around them is quite 

 as great as the mound around the larger spring. This may 

 indicate that they are in process of extinction, or that they 

 have been longer in existence, if the discharge of water has 

 been equable from their commencement. The quartzite band 

 we had seen at Decoy Hill is continued in a northerly direction 



