41 



quite as far as the Boorloo Springs, which iu its course appears 

 on the rising ground about three-quarters of a mile westerly 

 of them. Here it has become metamorphosed into a quartz. 



Leaving the Springs, we proceeded crossing a flat about 

 three miles north-west of the Hergott Railway Station, and 

 followed the track leading nearly west over a tableland until 

 we abruptly descended into Collanna Creek. The eastern sec- 

 tion at this creek has, at a distance of about seventy yards 

 from the bed of the creek, an altitude of about one hundred 

 feet. The lower portion of this section consists of a clayey 

 material, with flakes of selenite scattered throughout, evidently 

 the waste of an argillaceous bed, the upper portion consisting of 

 variously-sized pebbles, averaging from four to nine inches in 

 diameter. The wasting away process is here carried on more 

 rapidly in the clayey deposits than it is in the conglomerates, 

 hence the latter become undermined, and finally fall in large 

 blocks, soon to become disintegrated, the pebbles getting pro- 

 fusely scattered over the slopes and base of the cliff. Further 

 up the creek, but on the opposite side, there is a bluff of 

 secondary strata, without the conglomerate cover, higher than 

 the other including its capping of pebbles. The presence of 

 these conglomerates imbedded on the surface of the plain at 

 so high a level above the bed of the creek leads me to suppose 

 that before the ravine was cut through the secondary beds, the 

 creek emptied its waters over the plain at this place, hence the 

 presence of boulders of a primitive type so high above the level 

 of the modern channel. 



Leaving Collanna Creek, for a short distance we passed over 

 sua undulating, or rather a knolly country, similar geologically 

 to the foregoing, excepting that there were not so many stones 

 of a primitive character scattered over the surface. On as- 

 cending any small height we could descry in the distance to 

 the south hills presenting a semi-chalky aspect on their nor- 

 thern slopes. Coming to the "Welcome Springs we found them 

 situated in a valley about twenty feet below the level of the 

 plain. The question arose, from whence came so large a volume 

 of water sufficient to cut a channel deep enough to expose and 

 liberate the waters of the various springs? A moment's reflec- 

 tion led me to consider that I had seen hills and tablelands to 

 the south and south-west sufficiently high to collect and dis- 

 charge from their summits flowing water, which in time may 

 have scooped out a channel of these dimensions across the plain, 

 and deep enough to liberate the waters of the springs. The 

 water from the largest spring was a little more palatable than 

 that we got at the Boorloo, though it has a peculiar sulphurous 

 taste and smell. Travertine in large quantities has been thrown 

 down around the two lesser springs which I examined, whilst very 



