Sand Ridges in Wesieim Australia. 419 



^hat many of the other sand plains of inland Western Australia 

 jiiay be at least partly of wind origin. 



A somewhat parallel case occurs at Goongarrie, a mining 

 J:ownship 8 miles to the south of Comet Vale. The township is 

 situated on an unsymmetrical ridge the western side of which has 

 a gentle unbroken slope, but the eastern side is represented by a 

 line of low cliffs cut into small canyons by the short watercourses 

 v(almost always dry) which trend eastward to a small southward- 

 trending valley. The rocks of the ridge are serpentines and 

 iiornblendites, but the western slope is covered (only, however, to a 

 Kiepth of about six inches) by fine quartz sand of the origin of 

 which no other explanation can apparently be given than that it 

 lias been blown by the wind from the west up the slope. There are 

 -greenstone hills a little farther west, and beyond these extensive 

 isand plains. The sand could be, and probably has been, blown 

 rfrom the sand plains through a gap in the greenstone hills opposite 

 to the unsymmetrical ridge now referred to. An interesting 

 point is that portions of the sand on the western slope have l)een 

 blown over the crest of the ridge into the heads of the eastward- 

 i;rending watercourses above described, and that stream action is 

 carrying it to the lower portions of the valleys. Wind action on 

 i:he western slope has probaVjly been accelerated by the removal of 

 -a considerable portion of the native vegetation. 



An unbroken sloping plain of wind-blown sand remarkably 

 parallel in certain points to the Comet Vale and G<X)ngarrie 

 'examples, altliough on a much greater scale, has been described 

 ^yy Ball! in West-Central Sinai. Ihe plain of Debbet el Qeri rises 

 •gradually to the south, due to the prevalent northerly winds carry- 

 ing the sand along, with a gradual overflow into the heads of the 

 ■<ieeply-cut wadis draining southwards; the present tendency of the 

 •sand is to move southwards and choke the heads of the wadis. The 

 sand is covered witli scattered bushes, and its surface was level 

 ■enough to l^ used for the base line of Ball's triangulation. 



Direction of Past and Present Drift of the Sands. 



The distribution of the blown sands suggests that they have 

 -drifted easterly and that the dominant winds therefore have been 

 from the west. From limited observations made bv the writer in 



1 Ball, J.— "The GeogTRphy and Geolojry of West-Centrai Sinai." Snivey Departnieiit. Cairo, 

 •<Joverninent Press, 1916, pp. 87-8S, lli^. 



