12 IIOliN i;.\rKl)lTION — NAltUATIVK. 



,ui(l ill ;i,ll j)iol)a,l)ilit-y arc, idcuit iial with tho ".stony do.sui't " ot" 8turt's tlcscriptioii 

 of the iiiti:rioi', 



StnitcliinjL; away to I lie, horizon on cvory sido is a level plain covered with a 

 layer of jjiirple brown stones, va.i'yiii^ in siz(^ from an inch to perhaps a foot in 

 dianuilei', all made smooth by tlu; eonstaii t wealing away of wiiid-l)or'ne sand grains. 

 .Vmongst them in tlie dry s(!a.son are liei'e and then; a few small tussoeks of ytdlow 

 grass ; small li/.aids dart about, and innumerable grasshoppers rise; up from your 

 feet and fly for a short distance. 'Pliere is no water and no shelter; perhaps a lino 

 or two of thin mulga trcn-s far away will mark the course of a dry stream which 

 nica,nders about for a, shor( distance; as it comes down from some lowdying hill, 

 only to be soon losi- upon the plain. Except within a short time after rain it is 

 useless to look along its bed for water holes. The surface is dry and cracked, and 

 where the water stood longest are curled flakes of a glistening clayey nature. 



Nothing could be more desolate than a gibber plain when everything is bare 

 and dry, and the outline of the distant horizon is indistinct with the waves of 

 heated air. 



Throughout all this district the low flat-topped desert sandstone hills indicate 

 the original level of the land. All these hills have a thin capping of hard 

 chalcedoniz(!d sandst(tne ; when onc(! this is brokiMi up the softer undcndying rock 

 is rapidly disintegrated, and the sand particles into which it breaks up ai'e partly 

 carried away in Hood time, and partly blown away by heavy winds.* The iiarder 

 chalcedonized material gradually breaks up into blocks of various sizes, and these 

 become polished and rounded l)y the wind-bU)wn sand grains, while a thin coating 

 of oxide of iron gives them a redbrown and curiously polished appearance. As 

 the sand is gradually removed the polished stones come to form a layer spread over 

 the flat surface of the plains, the stones of which arc .so close to one another and 

 so regularly arranged that at times they look almost like a tesselated pavement. 

 In passing from the plains up the sides of the hills the gibbers can be seen in all 

 stages of formation, from the small, smooth and flattened pebble on the plain to the 

 big, irregularly shaped mass which has just tumf)led oil" from the exposed surface of 

 the thin desert sandstone capping of the hill. 



These stony gibber plains merge constantly into loamy plains covered with 

 poor scrub, but on which the gibbei'S are wanting. Perhajj.s, as suggested in the 

 section dealing with Geology, these loamy plains occupy areas on which the Upper 



* Stroii"- south-east winds duriiiK the winter months. 



