414 J. T. JtUson: 



ferruginous laterite, the chief of which is a ridge bearing north- 

 north-west on the western side of the belt. The latter is separated' 

 on the east from the area now to be described by a deep, but 

 mostly wide, open valley, (b) A belt of greenstone lying to the 

 east of (a) and bounded on the east by the *' dry " lake or playa, 

 Lake Goongarrie. This belt is deeply dissected by narrow V- 

 shaped radial valleys in tlie adolescent or early mature stage. 

 The crests of (a) and (b) are about 100 feet above the floor of the- 

 lake. 



(2) Lake Goongarrie forms an extensive " dry " lake or playa 

 having on its western shore greenstone cliffs which form part of (b),. 

 and having on its northern and north-eastern shores sand ridges. 



(3) Gently undulating sand plains lie to tflie west, north and 

 north-west of the township, and on these plains rest sand ridges 

 of varying height (the highest probably being 50 or 60 feet above 

 the plains) and having an approximately east and west trend. 

 The sand plains are broken by occasional small " dry " lakes. No< 

 watercourses exist in this belt, as the sand inmiediately absorbs the 

 rain. Just to the east of the railway the sand overlies a rather 

 coarse ironstone " wash," a few feet thick, which in turn overlies 

 the bedrock, greenston*?. 



Vegetation of the Sand Plains and Sand Ridges. 



Slight differences exist between the vegetation of the sand plains 

 and that of the sand ridges. 



On the sand plains there are two types, which may be termed 

 the acacia type and the eucalyptus-" spinifex " type, the acacias 

 or the eucalyptus and ** spinifex " predominating as the case may 

 be. The eucalypts are of the stunted branching-from-the-root type 

 known as '' mallee " eucalypts. The two types may in places more 

 or less merge into one another, but over considerable areas they 

 are substantially distinct. 



On the sand ridges the vegetation can hardly be divided for the 

 purposes of this paper into distinct types, but some characteristics 

 may be noted. The mallee eucalypts grow on the sides of some 

 ridges, but usually cease before the top is reached. The acacias 

 may grow both on the top and sides, and likewise the spinifex; 

 but as a rule spinifex and acacias are not commonly found to- 

 gether. The tops of the ridges may be ^stitute of tall shrubs and 

 trees, and in this case the spinifex usually grows, associated 

 with low, often sprawling shrubs. 



