Clarke. — Natural licffions in U'cstern Australia. 
125 
Gum association of the Kalgoorlic Kegioii. It should be )ioted, 
however, that the 8i)iiiifex association so characteristic of the country 
to the east, makes considerable inroads into the Murchison Kegion. 
Although much mineral wealth has been and will be obtained 
in this region, it was first settled by pastoralists and is now the most 
important sheep-carrying area of the State. It has greater drought 
resistance than the Kalgoorlie Region J)ecause of the almost uni- 
versal presence both of good Avell -water and edible shrubs. The 
N.E. boundary has been extended to long. 124°, lat. 26°, into an area 
of probably Proterozoic rocks, so as to include the good pastoral 
country of Wongawall (Talbot, 1920, ]). 16), which seems less out 
of place here than in the Carnegie Region. 
8. Carnarvon Megion. This region is entirely composed of sedi- 
mentary rocks with, generally, a gentle Avesterly dip, l)ut there is, 
according to Mr. R. J. Naiikivell, gentle folding along a N.N.W. 
axis between the Wooramel and Minilya rivei’s. It coincides with 
the Nortli-AVest Artesian 15asin (Maitland, 1919, c.), and is thus 
very definitely distinct from the country to the north. Its oldest and 
easternmost rocks are ^‘Permo-Carboniferous,^’ folloAved by Jurassic, 
which are in turn overlain by Cretaceous and younger rocks. 
Its southern portion, lying on the border betAveen areas of 
summer and Avinter rain, has an average annual rainfall of less than 
10 inches, and the rainfall shoAvs Avide variation from year to year. 
The northern portion has an average of more than 10 inches, and 
lies distinctly Avithin the area of summer rain. IIoAvever, in vieAv 
of the persistence of other characters, this difference in rainfall is 
not sufficient ground for dividing the area into two regions. 
I am indebted to Mr. R. J. NankiAudl for a description of the 
topography and A’egetation. The region seems particularly difficidt 
to describe in a general way. Its relief is mild, the hills, Avlnch are 
residuals of erosion of the cuesta or escarpment or butte type, aie 
neither lofty nor numerous, but, though they rise only in a feAV 
places as much as 1000 feet aljove sea-level, they are very conspicuous 
because of their steepness. The soil is predominantly sand or sandy 
loam, but clay soils are fairly common in the southern portion, and In 
some places are areas of limestone-derived soil. Much of the coun- 
try is therefore very porous, and conse(|uently reticulation ftom 
artesian Avells is costly. The entire region is descril^ed as excellent 
pastoral country, although in parts there is the Avater-su[>i)ly difficulty 
just mentioned, and in the northern section the Avater so far obtained 
is said to be generally saline. 
The covering of shrubs — chiefly Mulga and othei Leguniinosae 
— is fairly dense in the southern portion, and is of value aa fodder, 
