71 
continues for miles over more plains without having risen at all 
perceptibly to the eye in crossing the range. Doubtless exact 
measurements would show a good deal of variation in level, as the 
range appears to be a watershed between two drainage basins. 
Further north the plain runs along the foot of several hills, here 
mostly formed from the Nullagine beds, and everywhere the con- 
tact loctween the plain and the toes of the hills ]jreservcs its beach- 
like characteristics. 'Fhcre seemed to the writer to be no possible 
explanation of the extraordinary uniformity of level of the plain, 
and unbroken persistence of the beach typo of the edges of it, other 
than that it took its final shape from being covered by a sheet of 
water. It did not seem possil)lo to reconcile such extreme regu- 
larity of ])lanatioii with any known action of wind, or wind and 
rain combined, as erosive agents, d’hcrc must be a small rise and 
fall in the iilain country, however, for the road over it, though 
showing no grades very ])ercc])tit)lc in travelling, gradually passes 
from the watershed of the Gascoyne River on to that of the Ash- 
burton. 'j'he stock route wells along this track arc mostly sunk, 
apparently in deep soil, with sands and clayey little coherent strata 
beneath, of ju'ohalily quite recent age, but some of them seem to go 
into the Nullagine l)eds. 
At the llgarcre copper field we find great stretches of plain 
country, sparsely covered with ‘hnulga,” and often quite bare over 
considerable areas. 'These })lains resemble those usual further 
south in the F.asleni Goldfields, in being mostly covered on surface 
with a plentiful s])rink]ing of iron oxide and cherty gravel usually 
somewhat rounded, but possibly owing the rounded shajies more 
to concretionary growth in the case of the ironstone gravel and 
surface wear and weathering in that of the other stones than to 
water attrition. 'This feature will be considered later on. On the 
Avest side of one of these plains we come to some hilly country, 
composed of slates and basalt of the Nullagine series, and fairly 
deeply cut into by a nmnber of distinct "gullies.’’ evidently eroded 
by running water within the most recent times. One branch gully 
came up into the plain and could be seen to be partly cut out of it 
and to lie below its level. These watercourses were parts of the 
headwaters of the Ashburton River, and in them ordinary riv'er 
erosion is evidently proceeding rapidly now whenever storms sup- 
ply the necessary water to cause the streams to fill. The water- 
courses are evidently younger than the plains, and cutting back into 
them. This shows that the formation of the plains must date back 
some considerable distance in ])oint of time, and that there has been 
a change of conditions which has allowed of the starting of a cycle 
of river erosion, still in quite an early stage. 
PLAIXS — “breakaways” AXU SALT LAKES. 
In the East Murchison and Mt. Margaret Goldfields and south- 
wards from them to the south coast, we find ourselves in a region 
of small rainfall in which running streams are rare, and cases of 
