CXXIV. IRRIGATION GEOLOGICALLY CONSIDERED. 
being any unconformity between the two formations. It 
should be mentioned that the Queensland Geologists state 
that they have observed such unconformity in parts of their 
territory, but their descriptions leave it an open question 
as to how far the phenomena recorded may be due to con- 
temporaneous erosion rather than to unconformity. 
The Intake Beds.—The intake beds consist of porous - 
freshwater sandstones of the Triassic series. These beds 
extend into New South Wales from Queensland, and are 
first seen on the Dumaresy (Sovereign) River at a point 15 
miles west of the township of Texas. The eastern margin 
of the intake beds in New South Wales can be traced thence 
inaS8.8.W. direction as far as Dubbo. As already stated, 
they form part of the western flanks of the Dividing Range. 
They have an average width of probably 60 miles. They 
dip gently westwards, and it is believed that they are con- 
tinuous under the Cretaceous rocks for the whole width 
at least of the portion of the artesian area which lies in 
this State. For example, at Salisbury Downs, west of 
Wanaaring, the characteristic Triassic fossil Toeniopteris 
Daintreei, was obtained from near the bottom of the bore. 
This point is about 400 miles west of the eastern boundary of 
the intake beds. The series consists of shales, sandstones 
and coal seams, and their aggregate thickness in places, 
as for example at the Wallon and Bulyeroi Bores is at 
least 2,000 feet, but of this thickness only a small portion 
is made up of the porous beds which occur at intervals in 
the series. In places the intake beds are of a very porous 
character, as for example hear Wallangra, and between 
Yetman and Texas. Atthe last named area the sandstones 
have undergone considerable disintegration giving rise to 
a thick superficial covering of sand, about 20 miles in width. 
As regards altitude the intake beds attain an elevation of 
about 1,200 feet above sea level between Texas and Yetman. 
