Wa 
" 
water occurs in coal-measures of Mesozoic Age, as has 
been proved from the occurrence in them of Sagenopteris, | 
found by one of us (H. F. Pittman) and recognised as such 
by R. Etheridge, Junr. The coal is being worked near the 
outcrops of theseams. ‘The basin rests on a floor of granite, 
and the greatest altitude of the Mesozoic rock is towards 
the north, the dip being in a southerly direction. Several 
bores have been put down to prospect for coal to depths of 
over 1,000 feet, (?) and these have been overflowing at the 
surface with artesian water for several years. As Sagen- 
opteris occurs also in the Ipswich Coal-measures of Queen- 
land, the age of which is generally considered to be Triassic, 
the artesian strata of the Collie Coal-field may be referred 
provisionally to the same age. 
CX. : IRRIGATION GEOLOGICALLY CONSIDERED. 
(3) The Main Artesian Basin of Australia.—The main 
artesian basin of Australia lies chiefly in Queensland, 
extending on the S.W. into South Australia, and towards 
the S.E. and S. into New South Wales. Commencing at 
the Gulf of Carpentaria and taking in the greater part of 
Oape York Peninsula, it trends southerly and follows 
approximately, as regards its eastern boundary, the outline 
of the adjoining coast, the distance between its eastern 
margin and the coast varying from about 100 to 300 miles. 
Its southernmost development in New South Wales is in the 
neighbourhood of Dubbo, and as already stated, it extends 
' This remark applies to that portion of the basin which has proved to 
be productive of artesian water. The fact, however, must not be lost 
sight of that the Triassic rocks (which usually form the storage beds of 
the artesian water) extend from near Toowoomba in an easterly and 
southerly direction to the coast, connecting with the Clarence Basin 
already described. All bores, however, put down in this extension east 
of Toowoomba, have hitherto proved unproductive. Dr. R. L. Jack, F.4.s. 
late Government Geologist of Queensland, is of opinion that there may 
be a concealed ridge of Gympie (Carboniferous) rock which may cut off 
at a depth the Clarence and Brisbane Trias ‘basin from the main artesian 
area. ROLE sate pee ee 
