ARTESIAN WATER IK THE STATE OF QUEENSLAND, AUSTRALIA. 187 



artesian -water is met with iu " sand," and it has ah-eady been 

 mentioned that the "Braystone," when wet, is sand and 

 nothing more. It must be remembered that the " Bray- 

 stone" not only takes in all the rain that falls on it, 

 except what is accounted for by evaporation, but that it 

 receives also what is poured into it by the rivers already 

 referred to. 



The outcL-op of the "Braystone" is not visible for the 

 whole of the distance from north to south to which our 

 mapping extended, as it is partly concealed by nearly 

 horizontal table-lands of what has been called " Desert 

 Sandstone." The Desert Sandstone is an upper division of 

 the Cretaceous formation and lies unconformally on the 

 lower. Where it directly overlies the permeable Lower 

 Cretaceous strata it does not, however, seriously interfere 

 with the absorption of water by the latter, being itself of a 

 fairly permeable nature. 



But the loss of the rivers which flow across the outcrop of 

 the Braystone is itself sufficient to suggest a serious diffi- 

 culty. The Avater must, to some extent, escape, or the 

 Braystone could not continue to absorb it, and the rivers 

 would continue to run over the clay soil of the western 

 downs. It follows that these nnisthsive some outlet; and, 

 as has been pointed out by Professor David, of Sydney ; Mr. 

 E. Pittman, (Government Geologist of New South Wales ; and 

 Mr. W. S. Griffith, there are strong grounds for believing 

 that the underground water finds an outlet in the Great 

 Australian Bight. The sea-bed is not open to observation, 

 but if the water escapes where we suppose it does, the 

 Blythesdale Braystone must, after dipping and undulating 

 beneath the soil of the interior, crop out somewhere to the 

 south of Australia. This conjecture, as will be shortly seen, 

 is supported by observations on the water-pressures of the 

 artesian wells themselves. It is now almost equally certain 

 that a portion of the water escapes into the Gulf of 

 Carpentaria. 



7. Mr. MaitlancVs Vieics. — In a highly suggestive paper 

 read before the Royal Society of Queensland in April, 1896, 

 Mr. Maitland demonstrated that tlie principal artesian-water 

 basins of the world " are not disposed in the shape of those 

 ideal basins, sections of w^hich have done duty for many 

 years in geological maimals." The basins are, in fact, 

 irregular, in so far as the rim of the trough varies in altitude. 

 In other words the " basins " are in most cases " broken 



