BY ROBERT L. JACK, F.G.S., F.R.G.S. 73 



Hodgkinson's traverse I mapped a portion of the watershed 

 between the Burke River and Cotton-Bush Creek as an inlier of 

 the metamorphic rocks. 



The earlier explorers traversed the country with a view, 

 almost entirely, to its cattle-carrying capacity, and from the 

 frequent references to " rolling downs " and " Mitchell grass " 

 up the Georgina River, I considered that I was justified in 

 regarding this portion of the colony as being of the same 

 character and origin as the " rolling downs " of the Western 

 interior. The unsuccessful bores already mentioned, however, 

 almost conclusively prove that metamorphic rocks are continuous 

 from the Cairns Range to the Cloncurry area, and either come up 

 to or very near the surface. 



I have searched in vain the broken records of Burke and 

 Wills' Expedition, in 1860-61 ; and the report of the Quecmlander 

 Expedition of 1879, for any indication of the geological structure 

 of this district. 



From all the information available up to this date I should 

 regard the district north of a line, about to be indicated, as 

 unfavourable country for the search for artesian water. The 

 line extends from the boundary of the colony, by the Tropic of 

 Capricorn, to the Georgina River, and thence north-eastward 

 (perhaps not in a straight line) to the head of the Warburton 

 River. The country north of this line, including the Cloncurry 

 area, may be either Archaean, Cambrian, or Silurian, or one or 

 other or all of these ; but for the present purpose the establish- 

 ment of an approximate north-western limit for the water-bear- 

 ing Cretaceous rocks is the essential point. 



Mr. Daintree, in 1872, in his paper on the " Geology of 

 Queensland "* recorded that a Tellina (a fossil so far as we know 

 not found in rocks older than Cretaceous) was " found in a bed 

 of horizontal limestone at the head of the Gregory, on the Barkly 

 Tableland, and forwarded to me by Rev. W. B. Clarke of 

 Sydney." While accompanying the Transcontinental Railway 

 Expedition in 1881, t I observed, behind the Police Barmcks, 

 on Carl Creek, " a hard yellowish limestone, horizontally 



* Quart. Jour. Geol. Soc, Vol. xxviii, p. 278. 



f Report on the Geological Features of part of the District to be traversed by the 

 proposed Transcontinental Railway. Brisbane : By Authority : 1885. 



