78 



THE GEOLOGIST. 



underlying rock is seen in the bed of " Basalt " or " Limestone " creek ; it 

 is of a granitoid character, but Mount Caroline, the southernmost peak of 

 Perry's Range, is of altered slate, highly inclined, with numerous and 

 broad quartz reefs on the flanks, the summit being composed of syenite, 

 and this appears to be the character of the rocks of the Upper Clarke, 

 though blue fissile slate with quartz reefs is more abundant there. Mr. 

 Clarke has long ago pointed out this district as a future gold-field. The 

 fulfilment or otherwise of the prophecy is at hand. It was from drifts 

 overlying the Basalts of this district I obtained the bones of Diprotodon, 

 the most northern part of Australia in which, at present, the fossil re- 

 mains of this animal have been found. It is to these drifts that the cattle 

 in the neighbourhood come to lick, and I am of opinion it is more for the 

 phosphates from the bones of Diprotodon and his allies than from the chlo- 

 rides they contain. 



A well-defined crater exists at a point bearing S. 30° W. from Mount 

 Caroline, distant 36 miles. From the top of this an excellent view is ob- 

 tained of the boundary of the Basalt to the south. Granite spurs, gradually 

 sloping to the southern side of Fletcher's Creek, have checked its further 

 development in this direction. 



Looking westward, we have a gradual rise to the table-land forming part 

 of the watershed between the Flinders and Burdekin rivers, broken at in- 

 tervals by low isolated peaks or ridges. From this point may be seen the 

 Mount Mayne, etc., of Walker. South of this hill, about two miles, com- 

 mences what is called a " Basalt wall." This is said to extend in a south- 

 easterly direction as far as, and across, Fletcher's Creek, and I believe no 

 one had up to that period penetrated above this up Fletcher's Creek. 

 "Where I struck it it had the appearance of a walled city ruined by an 

 earthquake, the outer wall, though much rent, preventing the access of a 

 horseman to the debris lying within. Creepers and shrubs of great variety 

 grew over all, whilst a swampy bog at the base of its bluff margin, rich in 

 ferns, promised on the whole a harvest for the botanist, a safe retreat for 

 the blackfellow, and charming " little bits " for the artist or photographer. 

 I regret much that I could not devote the time to following down this 

 " Basalt wall," and more thoroughly exploring it. Whether it is the mar- 

 gin of an enormous crater, or a more recent lava-flow than that of the sur- 

 rounding level country, I had not leisure to investigate. These Basaltic 

 Lavas differ in no respect from those of probably the same age in Vic- 

 toria ; a suite of specimens collected on Xeilor Plains and on the Upper 

 Burdekin could not be distinguished the one from the other. A peculiar 

 feature of the Basaltic country here is, that the banks of the main, deep- 

 cutting creeks are very rocky, whilst the branch creeks are usually the 

 drains of open, gently-sloping well-grassed downs ; table-lands of lightly- 

 timbered and usually coarser-grassed country intervening between the 

 branch creeks. The timber on these table-lands is chiefly that known as 

 " stunted ironbark," and a remarkable feature is the absence of fallen 

 timber. This is attributable to the fact that the centre of nearly all the 

 trees is hollow, making them an easy and certain prey to the first bush-fire. 



Taking a general view of the geology of Queensland, as far as could be 

 obtained in such a flying visit, and from the reliable information I could 

 collect, it would appear that a belt of Upper Silurian rocks extends along 

 the coast from Brisbane to the neighbourhood of Broad Sound, and that 

 their strike being nearly parallel with the coast line, has mainly determined 

 its outline. Their dip, where observed, is north-easterly, at a high incli- 

 nation. The Maryborough and Roekhampton beds I w ould place at about 

 the same geological horizon ; lower in the series would come the gold-fields 



