316 PEOCEEDESTGS OF THE GEOLOaiCAI SOCIETY. [April 24 



On the Burnet river, in Southern Queensland, melaphyres of the 

 same character are met with. 



The Desert Sandstone is seen resting on the Agate-Creek mela- 

 phyres, and also on the " older volcanic " dolerites near Morinish, in 

 fine sections ; and, where available, this would afford the best guide 

 for the separation of the two great Tertiary volcanic periods of 

 Queensland. It also gives a good relative horizon to that great un- 

 fossiliferous sandstone formation which, as previously mentioned, 

 seems to have extended during the Cainozoic period over the greater 

 portion of Australia. 



The volcanic soils of Queensland are those best adapted for the 

 grazier and agriculturist. 



To epitomize : — 



It may be stated that, with the exception of the McKinlay ranges, 

 a line drawn parallel to the eastern coast, at a distance of 250 

 miles, would include all the palaeozoic, metamorphic, granitic, trap- 

 pean, and volcanic rocks represented in the colony, both coal-groups 

 lying within the same area. 



The Mesozoic and Cainozoic systems occupy the surface area to the 

 westward. 



The volcanic rocks follow the line of greatest elevation on the main 

 watershed, at altitudes from 1500 to 2000 feet above the sea-level. 



The descent, going eastward, is first, locally, a thin capping of De- 

 sert Sandstone, next Carboniferous, then Devonian (and possibly SUu- 

 rian), with patches of metamorphic and granitic rocks interspersed. 



The chief granitic mass extends from Broad Sound to Cape York*, 

 with an occasional capping of Desert Sandstone. 



Westward from the dividing range. Desert Sandstone and the Cre- 

 taceous and Oolitic groups alternate one with the other to the extreme 

 limit of the colony. 



Areas of Formations. 



Estimating the entire extent of the colony at 600,000 square miles, 

 a rough approximation to the areas occupied by the different geo- 

 logical formations is as follows : — 



Square miles. 



AUuvial 20,000 



Desert Sandstone Cainozoic .... 150,000 



OolitTc'''''' } Mesozoic .... 200,000 



Carbonaceous Mesozoic .... 10,000 



Carboniferous PALiEozoic .... 14,000 



Devonian and Upper Silurian Palaeozoic .... 40,000 



Metamorphic 20,000 



Granitic (including Cape- York peninsula) 114,000 



Trappean 12,000 



Yolcanic 20,000 



600,000 



* See also Quart. Journ. Gaol. See. vol. xxv. p. 297 ei seq., for an account of 

 the granite and other rocks of the Cape-York peninsula. 



