20 INAUGURAL ADDRESS. 



sources of the rivers discharging into the Gulf of Carpentaria ; from 

 the Albert River to Brisbane he followed Leichhardt's route of 1844. 

 This extraordinary achievement is second to none in point of 

 interest, of unknown country traversed, and of the scientific results 

 gained ; a vast void in the geological map was filled in. 



The geological structure of the gorges of the Victoria River inland 

 from Sea Range (which had already been described by Stokes as 

 consisting of horizontally-bedded sandstone overlying inclined 

 metamorphic rocks) is described by Gregory* as follows : — 



1 . Thick bed of red sandstone, overlain by ironstone gi*avel. 



2. 'Ihick compact bed of siliceous sandstone, with indistinct 



stratirication, generally exceeding 300ft, ; at Sea Range a 

 softer whitish sandstone, 100ft. thick, separates this forma- 

 tion into three bands. 



3. Bluish shale or clay slate. 



4. Limestone of unknown thickness, covered with a stratum of 



jasper varying from a few inches to 60ft. in thickness. 



WiLSONf says — "The rocks composing the tableland are 

 Palaeozoic, and, with the exception of a few beds of trap and an 

 occasional prominence of granite, belong to the Carboniferous." 

 The siliceous sandstones he places on the horizon of the Hawkes- 

 bury series of New South Waies, but describes as differing from 

 them in the absence of drift-bedding and organic remains. The 

 cliffs on the north-west coast he regards as partially reconstructed 

 ferruginous sandstone belonging to the Tertiary period. 



Since Gregory's expedition the interior of Australia has been 

 traversed in various directions, and with such eft'orts are honorably 

 associated the names of Stuart, Burke and Wills, Warburton, 

 Giles, J. Forrest, &c., but the geological gain has been of a purely 

 local importance. I may therefore be pardoned if I single out for 

 mention that recently fitted out by — 



SiK Thomas Elder. The object — to fill up the blank spaces 

 in the topographical and geological maps of Australia — was 

 ambitious, and the scientific equipment of the expedition gave 

 hojie that permanent results would be gained ; but its premature 

 disbandment has indefinitely protracted the realisation of this 

 cherished consummation. So far as the area traversed is concerned 

 the expedition accomplished a very great deal ; it was a failure 

 simply by reason of the limitation of the original scheme. In 

 geology nothing new has been brought to light, though certainty has 



» Journal of the N.W. Australian Expedition, Pail. Kcii. 1861. 

 t Journal Royal Geographical Society, vol. xxvni. 



