13 Dr. Fitton on the Geology of Australia. 



north of Morgan's Island, is composed, at the base, of granite; 

 and Mount Caledon, on the west side of Caledon Bay, seems 

 likewise to consist of that rock, as does also Melville Island. 

 This part of the coast has afforded the ferruginous oxide of 

 manganese: and brown hematite is found hereabouts in con- 

 siderable quantity, on the shore at the base of the cliff's ; forming 

 the cement of a breccia, which contains fragments of sand- 

 stone, and in which the ferruginous matter appears to be of 

 very recent production; — resembling, perhaps, the hematite 

 observed at Edinburgh by Professor Jameson, around cast- 

 iron pipes which had lain for some time in sand*. 



The general range of the coast, it will be observed, from 

 Limmen's Bight to Cape Arnhem, is from south-west to north- 

 east ; and three conspicuous ranges of islands on the north- 

 western entrance of the Gulf of Carpentaria, the appearance 

 of which is so remarkable as to have attracted the attention of 

 Captain Flinders f, have the same general direction: a fact 

 which is probably not unconnected with the general structure 

 of the country. The prevailing rock in all these islands ap- 

 pears to be sand-stone. 



The line of the main coast from Point Dale to the bottom 

 of Castlereagh Bay, where Captain King's survey was resumed, 

 has also a direction from south-west to north-east, parallel to 

 that of the ranges of islands just mentioned. The low land 

 near the north coast in Castlereagh Bay, and from thence to 

 Goulburn Islands, is intersected by one of the few rivers yet 

 discovered in this part of Australia,— a tortuous and shallow 

 stream, named Liverpool River, which has been traced inland 

 to about forty miles from the coast, through a country not more 

 than three feet in general elevation above high-water mark; 

 the banks being low and muddy, and thickly wooded : And 

 this description is applicable also to the Alligator Rivers on 

 the south-east of Van Diemen's Gulf, and to the surrounding 

 country. The outline of the Wellington Hills, however, on 

 the mainland between the Liverpool and Alligator Rivers, is 

 jagged and irregular ; this range being thus remarkably con- 

 trasted with the flat summits which appear to be very nu- 

 merous on the north-western coast. 



The specimens from Goulburn Islands consist of reddish 

 sand-stone, not to be distinguished from that which occurs be- 

 neath the coal formation in England. On the west of these 

 islands the coast is more broken, and the outline is irregular: 

 but the elevation is inconsiderable ; the general height in Co- 

 bourg Peninsula not being above one hundred and fifty feet 



* Edin. Phil. Journ., July, 1825, p. 193. 

 f Flinders, vol. ii. p. 158. — See hereafter. 



above 



