92 Proceedings of the Royal Society of Victoria. 



of the Macedon district in Victoria, to be afterwards described. 

 An analysis of a specimen of trachyte from (xladstoae is given 

 by Professor Liversidge in his "Minerals of New South Wales," 

 1888, p. 229. 



Trachyte was discovered in New South Wales in the Coona- 

 barabran district in 1895.^ This is stated to be the tirst trachyte 

 found in that colony, but in a paper dealinj^ with " The Cupri- 

 ferous Tuffs of the passage beds between the Triassic Hawkes- 

 bury series and the Permo-carboniferous Coal-measures of New 

 South Wales, "'^ Professor David records a " greyish-pui'ple tra- 

 chyte lava." No description of the rock is given, and it is 

 possible that the writer was using the term " trachyte " in its 

 older and looser sense. The Rev. J. Milne Curran, F.G.S., in 

 a paper entitled " Microscopic Structure of some Australian 

 Rocks, "'^ had also noted a trachytic lava from the junction of 

 Rocky Bridge Creek and the Lachlan River in New South 

 Wales prior to 1895. From his brief description of the rock it 

 is not clear how he arrived at his determination of the character 

 of the leading felspar. A trachytic tuff is reported from the 

 Manning River.^ 



I have not traced the occurrence of trachyte either in South 

 or Western Australia. At a meeting of the Royal Society of 

 Tasmania, held on 11th April, 1899, a paper was read by Messrs. 

 W. H. Twelvetrees, F.G.S., and W. F. Pettard, F.G.S., describ- 

 ing the occurrence of haiiyue-trachyte among the igneous rocks 

 of Port Cygnet and Oyster Cove, Tasmania. 



The presence of sanidine in the igneous rocks of Victoria was 

 first noted by Mr. J. Dennaut, F.G.S. At the Adelaide meeting 

 of the A.A. A.S., 1893, in a paper entitled "Notes on the Igneous 

 Rocks of South-Western Victoria," he described a series of sani- 

 dine-bearing rocks occurring in the district. From the map 

 attached to his paper, it may be seen that these rocks h;ive a 

 very considerable extension. His researches led him to conclude 

 that they were not phonolites, but he does not appear to have 

 recognised their character as trachytes, as in his map they are 



1 G. W. Card. Records of the Geol. Survey of New South Wales, vol. iv., part iii., 1895. 



2 Proc. A.A.A.S., vol. i., Sydney, 1SS7, i>. 'iSO. 



» Proc. Roy. Soc. New South Wales, 18!)1, vol. xxv., pp. 220-'221. 



4 G. W. Card. Records of the Geol. Survey of New South Wales, vol. v. part L, 1S96. 



