THE NATURE. OCCURRENCE. AND ORIGIN OF 



ALUNOGEN AT VANDYKE. NEARSPRINGSURE, 



CENTRAL QUEENSLAND. 



By H. C. Richards, D.Sc, Lecturer in Geology, University 

 of Queensland. 



(With two Text-fignres). 



{Bead before the JRoyal Society of Queensland, 28th October, 



1918.) 



In the October number of the Queensland Government 

 Mining Journal for 1916, Mr. B. Dunstan, F.G.S., \vhi]e 

 dealing Mdth aluminium referred to a deposit of alunogen 

 or basic aluminium sulphate which occurs at Vandyke, 

 some 16 miles south-east of Springsure. A brief account of 

 the nature and occurrence of the deposit was given, also 

 an analysis which had been carried out in the Agricultural 

 Chemist's Laboratory. 



It has been known for some time that in the neighbour- 

 hood of Springsure there are alkaline trachytic rocks rich in 

 potash-felspar. While potash-felspar rocks are not usually 

 utilised as a soiirce of potash it sometimes happens, as at 

 Bulladelah. in New Soiith Wales, that potassium aluminium 

 sulphate deposits (alunite) occur in the form of veins 

 through the rock owing, it is believed, to the attack of 

 vapours such as sulphurous acid. 



Queensland like many other places has, since the advent 

 of the war, suffered a potash famine and the fruit-growing 

 industry in particular has been much affected. Con- 

 sequently the writer felt that with potash-rich volcanic 

 Tocks in the Springsxire district and also an aluminium 

 sulphate deposit the conditions for the occurrence of alunite 

 might be favourable. As alunite by the simple process of 



